Publications by category
Journal articles
Roy A, Sundaram S, Nandhakumar M, Thangaian DT, Subramanian B (In Press). An Enduring in vitro Wound Healing Phase Recipient by Bioactive Glass-Graphene Oxide Nanocomposites. Scientific Reports
Bhandari S, Roy A, Ali S, Mallick T, Sundaram S (In Press). Cotton soot derived carbon nanoparticles for NiO supported processing temperature tuned ambient perovskite solar cells. Scientific Reports
Bhandari S, Roy A, Ali S, Mallick T, Sundaram S (In Press). Cotton soot derived carbon nanoparticles for NiO supported processing temperature tuned ambient perovskite solar cells. Scientific Reports
Roy A, Sundaram S, Mallick T (In Press). Cu2ZnSnS4, a Fascinating Counter Electrode for TiO2-Free Dye-Sensitized Solar Cells. Chemistry Select
Roy A, Sundaram S, Mallick T (In Press). Effect of dye sensitization’s temperature on ZnO-based solar cells. Chemical Physics Letters
Roy A, Velusamy S, Sundaram S, Mallick T (In Press). Eggshell Membrane Assisted CdS Nanoparticles for Manganese Removal. Advanced Materials Letters
Roy A, Ghosh A, Benson D, Mallick T, Sundaram S (In Press). Emplacement of screen-printed graphene oxide coating for building thermal comfort discernment. Scientific Reports
Sheikh MS, Roy A, Bhandari S, Mallick T, Sundaram S, Sinha TP (In Press). Highly conductive double perovskite oxides A2LuTaO6 (A= Ba, Sr, Ca) as promising photoanode material for dye sensitized solar cells. Materials Letters
Roy A, Ghosh A, Bhandari S, Mallick T, Sundaram S (In Press). Incorporating Solution-Processed Mesoporous WO3 as an Interfacial Cathode Buffer Layer for Photovoltaic Applications. The Journal of Physical Chemistry Part A: Molecules, Spectroscopy, Kinetics, Environment and General Theory
Roy A, Bhandari S, Sundaram S, Mallick T (In Press). Intriguing CeO2-TiO2 hybrid nanostructured photoanode resulting up to 46% efficiency enhancement for dye-sensitized solar cells. Materials Chemistry and Physics
Roy A, Bhandari S, Ghosh A, Mallick T, Sundaram S (In Press). Performance of WO3 Incorporated Carbon Electrodes for Ambient Mesoscopic Perovskite Solar Cells.
ACS OmegaAbstract:
Performance of WO3 Incorporated Carbon Electrodes for Ambient Mesoscopic Perovskite Solar Cells
The stability of perovskite solar cells (PSC) is often compromised by the organic hole transport materials (HTMs). We report here the effect of WO3 as an inorganic HTM for carbon electrodes for improved stability in PSCs which are made under ambient conditions. Sequential fabrication of the PSC was performed under ambient conditions with mesoporous TiO2/Al2O3/CH3NH3PbI3 layers and, on the top of these layers, the nanoparticles embedded carbon electrode was used. Different concentrations of WO3 nanoparticles as HTM incorporated in carbon counter electrodes were tested, which varied the stability of the cell under ambient conditions. The addition of 7.5% WO3 (by volume) led to a maximum power conversion efficiency of 10.5%, whereas the stability of the cells under ambient condition was ~350 h, maintaining ~80% of the initial efficiency under light illumination. At the same time, the higher WO3 concentration exhibited a high efficiency of 9.5%, which was stable up to ~500 h with a loss of only ~15% of the initial efficiency under normal atmospheric conditions and light illumination. This work demonstrates an effective way to improve the stability of carbon based perovskite solar cells without affecting the efficiency for future applications.
Abstract.
Roy A, Mukhopadhyay S, Parukuttyamma SD, Sundaram S (In Press). Polyaniline Layered Rutile TiO2 Nanorod as an Alternative Photoanode in Dye Sensitized Solar Cell. ACS Omega
Roy A (In Press). Role of vanadium ions substitution on spinel. MnCo2O4 towards enhanced electrocatalytic activity for hydrogen generation. Scientific Reports
Roy A, Ullah H, Ghosh A, Baig H, Sundaram S, Tahir A, Mallick T (In Press). Understanding the Semi-switchable Thermochromic Behavior of Mixed Halide Hybrid Perovskite Nanorods. The Journal of Physical Chemistry C: Energy Conversion and Storage, Optical and Electronic Devices, Interfaces, Nanomaterials, and Hard Matter
Sadhukhan P, Roy A, Bhandari S, Mallick TK, Das S, Sundaram S (2023). Achieving high open circuit voltage for hole transport layer free ambient perovskite solar cells utilizing electric double layer effect.
Solar Energy Materials and Solar Cells,
251Abstract:
Achieving high open circuit voltage for hole transport layer free ambient perovskite solar cells utilizing electric double layer effect
One of the features of perovskite solar cells (PSCs) that make them stand out among all photovoltaics (PVs) is their high open-circuit voltage (VOC). Owing to their simple manufacturing process, low cost of components, and good stability, carbon electrode-based metal-halide PSCs are gaining interest for their better stability and low cost than noble metal electrodes. However, carbon electrode-based hybrid PSCs suffer low open-circuit voltage (VOC). This work demonstrated the fabrication of ambient processed hybrid perovskite solar cells using low-temperature curable carbon-based electrodes without a hole transport layer. The devices exhibit an impressive high open circuit voltage of 1.07 V, even without a dedicated hole transport layer. The photovoltaic performance was further investigated with the same perovskite absorber, synthesized by solution-processed and solid-state synthesis routes. The latter have yielded better short circuit current and power conversion efficiency due to perovskite's lesser built-in trap density. Furthermore, using a combined ionic electronic carrier transport model, an electric double-layer formation was ensured across the perovskite/carbon interface and accumulating halide vacancies at the perovskite/TiO2 interface can effectively reduce carrier recombination and boost the device's VOC. This study envisages the impact of the electric double layer in free carrier transport of an ionic-electronic semiconductor like hybrid perovskites and can pave the way to improve the open-circuit voltage of carbon-based perovskite solar cells.
Abstract.
Roy A, Ding B, Khalid M, Alzahrani M, Ding Y, Tahir AA, Sundaram S, Kinge S, Asiri AM, Slonopas A, et al (2023). Certified high-efficiency "large-area" perovskite solar cells module for Fresnel lens-based concentrated photovoltaic. iScience, 106079-106079.
Valsalakumar S, Roy A, Mallick TK, Hinshelwood J, Sundaram S (2023). Mesoporous TiO2-layer’s rheological impact on the perovskite solar cell performance. Materials Letters, 337
Al-Fartoos MMR, Roy A, Mallick TK, Tahir AA (2022). A Short Review on Thermoelectric Glazing for Sustainable Built Environment.
Energies,
15(24), 9589-9589.
Abstract:
A Short Review on Thermoelectric Glazing for Sustainable Built Environment
Securing net-zero targets by employing sustainable materials for the built environment is highly desirable, and this can be achieved by retrofitting existing non-smart windows with thermoelectric (TE) glazing, providing improved thermal performance along with green electricity production. It is reported that TE glazing could produce ~4000 kWh of power per year in a cold climate with a temperature differential of ~22 °C. This feature of TE materials drives their emplacement as an alternative to existing glazing materials and could lead to the identification of optimum solutions for smart window development. However, few attempts have been made to employ TE materials in glazing. Therefore, in this brief review, we discuss, for the first time, the efforts made to employ TE in glazing, identify their drawbacks, and discuss potential solutions. Furthermore, the working principle, suitable materials, and methods for developing TE glazing are discussed. In addition, this article introduces a new research area and provides researchers with detailed instructions on how to build and optimize this system. The maximum efficiency of a thermoelectric material is determined by its thermoelectric figure of merit, which is a well-defined metric to characterize a device operating between the hot-side and cold-side temperatures. TE material’s figure of merit promises new perspectives on the conceivable future energy-positive built environment. The role of TE in tackling the energy crisis is also discussed, since it provides sustainable energy alternatives
Abstract.
Sen S, Roy A, Sanyal A, Devi PS (2022). A nonenzymatic reduced graphene oxide-based nanosensor for parathion.
Beilstein Journal of Nanotechnology,
13, 730-744.
Abstract:
A nonenzymatic reduced graphene oxide-based nanosensor for parathion
Organophosphate-based pesticides (e.g. parathion (PT)) have toxic effects on human health through their residues. Therefore, cost-effective and rapid detection strategies need to be developed to ensure the consuming food is free of any organophosphate-residue. This work proposed the fabrication of a robust, nonenzymatic electrochemical-sensing electrode modified with electrochemically reduced graphene oxide (ERGO) to detect PT residues in environmental samples (e.g. soil, water) as well as in vegetables and cereals. The ERGO sensor shows a significantly affected electrocatalytic reduction peak at −0.58 V (vs Ag/AgCl) for rapid quantification of PT due to the amplified electroactive surface area of the modified electrode. At optimized experimental conditions, square-wave voltammetric analysis exhibits higher sensitivity (50.5 μA·μM−1·cm−2), excellent selectivity, excellent stability (≈180 days), good reproducibility, and repeatability for interference-free detection of PT residues in actual samples. This electrochemical nanosensor is suitable for point-of-care detection of PT in a wide dynamic range of 3 × 10−11–11 × 10−6 M with a lower detection limit of 10.9 pM. The performance of the nanosensor was validated by adding PT to natural samples and comparing the data via absorption spectroscopy. PT detection results encourage the design of easy-to-use nanosensor-based analytical tools for rapidly monitoring other environmental samples.
Abstract.
Valsalakumar S, Roy A, Mallick TK, Hinshelwood J, Sundaram S (2022). An Overview of Current Printing Technologies for Large-Scale Perovskite Solar Cell Development.
Energies,
16(1), 190-190.
Abstract:
An Overview of Current Printing Technologies for Large-Scale Perovskite Solar Cell Development
The power conversion efficiencies (PCEs) of Perovskite solar cells (PSCs) have seen significant performance improvements between 2012 and 2022. PSCs have excellent optoelectronic properties and can be built using low-cost materials. In order to compete with first-generation photovoltaic technologies, it will be necessary to scale up production. This review article explores the advancements in several scalable perovskite deposition techniques, including recent developments in the fabrication of high-quality perovskite film, their stabilities and commercialization status. Several scalable deposition techniques are discussed, including user-friendly solution-techniques (spin coating, slot die coating, etc.), vapour-assisted deposition approaches in the laboratory and full-scale commercial applications. The aforementioned deposition techniques have advantages compared to deposition techniques based on cost, effective mask-less patterning and unparalleled-design freedom. Other potential advantages include optimal use of materials, scalability, contactless deposition in high-resolution and a rapid transformation from small laboratory-scale work to large industrial-scale roll-to-roll production. Most recent technological advancements and structural developments relate to long-term thermal stability and moisture resistance. Many of the developments are still in the evolving field of lab-scale devices. The improvement roadmap and commercialization aspects of PSC manufacture involve two significant milestones: bridging the gap between the performance characteristics of small-scale and large-scale devices and the scalable printing techniques for all the layers in the device.
Abstract.
Roy A, Mallick TK, Tahir AA (2022). An optimal climate-adaptable hydrogel-filled smart window for the energy-saving built environment.
Journal of Materials Chemistry C,
10(41), 15474-15482.
Abstract:
An optimal climate-adaptable hydrogel-filled smart window for the energy-saving built environment
It is highly desirable to secure the net-zero targets by employing sustainable building materials that can store and release their energy depending on the weather.
Abstract.
Roy A, Mohamed MJS, Gondal MA, Mallick TK, Tahir AA, Sundaram S (2022). Co-sensitization effect of N719 dye with Cu doped CdS colloidal nanoparticles for dye sensitized solar cells. Inorganic Chemistry Communications, 148, 110298-110298.
Bhandari S, Ghosh A, Roy A, Mallick TK, Sundaram S (2022). Compelling temperature behaviour of carbon-perovskite solar cell for fenestration at various climates. Chemical Engineering Journal Advances, 10
Roy A, Ullah H, Ghosh A, Mallick TK, Tahir AA (2022). Corrigendum to “Smart glazing thermal comfort improvement through near-infrared shielding paraffin incorporated SnO2-Al2O3 composite” [Constr. Build. Mater. 331 (2022) 127319]. Construction and Building Materials, 341
Velusamy S, Roy A, Sundaram S, Mallick TK (2022). Employing CdS nanoparticles as an adsorbent for the removal of different dosages of hexavalent Cr (VI) from aqueous solution.
Materials Letters,
311Abstract:
Employing CdS nanoparticles as an adsorbent for the removal of different dosages of hexavalent Cr (VI) from aqueous solution
The discharge of chromium effluent from various industries becomes a severe threat to the environment, creating a risk to human health and environmental aspects. In this study, Cr (VI) removal from aqueous solution by adsorption was investigated using commercially available CdS at different concentrations to consider an industrial-level large-scale application. Adsorption efficiency depends on a few parameters: pH, adsorbent dosage, initial concentration of Cr (VI) solution, temperature and contact time. For understanding the adsorption process, adsorption kinetics and adsorption Isotherm studies were applied to check the best fit mechanism of the adsorption process. The pseudo-second-order kinetics followed by the Langmuir adsorption isotherm model is the most fitted model for removing chromium using CdS. This study signifies another toxic compound, CdS, that can effectively convert Cr (VI) toxic to Cr (III) non-toxic state.
Abstract.
Alruwaili M, Roy A, Nundy S, Tahir AA (2022). Fabrication of TiVO<sub>4</sub> photoelectrode for photoelectrochemical application.
RSC Advances,
12(53), 34640-34651.
Abstract:
Fabrication of TiVO4 photoelectrode for photoelectrochemical application
TiVO4 photoanode was prepared using the spray pyrolysis technique and further employed for photoelectrochemical water splitting to produce hydrogen.
Abstract.
Sheikh MS, Ghosh A, Roy A, Bhandari S, Sundaram S, Mallick TK, Ghosh H, Sinha TP (2022). High Open-Circuit Voltage in Double Perovskite Oxide A(2)NdSbO(6) (A = Ba, Sr) Photoanode-Based Dye-Sensitized Solar Cells.
JOURNAL OF ELECTRONIC MATERIALS,
51(8), 4281-4287.
Author URL.
Yadav A, Kumar P, Rawat D, Garg S, Mukherjee P, Farooqi F, Roy A, Sundaram S, Sharma RS, Mishra V, et al (2022). Microbial fuel cells for mineralization and decolorization of azo dyes: Recent advances in design and materials.
Sci Total Environ,
826Abstract:
Microbial fuel cells for mineralization and decolorization of azo dyes: Recent advances in design and materials.
Microbial fuel cells (MFCs) exhibit tremendous potential in the sustainable management of dye wastewater via degrading azo dyes while generating electricity. The past decade has witnessed advances in MFC configurations and materials; however, comprehensive analyses of design and material and its association with dye degradation and electricity generation are required for their industrial application. MFC models with high efficiency of dye decolorization (96-100%) and a wide variation in power generation (29.4-940 mW/m2) have been reported. However, only 28 out of 104 studies analyzed dye mineralization - a prerequisite to obviate dye toxicity. Consequently, the current review aims to provide an in-depth analysis of MFCs potential in dye degradation and mineralization and evaluates materials and designs as crucial factors. Also, structural and operation parameters critical to large-scale applicability and complete mineralization of azo dye were evaluated. Choice of materials, i.e. bacteria, anode, cathode, cathode catalyst, membrane, and substrate and their effects on power density and dye decolorization efficiency presented in review will help in economic feasibility and MFCs scalability to develop a self-sustainable solution for treating azo dye wastewater.
Abstract.
Author URL.
Bhandari S, Roy A, Mallick TK, Sundaram S (2022). Morphology modulated brookite TiO2 and BaSnO3 as alternative electron transport materials for enhanced performance of carbon perovskite solar cells. Chemical Engineering Journal, 446, 137378-137378.
Khalid M, Roy A, Bhandari S, Selvaraj P, Sundaram S, Mallick TK (2022). Opportunities of copper addition in CH3NH3PbI3 perovskite and their photovoltaic performance evaluation. Journal of Alloys and Compounds, 895, 162626-162626.
Rokade AV, Jadhav YA, Jathar S, Rahane S, Barma S, Rahane GK, Thawarkar S, Vairale P, Punde A, Shah S, et al (2022). Realization of Electrochemically Grown α-Fe<inf>2</inf>O<inf>3</inf> Thin Films for Photoelectrochemical Water Splitting Application.
Engineered Science,
17, 242-255.
Abstract:
Realization of Electrochemically Grown α-Fe2O3 Thin Films for Photoelectrochemical Water Splitting Application
Hematite ferric oxide (α-Fe2O3) based photoanode has emerged as a potential candidate for water splitting application due to its high absorption coefficient in the visible region and favorable band alignment. In the present work, α-Fe2O3 thin film photoanodes were fabricated using a cost-effective and straightforward electrodeposition technique. The crystal structure, phase purity, elemental composition, and formation of α-Fe2O3 were confirmed by X-ray diffraction (XRD), photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, energy-dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). The bandgap calculated from the absorption spectrum from UV-visible analysis of α-Fe2O3 exhibited a significant absorption in the visible region. The α-Fe2O3 photoanodes were further characterized for their photoelectrochemical (PEC) properties along with electrochemical impedance spectroscopy (EIS) analysis. Furthermore, XRD, SEM, and Fourier transform infrared (FTIR) spectroscopy investigations were performed after photoelectrochemical measurement to ensure the stability of photoanodes. Also, the prepared photoanode was highly stable against a large range of pH conditions, and no photobleaching was observed for up to 30 min. Furthermore, a significant enhancement in the photocurrent conversion efficiency with an optimum film thickness was observed upon light illumination. A maximum photon conversion efficiency of 1.44 % was obtained with a photocurrent density of 6.25 mA/cm2 for 1 V vs. saturated calomel electrode (SCE) under the simulated solar light.
Abstract.
Roy A, Ghosh A, Mallick TK, Tahir AA (2022). Smart glazing thermal comfort improvement through near-infrared shielding paraffin incorporated SnO<inf>2</inf>-Al<inf>2</inf>O<inf>3</inf> composite.
Construction and Building Materials,
331Abstract:
Smart glazing thermal comfort improvement through near-infrared shielding paraffin incorporated SnO2-Al2O3 composite
Building's energy conservation signifies a lowering in building energy consumption without sacrificing thermal comfort. Window glazing is the most suitable approach to the built environment that can be controlled through its sustainable development for global energy consumption. In this work, for the first time, paraffin incorporated SnO2-Al2O3 composite coating is developed on a 5 cm × 5 cm glass using a screen-printing method, which signifies an intelligent cooling behaviour for a comfortable indoor environment irrespective of their emplacement. The composite energy-saving properties exhibit less transmission of infra-red light while keeping high visible light transmittance behaviour resulting superior heat-shielding performance. The composite coated glass's average indoor temperature profile remains at ∼30 °C when the outside temperature reaches a maximum of 45 °C during outdoor testing. While the same composite film is set inside, the indoor average temperature maintains ∼30 °C, whereas outside temperature reaches a maximum of 80 °C. The distinct temperature profile for composite coated glass indicates high transparency of 80% throughout the experiment. Interestingly paraffin has been incorporated into the composite, offering no leakage, translucent characteristics, and limited water ingress. In comparison, non-coated glass is failed to provide them with a comfortable, stable indoor temperature. We believe this study envisages the recent technological innovations combined with phase change material and transparent infrared absorber together as a composite for window glass for warmer climates, which further leads to significant energy savings compared with plain glass.
Abstract.
Roy A, Ullah H, Alzahrani M, Ghosh A, Mallick TK, Tahir AA (2022). Synergistic effect of paraffin incorporated In2O3:ZnO multi-fold composite smart glazing for the self-cleaning and energy-saving built environment.
ACS Sustainable Chemistry and Engineering,
10, 6609-6621.
Abstract:
Synergistic effect of paraffin incorporated In2O3:ZnO multi-fold composite smart glazing for the self-cleaning and energy-saving built environment
The thermal performance of window glazing requires improvement for a sustainable built environment at an acceptable cost. The current work demonstrates a multifold smart composite consisting of an optimized In2O3/ZnO–polymethyl methacrylate–paraffin composite to reduce heat exchange through the combined self-cleaning and energy-saving envelope of the smart built environment. This work has attempted to develop a smart composite coating that combines photosensitive metal oxide and phase change materials and investigate their thermal comfort performance as a glazed window. It is observed that the In2O3/ZnO (5 wt %) multifold composite film experienced better transmittance and thermal performance compared to its other wt % composite samples. Moreover, the multifold composite-coated glass integrated into a prototype glazed window was further investigated for its thermal performance, where a steady average indoor temperature of ∼30 °C was achieved when the outside temperature reached ∼55 °C, while maintaining good visibility. Interestingly, the transparency reached ∼86% at 60 °C and exhibited a hydrophobic water contact angle (WCA) of ∼138°. In contrast, a similar film exhibits ∼64% transparency at 22 °C, where the WCA becomes moderately hydrophilic (∼68°). Temperature dependency on transparency and wettability properties was examined for up to 60 cycles, resulting in excellent indoor thermal comfort. In addition, a thermal simulation study was executed for the smart multifold glazing composite. Moreover, this study offers dynamic glazing development options for energy saving in the smart built environment.
Abstract.
Ghosh P, Roy A, Mukhopadhyay S, Narjinary M, Sundaram S, Sen S, Devi PS (2021). A New Functional Composite for Photovoltaic and Sensor Applications. Advanced Electronic Materials, 7(3), 2000785-2000785.
Velusamy S, Roy A, Sundaram S, Mallick TK (2021). A Review on Heavy Metal Ions and Containing Dyes Removal Through Graphene Oxide-Based Adsorption Strategies for Textile Wastewater Treatment. The Chemical Record
Roy A, Ghosh S, Ghosh K, Ghosh S (2021). An Unsupervised Normalization Algorithm for Noisy Text: a Case Study for Information Retrieval and Stance Detection.
Journal of Data and Information Quality,
13(3).
Abstract:
An Unsupervised Normalization Algorithm for Noisy Text: a Case Study for Information Retrieval and Stance Detection
A large fraction of textual data available today contains various types of "noise,"such as OCR noise in digitized documents, noise due to informal writing style of users on microblogging sites, and so on. To enable tasks such as search/retrieval and classification over all the available data, we need robust algorithms for text normalization, i.e. for cleaning different kinds of noise in the text. There have been several efforts towards cleaning or normalizing noisy text; however, many of the existing text normalization methods are supervised and require language-dependent resources or large amounts of training data that is difficult to obtain. We propose an unsupervised algorithm for text normalization that does not need any training data/human intervention. The proposed algorithm is applicable to text over different languages and can handle both machine-generated and human-generated noise. Experiments over several standard datasets show that text normalization through the proposed algorithm enables better retrieval and stance detection, as compared to that using several baseline text normalization methods.
Abstract.
Velusamy S, Roy A, Sundaram S, Mallick TK (2021). Cover Picture: a Review on Heavy Metal Ions and Containing Dyes Removal Through Graphene Oxide‐Based Adsorption Strategies for Textile Wastewater Treatment (Chem. Rec. 7/2021). The Chemical Record, 21(7), 1569-1569.
Roy A, Sundaram S, Mallick TK (2021). Cu<inf>2</inf>ZnSnS<inf>4</inf>, a Fascinating Counter Electrode for TiO<inf>2</inf>-Free Dye-Sensitized Solar Cells.
ChemistrySelect,
6(7), 1541-1547.
Abstract:
Cu2ZnSnS4, a Fascinating Counter Electrode for TiO2-Free Dye-Sensitized Solar Cells
Since innovation, different dye-sensitized solar cells (DSSCs) have endeavored with additional components to escalate the efficiency, cost-effectiveness and long-term stability. Various approaches have been executed to reduce the amount of costly platinum (Pt) used in DSSCs and/or to explore cheaper alternatives to Pt. In this work, cheaper elements based quaternary chalcogenide alloy; Cu2ZnSnS4 (CZTS) has been projected as a prominent counter electrode (CE) candidate to Pt in DSSCs. The CZTS thin film has been developed by an in-situ synthesis employing a hydrothermal technique and further evaluating various physicochemical characterization. Our results manifest that using the CZTS CE, a power conversion efficiency (PCE) of 4.3 % was exhibited for TiO2 based photoanode. The highest PCE of 6.5 % was achieved for BaSnO3 based photoanode, a promising alternative oxide to TiO2 photoanode. This work further signifies a unique combination of newly developed BaSnO3(BSO)-CZTS DSSCs, could be a promising competitor to TiO2-Pt DSSCs.
Abstract.
Alzahrani M, Roy A, Shanks K, Sundaram S, Mallick TK (2021). Graphene as a pre-illumination cooling approach for a concentrator photovoltaic (CPV) system. Solar Energy Materials and Solar Cells, 222, 110922-110922.
Chanchangi YN, Roy A, Ghosh A, Sundaram S, Mallick TK (2021). In-situ assessment of photovoltaic soiling mitigation techniques in northern Nigeria. Energy Conversion and Management, 244, 114442-114442.
Wittler N, Roy F, Pack K, Werninghaus M, Roy AS, Egger DJ, Filipp S, Wilhelm FK, Machnes S (2021). Integrated Tool Set for Control, Calibration, and Characterization of Quantum Devices Applied to Superconducting Qubits.
Physical Review Applied,
15(3).
Abstract:
Integrated Tool Set for Control, Calibration, and Characterization of Quantum Devices Applied to Superconducting Qubits
Efforts to scale-up quantum computation have reached a point where the principal limiting factor is not the number of qubits, but the entangling gate infidelity. However, the highly detailed system characterization required to understand the underlying error sources is an arduous process and impractical with increasing chip size. Open-loop optimal control techniques allow for the improvement of gates but are limited by the models they are based on. To rectify the situation, we provide an integrated open-source tool set for control, calibration, and characterization (C3), capable of open-loop pulse optimization, model-free calibration, model fitting, and refinement. We present a methodology to combine these tools to find a quantitatively accurate system model, high-fidelity gates, and an approximate error budget, all based on a high-performance, feature-rich simulator. We illustrate our methods using simulated fixed-frequency superconducting qubits for which we learn model parameters with less than 1% error and derive a coherence-limited cross-resonance gate that achieves 99.6% fidelity without the need for calibration.
Abstract.
Khalid M, Roy A, Bhandari S, Sundaram S, Mallick TK (2021). Integrating Concentrated Optics for Ambient Perovskite Solar Cells.
ENERGIES,
14(9).
Author URL.
Alzahrani MM, Roy A, Sundaram S, Mallick TK (2021). Investigation of Thermal Stress Arising in a Graphene Neutral Density Filter for Concentrated Photovoltaic System.
ENERGIES,
14(12).
Author URL.
Sheikh MS, Roy A, Dutta A, Sundaram S, Mallick TK, Sinha TP (2021). Nanostructured perovskite oxides for dye-sensitized solar cells.
JOURNAL OF PHYSICS D-APPLIED PHYSICS,
54(49).
Author URL.
Das PP, Roy A, Devi PS, Lee Y (2021). Solution processed Al-doped ZnO and its performance in dye sensitized solar cells.
Current Applied Physics,
30, 69-76.
Abstract:
Solution processed Al-doped ZnO and its performance in dye sensitized solar cells
Al-doped ZnO rods of nanometer to sub-micrometer size range have been successfully synthesized by a simple yet cost-effective solution processed sonochemical technique. Systematic XRD analysis established the solid solubility limit for Al in the ZnO lattice to be ca. 3 mol% at an elevated annealing temperature of 800 °C. The secondary ZnAl2O4 phase appears with increasing dopant concentrations and at lower annealing temperatures. Significant variations in the optoelectronic properties are induced by modifications in the surface defects of ZnO rods as a result of Al doping. As a consequence, an improved fill factor (FF) of 74.78 and 75.76% with a conversion efficiency (η) of 1.59 and 1.79% have been achieved for the fabricated DSSC devices made of the 800 °C annealed ZnO rods doped by 1 and 3 mol% Al, respectively.
Abstract.
Sinhababu M, Roy A, Kumar N, Dutta M, Sundaram S, Karazhanov S, Udayabhanu G (2021). Surface Treatment of Industrial-Grade Magnetite Particles for Enhanced Thermal Stability and Mitigating Paint Contaminants.
Nanomaterials,
11(9), 2299-2299.
Abstract:
Surface Treatment of Industrial-Grade Magnetite Particles for Enhanced Thermal Stability and Mitigating Paint Contaminants
Pigments can retain their color for many centuries and can withstand the effects of light and weather. The paint industry suffers from issues like aggressive moisture, corrosion, and further environmental contamination of the pigment materials. Low-cost, long-lasting, and large-scale pigments are highly desirable to protect against the challenges of contamination that exist in the paint industry. This exploratory study reinforces the color and thermal stability of industrial-grade (IG) magnetite (Fe3O4). IG Fe3O4 pigments were further considered for surface treatment with sodium hexametaphosphate (SHMP). This metaphosphate hexamer sequestrant provides good dispersion ability and a high surface energy giving thermal and dust protection to the pigment. Various physicochemical characterizations were employed to understand the effectiveness of this treatment across various temperatures (180–300 °C). The X-ray diffraction, Raman, and X-ray photoelectron spectroscopy techniques signify that the SHMP-treated Fe3O4 acquired magnetite phase stability up to 300 °C. In addition, the delta-E color difference method was also adopted to measure the effective pigment properties, where the delta-E value significantly decreased from 8.77 to 0.84 once treated with SHMP at 300 °C. The distinct color retention at 300 °C and the improved dispersion properties of surface-treated Fe3O4 positions this pigment as a robust candidate for high-temperature paint and coating applications. This study further encompasses an effort to design low-cost, large-scale, and thermally stable pigments that can protect against UV-rays, dust, corrosion, and other color contaminants that are endured by building paints.
Abstract.
Sadhukhan P, Roy A, Sengupta P, Das S, Mallick TK, Nazeeruddin MK, Sundaram S (2021). The emergence of concentrator photovoltaics for perovskite solar cells.
APPLIED PHYSICS REVIEWS,
8(4).
Author URL.
Wang S, Roy A, Komvopoulos K (2021). Thermal stability and diffusion characteristics of ultrathin amorphous carbon films grown on crystalline and nitrogenated silicon substrates by filtered cathodic vacuum arc deposition.
Scientific Reports,
11(1).
Abstract:
Thermal stability and diffusion characteristics of ultrathin amorphous carbon films grown on crystalline and nitrogenated silicon substrates by filtered cathodic vacuum arc deposition
Amorphous carbon (a-C) films are widely used as protective overcoats in many technology sectors, principally due to their excellent thermophysical properties and chemical inertness. The growth and thermal stability of sub-5-nm-thick a-C films synthesized by filtered cathodic vacuum arc on pure (crystalline) and nitrogenated (amorphous) silicon substrate surfaces were investigated in this study. Samples of a-C/Si and a-C/SiNx/Si stacks were thermally annealed for various durations and subsequently characterized by high-resolution transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS). The TEM images confirmed the continuity and uniformity of the a-C films and the 5-nm-thick SiNx underlayer formed by silicon nitrogenation using radio-frequency sputtering. The EELS analysis of cross-sectional samples revealed the thermal stability of the a-C films and the efficacy of the SiNx underlayer to prevent carbon migration into the silicon substrate, even after prolonged heating. The obtained results provide insight into the important attributes of an underlayer in heated multilayered media for preventing elemental intermixing with the substrate, while preserving the structural stability of the a-C film at the stack surface. An important contribution of this investigation is the establishment of an experimental framework for accurately assessing the thermal stability and elemental diffusion in layered microstructures exposed to elevated temperatures.
Abstract.
Roy A, Sundaram S, Mallick T, ghosh P, Sujatha Devi P (2020). Efficient carbon counter electrodes for BaSnO3-based dye-sensitized solar cells. Materials Today: Proceedings
Bhandari S, Roy A, Mallick T, Sundaram S (2020). Impact of different light induced effect on organic hole-transporting layer in perovskite solar cells. Materials Letters
Bhandari S, Roy A, Ghosh A, Mallick T, Sundaram S (2020). Perceiving the Temperature Coefficients of Carbon-based Perovskite Solar Cells. Sustainable Energy and Fuels
Roy A, Ghosh A, Bhandari S, Sundaram S, Mallick T (2020). Perovskite Solar Cells for BIPV Application: a Review. Buildings, 10
Roy A, Ghosh A, Bhandari S, Sundaram S, Mallick TK (2020). Realization of Poly(methyl methacrylate)-Encapsulated Solution-Processed Carbon-Based Solar Cells: an Emerging Candidate for Buildings’ Comfort. Industrial & Engineering Chemistry Research, 59(23), 11063-11071.
Roy A, Velusamy S, Mallick TK, Sundaram S (2020). Synergistic effect of nanoflower-like CdS for removal of highly toxic aqueous Cr(VI). Materials Letters, 270, 127734-127734.
Roy A, Ghosh A, Bhandari S, Selvaraj P, Sundaram S, Mallick TK (2019). Color Comfort Evaluation of Dye-Sensitized Solar Cell (DSSC) Based Building-Integrated Photovoltaic (BIPV) Glazing after 2 Years of Ambient Exposure. The Journal of Physical Chemistry C, 123(39), 23834-23837.
Selvaraj P, Roy A, Ullah H, Sujatha Devi P, Tahir AA, Mallick TK, Sundaram S (2019). Soft-template synthesis of high surface area mesoporous titanium dioxide for dye-sensitized solar cells.
International Journal of Energy Research,
43(1), 523-534.
Abstract:
Soft-template synthesis of high surface area mesoporous titanium dioxide for dye-sensitized solar cells
In the present work, 10 to 14 nm titania nanoparticles with high-packing density are synthesized by the soft-template method using a range of cationic surfactants including cetyl trimethylammonium bromide (CTAB), Sodium dodecyl sulfate (SDS), and dodecyl trimethylammonium bromide (DTAB). The synthesized nanoparticles are used as a photoanode material in dye solar cells. Density functional theory (DFT) simulations reproduce our experimental results of charge transfer and strong interaction between the TiO2 and N719. N719-TiO2 complex establishes strong electrostatic bonding through H of the dye with the O of TiO2 surface. Solar cell efficiency of 6.08% with 12.63 mA/cm2, 793 mV, and 48.5% for short circuit current density, open circuit voltage, and fill factor, respectively, are obtained under 1 sun illumination for the dye-sensitized solar cell (DSSC) using a film of mesoporous TiO2 synthesized from the SDS surfactant. On the other hand, the 21 nm commercial TiO2 powder (P25) device results in 4.60% efficiency under similar conditions. Electrochemical impedance spectroscopic studies show that the SDS device has lesser charge transport resistance than the other devices because of its higher surface area, packing density, and dye loading capacity. Our results show that employing high packing density-based TiO2 nanoparticles represents a commercially viable approach for highly beneficial photoanode development for future DSSC applications.
Abstract.
Roy A, Das PP, Selvaraj P, Devi PS, Sundaram S (2019). Template free synthesis of CdSnO<inf>3</inf> micro-cuboids for dye sensitized solar cells.
Journal of Photochemistry and Photobiology A: Chemistry,
380Abstract:
Template free synthesis of CdSnO3 micro-cuboids for dye sensitized solar cells
Mesoporous transparent conducting oxide, CdSnO3 has been synthesized using ultrasonication assisted co-precipitation method. Rather employing any template or structure directing agent, the co-precipitation effect of sodium hydroxide and citric acid were able to form cuboid shaped CdSnO3 during the sonochemical treatment as investigated by a systematic X-ray diffraction and field emission scanning electron microscopy studies. An optimum 3:1 molar concentration of NaOH and citric acid leads to form cuboidal structure of CdSnO3 on calcined at 700 °C. Further calcination at 800 °C converted cuboids to nanoparticles. Comparative studies have been carried out between the cuboid and particle morphology to understand the physico-chemical properties related to the morphology using various characterization techniques. Further, the CTO cuboids and the decomposed nanoparticles have been tested as photoanode for dye sensitized solar cell applications. The cuboid based photoanode exhibited an enhanced efficiency of 3.23% with a VOC of 0.72 V than its decomposed nanoparticle which exhibited a lower efficiency of 2.67%. The electrochemical impedance and incident photon to electron conversion efficiency results also support enhanced performance of cuboid based device than particle. The overall results show the advantage of cuboidal CdSnO3 in rapid electron injection and higher light reflection leading to improved current density of the DSSC device than the decomposed nanoparticle form. The results establish the application of less explored CdSnO3 as a photoanode in DSSCs application.
Abstract.
Roy A, Devi PS, Karazhanov S, Mamedov D, Mallick TK, Sundaram S (2018). A review on applications of Cu<inf>2</inf>ZnSnS<inf>4</inf> as alternative counter electrodes in dye-sensitized solar cells.
AIP Advances,
8(7).
Abstract:
A review on applications of Cu2ZnSnS4 as alternative counter electrodes in dye-sensitized solar cells
A contribution of counter electrode (CE) emphasis a great impact towards enhancement of a dye-sensitized solar cell's (DSSC) performance and Pt based CE sets a significant benchmark in this field. Owing to cost effective noble metal, less abundance and industrial large scale application purpose, an effective replacement for Pt is highly demanded. There are several approaches to improve the performance of a CE for enhancing the power conversion efficiency with a less costly and facile device. To address this issue, reasonable efforts execute to find out suitable replacement of Pt is becoming a challenge by keeping the same electrochemical properties of Pt in a cheaper and eco-friendlier manner. With this, cheaper element based quaternary chalcogenide, Cu2ZnSnS4 (CZTS) becomes a prominent alternative to Pt and used as a successful CE in DSSC also. This review presents brief discussion about the basic properties of CZTS including its synthesis strategy, physicochemical properties and morphology execution and ultimate application as an alternative Pt free CE for a low cost based enhanced DSSC device. It is therefore, imperative for engineering of CZTS material and optimization of the fabrication method for the improvement of DSSC performance.
Abstract.
Roy A, Sharma A, Gupta A, Meena V, Harsha AP (2018). Enhanced tribological properties of aluminium using laser-assisted tungsten coating.
World Review of Science, Technology and Sustainable Development,
14(2-3), 102-118.
Abstract:
Enhanced tribological properties of aluminium using laser-assisted tungsten coating
Aluminium (Al) suffers from poor wear and scratch resistance and also low surface hardness. To overcome this, the authors fabricated a ~200 μm coating of fine tungsten (W) powder on Al using laser surface alloying (LSA) with laser power and scanning speed varying from 400–800 W and 800–1,200 mm/min respectively. Material characterisation in the form of SEM and XRD, undertaken on the LSA samples, revealed novel microstructures including formation of intermetallic phases Al4W, Al12W that exhibit substantially higher hardness. Scratch hardness measurements further consolidated that surface hardness of coated samples was more than three times as compared to bulk aluminium. Scratch testing at normal loads of 50–150 N, scratch speed of 30 mm/min, demonstrated a stable friction coefficient of 0.6 and higher coating adhesive strength. When applied to automobile components and aerospace products, the micro-coated LSA samples can provide far better alternatives to the current industrial grade of aluminium from the tribology point of view.
Abstract.
Harsha AP, Roy A, Sharma A, Gupta A, Meena V (2018). Enhanced tribological properties of aluminium using laser-assisted tungsten coating. World Review of Science Technology and Sustainable Development, 14(2/3).
Das PP, Roy A, Agarkar S, Devi PS (2018). Hydrothermally synthesized fluorescent Zn2SnO4 nanoparticles for dye sensitized solar cells. Dyes and Pigments, 154, 303-313.
Sundaram S, Roy A, Selvaraj P, Parukuttyamma SD (2018). Morphology tuned BaSnO 3 active layer for ambient perovskite solar cells. Materials Letters
Das PP, Pramanik S, Chatterjee S, Roy A, Saha A, Devi PS, Kumar GS (2018). Multiband Fluorescent Graphitic Carbon Nanoparticles from Queen of Oils. ACS Sustainable Chemistry & Engineering, 6(8), 10127-10139.
Bhattacharya M, Sivasubramani S, Roy A (2018). Multiobjective placement and sizing of distributed generations in distribution system using global criterion method.
International Transactions on Electrical Energy Systems,
28(1).
Abstract:
Multiobjective placement and sizing of distributed generations in distribution system using global criterion method
This paper presents a multiobjective method for obtaining optimal size and site of distributed generation (DG), to reduce loss, and DG investment cost while improving the voltage profile in primary distribution networks. To solve the multiobjective problem, a classical technique known as global criterion method is implemented to form a novel objective function equation, which is custom-built for a distribution system. The application of the global criterion method is explained using a DG that is capable of injecting real power, ie, unity power factor DG, and then extended to DGs capable of injecting reactive power. The method is validated for 2 distribution systems. Results show that the proposed method satisfies the individual objectives simultaneously. The proposed method is also compared with existing methods to exhibit its effectiveness.
Abstract.
Roy A, Das PP, Selvaraj P, Sundaram S, Sujatha Devi P (2018). Perforated BaSnO3 Nanorods Exhibiting Enhanced Efficiency in Dye Sensitized Solar Cells. ACS Sustainable Chemistry and Engineering, 6, 3299-3310.
Adedokun O, Roy A, Awodugba AO, Devi PS (2017). Fluorescent carbon nanoparticles from Citrus sinensis as efficient sorbents for pollutant dyes.
LUMINESCENCE,
32(1), 62-70.
Author URL.
Nag P, Das PP, Roy A, Devi PS (2017). Iron antimonate quantum dots exhibiting tunable visible light emission. New Journal of Chemistry, 41(4), 1436-1446.
Roy A, Das PP, Tathavadekar M, Das S, Devi PS (2017). Performance of colloidal CdS sensitized solar cells with ZnO nanorods/nanoparticles.
BEILSTEIN JOURNAL OF NANOTECHNOLOGY,
8, 210-221.
Author URL.
Das PP, Roy A, Tathavadekar M, Devi PS (2017). Photovoltaic and photocatalytic performance of electrospun Zn2SnO4 hollow fibers. Applied Catalysis B Environmental, 203, 692-703.
Dey R, Roy A, Chakraborty T, Ghosh S (2017). Sleeping beauties in Computer Science: characterization and early identification.
Scientometrics,
113(3), 1645-1663.
Abstract:
Sleeping beauties in Computer Science: characterization and early identification
While a large majority of scientific publications get most of their citations within the initial few years after publication, there is an interesting number of papers—termed as sleeping beauties—which do not get much cited for several years after being published, but then suddenly start getting cited heavily. In this work, we focus on sleeping beauties (SBs) in the domain of Computer Science. We identify more than 5,000 sleeping beauties in Computer Science, and characterise them based on their sub-field and their citation profile after awakening. We also reveal some interesting factors which led to their awakening long after publication. Furthermore, we also propose a methodology for early identification of sleeping beauties, and develop a machine learning-based classification approach that attempts to classify publications based on whether they are likely to be SBs. The classifier achieves a precision of 0.73 and a recall of 0.45 in identifying SBs immediately after their year of publications, and the performance significantly improves with time. To our knowledge, this is the first study on sleeping beauties in Computer Science.
Abstract.
Das PP, Roy A, Das S, Devi PS (2016). Enhanced stability of Zn2SnO4 with N719, N3 and eosin Y dye molecules for DSSC application.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS,
18(3), 1429-1438.
Author URL.
Vora HD, Rajamure RS, Roy A, Srinivasan SG, Sundararajan G, Banerjee R, Dahotre NB (2016). Laser Assisted Additively Manufactured Transition Metal Coating on Aluminum.
JOM,
68(7), 1819-1829.
Abstract:
Laser Assisted Additively Manufactured Transition Metal Coating on Aluminum
Various physical and chemical properties of surface and subsurface regions of Al can be improved by the formation of transition metal intermetallic phases (AlxTMy) via coating of the transition metal (TM). The lower equilibrium solid solubility of TM in Al (
Abstract.
Roy A, Chatterjee S, Pramanik S, Devi PS, Kumar GS (2016). Selective detection of Escherichia coli DNA using fluorescent carbon spindles.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS,
18(17), 12270-12277.
Author URL.
Das PP, Roy A, Devi PS (2016). Zn2SnO4 as an Alternative Photoanode for Dye Sensitized Solar Cells: Current Status and Future Scope. Transactions of the Indian Ceramic Society, 75(3), 147-154.
Mahto TK, Roy A, Sahoo B, Sahu SK (2015). Citric Acid Fuctionalized Magnetic Ferrite Nanoparticles for Photocatalytic Degradation of Azo Dye.
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY,
15(1), 273-280.
Author URL.
Das S, Nayak GC, Sahu SK, Routray PC, Roy AK, Baskey H (2015). Microwave absorption properties of double-layer composites using CoZn/NiZn/MnZn-ferrite and titanium dioxide.
Journal of Magnetism and Magnetic Materials,
377, 111-116.
Abstract:
Microwave absorption properties of double-layer composites using CoZn/NiZn/MnZn-ferrite and titanium dioxide
Zinc substituted ferrite powders Me0.5Zn0.5Fe2O4 (Me=Co, Mn and Ni) were prepared by the sol-gel auto-combustion method. The present study highlights development of Single layer and double layer composite microwave absorbing materials using Ferrites, Titanium dioxide and Epoxy matrix. Moreover microwave absorption property, i.e. reflection loss evaluated at X-band frequency. XRD analysis of the filler particles were carried out to evaluate crystal structure, average crystallite diameter. Morphology of the filler particles were studied with FESEM. Hysteresis behavior of the ferrites samples were studied with Vibrating Sample Magnetometer. The most important parameter governing the absorption properties of microwave absorbers i.e. permittivity and permeability studied in a vector network analyzer. Measured reflection loss value of single-layer NiZn-ferrite based microwave absorber reaches -11.2 dB at 12.05 GHz. Whereas, reflection loss value of double-layer CoZn-ferrite/ TiO2 based microwave absorber reaches -24.3 dB at 12.02 GHz. The result shows that microwave absorption property and bandwidth of absorption of double-layer microwave absorber was found to improve comparison to single layer.
Abstract.
Das S, Nayak GC, Sahu SK, Routray PC, Roy AK, Baskey H (2015). Titania-Coated Magnetite and Ni-Ferrite Nanocomposite-Based RADAR Absorbing Materials for Camouflaging Application.
Polymer - Plastics Technology and Engineering,
54(14), 1483-1493.
Abstract:
Titania-Coated Magnetite and Ni-Ferrite Nanocomposite-Based RADAR Absorbing Materials for Camouflaging Application
A novel core–shell-structured nanocomposite material based on titanium dioxide-coated magnetite and Ni-ferrite has been prepared for RADAR absorbing application in a X-band region. The coating of magnetic particles with TiO2 was carried out by in situ hydrolysis of titanium tetrabutoxide, and the composite absorber sheets were prepared with epoxy resin. The morphological characterization of the magnetic particles was studied with field emission scanning electron microscope, transmission electron microscope, X-ray diffraction, and vibrating sample magnetometer analysis techniques. The measurement results confirmed the coating of magnetic particles with TiO2 and reduction of the magnetization of magnetite and Ni-ferrite nanoparticles compared with the uncoated ferrite nanoparticles. Distribution of particle inside the matrix was studied with scanning electron microscope. Microwave absorption study in X-band (8–12 GHz) region was carried out with vector network analyzer. Results showed reflection loss values of −26.5 db at 9.08 GHz for the magnetite coated with titanium dioxide/conducting carbon black containing sample which increased to −45.7 db at 9.13 GHz for the Ni-ferrite coated with TiO2/conducting carbon black formulation. It was observed that coating of magnetic particles resulted in the improvement in the microwave absorption.
Abstract.
Das S, Nayak GC, Sahu SK, Routray PC, Roy AK, Baskey H (2014). Microwave Absorption Properties of Double-Layer RADAR Absorbing Materials Based on Doped Barium Hexaferrite/TiO<inf>2</inf>/Conducting Carbon Black.
Journal of Engineering (United Kingdom),
2014Abstract:
Microwave Absorption Properties of Double-Layer RADAR Absorbing Materials Based on Doped Barium Hexaferrite/TiO2/Conducting Carbon Black
In this report, we demonstrate microwave absorption properties of barium hexaferrite, doped barium hexaferrite, titanium dioxide and conducting carbon black based RADAR absorbing material for stealth application. Double-layer absorbers are prepared with a top layer consisting of 30% hexaferrite and 10% titanium dioxide while the bottom layer composed of 30% hexaferrite and 10% conducting carbon black, embedded in chloroprene matrix. The top and bottom layers are prepared as impedance matching layer and conducting layer, respectively, with a total thickness of 2 mm. Microwave absorption properties of all the composites were analyzed in X-band region. Maximum reflection loss of -32 dB at 10.64 GHz was observed for barium hexaferrite based double-layer absorber whereas for doped barium hexaferrite based absorber the reflection loss was found to be -29.56 dB at 11.7 GHz. A consistence reflection loss value (>-24 dB) was observed for doped barium hexaferrite based RADAR absorbing materials within the entire bandwidth.
Abstract.
Chapters
Velusamy S, Roy A, Sundaram S, Mallick TK (2022). Concern for heavy metal ion water pollution. In (Ed) Contaminants of Emerging Concerns and Reigning Removal Technologies, 257-284.
Conferences
Basu M, Roy A, Ghosh K, Bandyopadhyay S, Ghosh S (2017). A novel word embedding based stemming approach for microblog retrieval during disasters.
Abstract:
A novel word embedding based stemming approach for microblog retrieval during disasters
Abstract.
Basu M, Roy A, Ghosh K, Bandyopadhyay S, Ghosh S (2017). Microblog retrieval in a disaster situation: a new test collection for evaluation.
Abstract:
Microblog retrieval in a disaster situation: a new test collection for evaluation
Abstract.
Publications by year
In Press
Roy A, Sundaram S, Nandhakumar M, Thangaian DT, Subramanian B (In Press). An Enduring in vitro Wound Healing Phase Recipient by Bioactive Glass-Graphene Oxide Nanocomposites. Scientific Reports
Bhandari S, Roy A, Ali S, Mallick T, Sundaram S (In Press). Cotton soot derived carbon nanoparticles for NiO supported processing temperature tuned ambient perovskite solar cells. Scientific Reports
Bhandari S, Roy A, Ali S, Mallick T, Sundaram S (In Press). Cotton soot derived carbon nanoparticles for NiO supported processing temperature tuned ambient perovskite solar cells. Scientific Reports
Roy A, Sundaram S, Mallick T (In Press). Cu2ZnSnS4, a Fascinating Counter Electrode for TiO2-Free Dye-Sensitized Solar Cells. Chemistry Select
Roy A, Sundaram S, Mallick T (In Press). Effect of dye sensitization’s temperature on ZnO-based solar cells. Chemical Physics Letters
Roy A, Velusamy S, Sundaram S, Mallick T (In Press). Eggshell Membrane Assisted CdS Nanoparticles for Manganese Removal. Advanced Materials Letters
Roy A, Ghosh A, Benson D, Mallick T, Sundaram S (In Press). Emplacement of screen-printed graphene oxide coating for building thermal comfort discernment. Scientific Reports
Sheikh MS, Roy A, Bhandari S, Mallick T, Sundaram S, Sinha TP (In Press). Highly conductive double perovskite oxides A2LuTaO6 (A= Ba, Sr, Ca) as promising photoanode material for dye sensitized solar cells. Materials Letters
Roy A, Ghosh A, Bhandari S, Mallick T, Sundaram S (In Press). Incorporating Solution-Processed Mesoporous WO3 as an Interfacial Cathode Buffer Layer for Photovoltaic Applications. The Journal of Physical Chemistry Part A: Molecules, Spectroscopy, Kinetics, Environment and General Theory
Roy A, Bhandari S, Sundaram S, Mallick T (In Press). Intriguing CeO2-TiO2 hybrid nanostructured photoanode resulting up to 46% efficiency enhancement for dye-sensitized solar cells. Materials Chemistry and Physics
Roy A, Bhandari S, Ghosh A, Mallick T, Sundaram S (In Press). Performance of WO3 Incorporated Carbon Electrodes for Ambient Mesoscopic Perovskite Solar Cells.
ACS OmegaAbstract:
Performance of WO3 Incorporated Carbon Electrodes for Ambient Mesoscopic Perovskite Solar Cells
The stability of perovskite solar cells (PSC) is often compromised by the organic hole transport materials (HTMs). We report here the effect of WO3 as an inorganic HTM for carbon electrodes for improved stability in PSCs which are made under ambient conditions. Sequential fabrication of the PSC was performed under ambient conditions with mesoporous TiO2/Al2O3/CH3NH3PbI3 layers and, on the top of these layers, the nanoparticles embedded carbon electrode was used. Different concentrations of WO3 nanoparticles as HTM incorporated in carbon counter electrodes were tested, which varied the stability of the cell under ambient conditions. The addition of 7.5% WO3 (by volume) led to a maximum power conversion efficiency of 10.5%, whereas the stability of the cells under ambient condition was ~350 h, maintaining ~80% of the initial efficiency under light illumination. At the same time, the higher WO3 concentration exhibited a high efficiency of 9.5%, which was stable up to ~500 h with a loss of only ~15% of the initial efficiency under normal atmospheric conditions and light illumination. This work demonstrates an effective way to improve the stability of carbon based perovskite solar cells without affecting the efficiency for future applications.
Abstract.
Roy A, Mukhopadhyay S, Parukuttyamma SD, Sundaram S (In Press). Polyaniline Layered Rutile TiO2 Nanorod as an Alternative Photoanode in Dye Sensitized Solar Cell. ACS Omega
Roy A (In Press). Role of vanadium ions substitution on spinel. MnCo2O4 towards enhanced electrocatalytic activity for hydrogen generation. Scientific Reports
Roy A, Ullah H, Ghosh A, Baig H, Sundaram S, Tahir A, Mallick T (In Press). Understanding the Semi-switchable Thermochromic Behavior of Mixed Halide Hybrid Perovskite Nanorods. The Journal of Physical Chemistry C: Energy Conversion and Storage, Optical and Electronic Devices, Interfaces, Nanomaterials, and Hard Matter
2023
Sadhukhan P, Roy A, Bhandari S, Mallick TK, Das S, Sundaram S (2023). Achieving high open circuit voltage for hole transport layer free ambient perovskite solar cells utilizing electric double layer effect.
Solar Energy Materials and Solar Cells,
251Abstract:
Achieving high open circuit voltage for hole transport layer free ambient perovskite solar cells utilizing electric double layer effect
One of the features of perovskite solar cells (PSCs) that make them stand out among all photovoltaics (PVs) is their high open-circuit voltage (VOC). Owing to their simple manufacturing process, low cost of components, and good stability, carbon electrode-based metal-halide PSCs are gaining interest for their better stability and low cost than noble metal electrodes. However, carbon electrode-based hybrid PSCs suffer low open-circuit voltage (VOC). This work demonstrated the fabrication of ambient processed hybrid perovskite solar cells using low-temperature curable carbon-based electrodes without a hole transport layer. The devices exhibit an impressive high open circuit voltage of 1.07 V, even without a dedicated hole transport layer. The photovoltaic performance was further investigated with the same perovskite absorber, synthesized by solution-processed and solid-state synthesis routes. The latter have yielded better short circuit current and power conversion efficiency due to perovskite's lesser built-in trap density. Furthermore, using a combined ionic electronic carrier transport model, an electric double-layer formation was ensured across the perovskite/carbon interface and accumulating halide vacancies at the perovskite/TiO2 interface can effectively reduce carrier recombination and boost the device's VOC. This study envisages the impact of the electric double layer in free carrier transport of an ionic-electronic semiconductor like hybrid perovskites and can pave the way to improve the open-circuit voltage of carbon-based perovskite solar cells.
Abstract.
Roy A, Ding B, Khalid M, Alzahrani M, Ding Y, Tahir AA, Sundaram S, Kinge S, Asiri AM, Slonopas A, et al (2023). Certified high-efficiency "large-area" perovskite solar cells module for Fresnel lens-based concentrated photovoltaic. iScience, 106079-106079.
Valsalakumar S, Roy A, Mallick TK, Hinshelwood J, Sundaram S (2023). Mesoporous TiO2-layer’s rheological impact on the perovskite solar cell performance. Materials Letters, 337
2022
Al-Fartoos MMR, Roy A, Mallick TK, Tahir AA (2022). A Short Review on Thermoelectric Glazing for Sustainable Built Environment.
Energies,
15(24), 9589-9589.
Abstract:
A Short Review on Thermoelectric Glazing for Sustainable Built Environment
Securing net-zero targets by employing sustainable materials for the built environment is highly desirable, and this can be achieved by retrofitting existing non-smart windows with thermoelectric (TE) glazing, providing improved thermal performance along with green electricity production. It is reported that TE glazing could produce ~4000 kWh of power per year in a cold climate with a temperature differential of ~22 °C. This feature of TE materials drives their emplacement as an alternative to existing glazing materials and could lead to the identification of optimum solutions for smart window development. However, few attempts have been made to employ TE materials in glazing. Therefore, in this brief review, we discuss, for the first time, the efforts made to employ TE in glazing, identify their drawbacks, and discuss potential solutions. Furthermore, the working principle, suitable materials, and methods for developing TE glazing are discussed. In addition, this article introduces a new research area and provides researchers with detailed instructions on how to build and optimize this system. The maximum efficiency of a thermoelectric material is determined by its thermoelectric figure of merit, which is a well-defined metric to characterize a device operating between the hot-side and cold-side temperatures. TE material’s figure of merit promises new perspectives on the conceivable future energy-positive built environment. The role of TE in tackling the energy crisis is also discussed, since it provides sustainable energy alternatives
Abstract.
Sen S, Roy A, Sanyal A, Devi PS (2022). A nonenzymatic reduced graphene oxide-based nanosensor for parathion.
Beilstein Journal of Nanotechnology,
13, 730-744.
Abstract:
A nonenzymatic reduced graphene oxide-based nanosensor for parathion
Organophosphate-based pesticides (e.g. parathion (PT)) have toxic effects on human health through their residues. Therefore, cost-effective and rapid detection strategies need to be developed to ensure the consuming food is free of any organophosphate-residue. This work proposed the fabrication of a robust, nonenzymatic electrochemical-sensing electrode modified with electrochemically reduced graphene oxide (ERGO) to detect PT residues in environmental samples (e.g. soil, water) as well as in vegetables and cereals. The ERGO sensor shows a significantly affected electrocatalytic reduction peak at −0.58 V (vs Ag/AgCl) for rapid quantification of PT due to the amplified electroactive surface area of the modified electrode. At optimized experimental conditions, square-wave voltammetric analysis exhibits higher sensitivity (50.5 μA·μM−1·cm−2), excellent selectivity, excellent stability (≈180 days), good reproducibility, and repeatability for interference-free detection of PT residues in actual samples. This electrochemical nanosensor is suitable for point-of-care detection of PT in a wide dynamic range of 3 × 10−11–11 × 10−6 M with a lower detection limit of 10.9 pM. The performance of the nanosensor was validated by adding PT to natural samples and comparing the data via absorption spectroscopy. PT detection results encourage the design of easy-to-use nanosensor-based analytical tools for rapidly monitoring other environmental samples.
Abstract.
Nandhakumar NM, T TDT, Sundaram S, Roy A, S B (2022). An Enduring in vitro Wound Healing Phase Recipient by Bioactive Glass- Graphene Oxide Nanocomposites.
Valsalakumar S, Roy A, Mallick TK, Hinshelwood J, Sundaram S (2022). An Overview of Current Printing Technologies for Large-Scale Perovskite Solar Cell Development.
Energies,
16(1), 190-190.
Abstract:
An Overview of Current Printing Technologies for Large-Scale Perovskite Solar Cell Development
The power conversion efficiencies (PCEs) of Perovskite solar cells (PSCs) have seen significant performance improvements between 2012 and 2022. PSCs have excellent optoelectronic properties and can be built using low-cost materials. In order to compete with first-generation photovoltaic technologies, it will be necessary to scale up production. This review article explores the advancements in several scalable perovskite deposition techniques, including recent developments in the fabrication of high-quality perovskite film, their stabilities and commercialization status. Several scalable deposition techniques are discussed, including user-friendly solution-techniques (spin coating, slot die coating, etc.), vapour-assisted deposition approaches in the laboratory and full-scale commercial applications. The aforementioned deposition techniques have advantages compared to deposition techniques based on cost, effective mask-less patterning and unparalleled-design freedom. Other potential advantages include optimal use of materials, scalability, contactless deposition in high-resolution and a rapid transformation from small laboratory-scale work to large industrial-scale roll-to-roll production. Most recent technological advancements and structural developments relate to long-term thermal stability and moisture resistance. Many of the developments are still in the evolving field of lab-scale devices. The improvement roadmap and commercialization aspects of PSC manufacture involve two significant milestones: bridging the gap between the performance characteristics of small-scale and large-scale devices and the scalable printing techniques for all the layers in the device.
Abstract.
Roy A, Mallick TK, Tahir AA (2022). An optimal climate-adaptable hydrogel-filled smart window for the energy-saving built environment.
Journal of Materials Chemistry C,
10(41), 15474-15482.
Abstract:
An optimal climate-adaptable hydrogel-filled smart window for the energy-saving built environment
It is highly desirable to secure the net-zero targets by employing sustainable building materials that can store and release their energy depending on the weather.
Abstract.
Roy A, Mohamed MJS, Gondal MA, Mallick TK, Tahir AA, Sundaram S (2022). Co-sensitization effect of N719 dye with Cu doped CdS colloidal nanoparticles for dye sensitized solar cells. Inorganic Chemistry Communications, 148, 110298-110298.
Bhandari S, Ghosh A, Roy A, Mallick TK, Sundaram S (2022). Compelling temperature behaviour of carbon-perovskite solar cell for fenestration at various climates. Chemical Engineering Journal Advances, 10
Velusamy S, Roy A, Sundaram S, Mallick TK (2022). Concern for heavy metal ion water pollution. In (Ed) Contaminants of Emerging Concerns and Reigning Removal Technologies, 257-284.
Roy A, Ullah H, Ghosh A, Mallick TK, Tahir AA (2022). Corrigendum to “Smart glazing thermal comfort improvement through near-infrared shielding paraffin incorporated SnO2-Al2O3 composite” [Constr. Build. Mater. 331 (2022) 127319]. Construction and Building Materials, 341
Velusamy S, Roy A, Sundaram S, Mallick TK (2022). Employing CdS nanoparticles as an adsorbent for the removal of different dosages of hexavalent Cr (VI) from aqueous solution.
Materials Letters,
311Abstract:
Employing CdS nanoparticles as an adsorbent for the removal of different dosages of hexavalent Cr (VI) from aqueous solution
The discharge of chromium effluent from various industries becomes a severe threat to the environment, creating a risk to human health and environmental aspects. In this study, Cr (VI) removal from aqueous solution by adsorption was investigated using commercially available CdS at different concentrations to consider an industrial-level large-scale application. Adsorption efficiency depends on a few parameters: pH, adsorbent dosage, initial concentration of Cr (VI) solution, temperature and contact time. For understanding the adsorption process, adsorption kinetics and adsorption Isotherm studies were applied to check the best fit mechanism of the adsorption process. The pseudo-second-order kinetics followed by the Langmuir adsorption isotherm model is the most fitted model for removing chromium using CdS. This study signifies another toxic compound, CdS, that can effectively convert Cr (VI) toxic to Cr (III) non-toxic state.
Abstract.
Alruwaili M, Roy A, Nundy S, Tahir AA (2022). Fabrication of TiVO<sub>4</sub> photoelectrode for photoelectrochemical application.
RSC Advances,
12(53), 34640-34651.
Abstract:
Fabrication of TiVO4 photoelectrode for photoelectrochemical application
TiVO4 photoanode was prepared using the spray pyrolysis technique and further employed for photoelectrochemical water splitting to produce hydrogen.
Abstract.
Sheikh MS, Ghosh A, Roy A, Bhandari S, Sundaram S, Mallick TK, Ghosh H, Sinha TP (2022). High Open-Circuit Voltage in Double Perovskite Oxide A(2)NdSbO(6) (A = Ba, Sr) Photoanode-Based Dye-Sensitized Solar Cells.
JOURNAL OF ELECTRONIC MATERIALS,
51(8), 4281-4287.
Author URL.
Yadav A, Kumar P, Rawat D, Garg S, Mukherjee P, Farooqi F, Roy A, Sundaram S, Sharma RS, Mishra V, et al (2022). Microbial fuel cells for mineralization and decolorization of azo dyes: Recent advances in design and materials.
Sci Total Environ,
826Abstract:
Microbial fuel cells for mineralization and decolorization of azo dyes: Recent advances in design and materials.
Microbial fuel cells (MFCs) exhibit tremendous potential in the sustainable management of dye wastewater via degrading azo dyes while generating electricity. The past decade has witnessed advances in MFC configurations and materials; however, comprehensive analyses of design and material and its association with dye degradation and electricity generation are required for their industrial application. MFC models with high efficiency of dye decolorization (96-100%) and a wide variation in power generation (29.4-940 mW/m2) have been reported. However, only 28 out of 104 studies analyzed dye mineralization - a prerequisite to obviate dye toxicity. Consequently, the current review aims to provide an in-depth analysis of MFCs potential in dye degradation and mineralization and evaluates materials and designs as crucial factors. Also, structural and operation parameters critical to large-scale applicability and complete mineralization of azo dye were evaluated. Choice of materials, i.e. bacteria, anode, cathode, cathode catalyst, membrane, and substrate and their effects on power density and dye decolorization efficiency presented in review will help in economic feasibility and MFCs scalability to develop a self-sustainable solution for treating azo dye wastewater.
Abstract.
Author URL.
Bhandari S, Roy A, Mallick TK, Sundaram S (2022). Morphology modulated brookite TiO2 and BaSnO3 as alternative electron transport materials for enhanced performance of carbon perovskite solar cells. Chemical Engineering Journal, 446, 137378-137378.
Khalid M, Roy A, Bhandari S, Selvaraj P, Sundaram S, Mallick TK (2022). Opportunities of copper addition in CH3NH3PbI3 perovskite and their photovoltaic performance evaluation. Journal of Alloys and Compounds, 895, 162626-162626.
Rokade AV, Jadhav YA, Jathar S, Rahane S, Barma S, Rahane GK, Thawarkar S, Vairale P, Punde A, Shah S, et al (2022). Realization of Electrochemically Grown α-Fe<inf>2</inf>O<inf>3</inf> Thin Films for Photoelectrochemical Water Splitting Application.
Engineered Science,
17, 242-255.
Abstract:
Realization of Electrochemically Grown α-Fe2O3 Thin Films for Photoelectrochemical Water Splitting Application
Hematite ferric oxide (α-Fe2O3) based photoanode has emerged as a potential candidate for water splitting application due to its high absorption coefficient in the visible region and favorable band alignment. In the present work, α-Fe2O3 thin film photoanodes were fabricated using a cost-effective and straightforward electrodeposition technique. The crystal structure, phase purity, elemental composition, and formation of α-Fe2O3 were confirmed by X-ray diffraction (XRD), photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, energy-dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). The bandgap calculated from the absorption spectrum from UV-visible analysis of α-Fe2O3 exhibited a significant absorption in the visible region. The α-Fe2O3 photoanodes were further characterized for their photoelectrochemical (PEC) properties along with electrochemical impedance spectroscopy (EIS) analysis. Furthermore, XRD, SEM, and Fourier transform infrared (FTIR) spectroscopy investigations were performed after photoelectrochemical measurement to ensure the stability of photoanodes. Also, the prepared photoanode was highly stable against a large range of pH conditions, and no photobleaching was observed for up to 30 min. Furthermore, a significant enhancement in the photocurrent conversion efficiency with an optimum film thickness was observed upon light illumination. A maximum photon conversion efficiency of 1.44 % was obtained with a photocurrent density of 6.25 mA/cm2 for 1 V vs. saturated calomel electrode (SCE) under the simulated solar light.
Abstract.
Roy A, Ghosh A, Mallick TK, Tahir AA (2022). Smart glazing thermal comfort improvement through near-infrared shielding paraffin incorporated SnO<inf>2</inf>-Al<inf>2</inf>O<inf>3</inf> composite.
Construction and Building Materials,
331Abstract:
Smart glazing thermal comfort improvement through near-infrared shielding paraffin incorporated SnO2-Al2O3 composite
Building's energy conservation signifies a lowering in building energy consumption without sacrificing thermal comfort. Window glazing is the most suitable approach to the built environment that can be controlled through its sustainable development for global energy consumption. In this work, for the first time, paraffin incorporated SnO2-Al2O3 composite coating is developed on a 5 cm × 5 cm glass using a screen-printing method, which signifies an intelligent cooling behaviour for a comfortable indoor environment irrespective of their emplacement. The composite energy-saving properties exhibit less transmission of infra-red light while keeping high visible light transmittance behaviour resulting superior heat-shielding performance. The composite coated glass's average indoor temperature profile remains at ∼30 °C when the outside temperature reaches a maximum of 45 °C during outdoor testing. While the same composite film is set inside, the indoor average temperature maintains ∼30 °C, whereas outside temperature reaches a maximum of 80 °C. The distinct temperature profile for composite coated glass indicates high transparency of 80% throughout the experiment. Interestingly paraffin has been incorporated into the composite, offering no leakage, translucent characteristics, and limited water ingress. In comparison, non-coated glass is failed to provide them with a comfortable, stable indoor temperature. We believe this study envisages the recent technological innovations combined with phase change material and transparent infrared absorber together as a composite for window glass for warmer climates, which further leads to significant energy savings compared with plain glass.
Abstract.
Roy AS, Pack K, Wittler N, Machnes S (2022). Software tool-set for automated quantum system identification and device. bring up.
Roy A, Ullah H, Alzahrani M, Ghosh A, Mallick TK, Tahir AA (2022). Synergistic effect of paraffin incorporated In2O3:ZnO multi-fold composite smart glazing for the self-cleaning and energy-saving built environment.
ACS Sustainable Chemistry and Engineering,
10, 6609-6621.
Abstract:
Synergistic effect of paraffin incorporated In2O3:ZnO multi-fold composite smart glazing for the self-cleaning and energy-saving built environment
The thermal performance of window glazing requires improvement for a sustainable built environment at an acceptable cost. The current work demonstrates a multifold smart composite consisting of an optimized In2O3/ZnO–polymethyl methacrylate–paraffin composite to reduce heat exchange through the combined self-cleaning and energy-saving envelope of the smart built environment. This work has attempted to develop a smart composite coating that combines photosensitive metal oxide and phase change materials and investigate their thermal comfort performance as a glazed window. It is observed that the In2O3/ZnO (5 wt %) multifold composite film experienced better transmittance and thermal performance compared to its other wt % composite samples. Moreover, the multifold composite-coated glass integrated into a prototype glazed window was further investigated for its thermal performance, where a steady average indoor temperature of ∼30 °C was achieved when the outside temperature reached ∼55 °C, while maintaining good visibility. Interestingly, the transparency reached ∼86% at 60 °C and exhibited a hydrophobic water contact angle (WCA) of ∼138°. In contrast, a similar film exhibits ∼64% transparency at 22 °C, where the WCA becomes moderately hydrophilic (∼68°). Temperature dependency on transparency and wettability properties was examined for up to 60 cycles, resulting in excellent indoor thermal comfort. In addition, a thermal simulation study was executed for the smart multifold glazing composite. Moreover, this study offers dynamic glazing development options for energy saving in the smart built environment.
Abstract.
2021
Ghosh P, Roy A, Mukhopadhyay S, Narjinary M, Sundaram S, Sen S, Devi PS (2021). A New Functional Composite for Photovoltaic and Sensor Applications. Advanced Electronic Materials, 7(3), 2000785-2000785.
Velusamy S, Roy A, Sundaram S, Mallick TK (2021). A Review on Heavy Metal Ions and Containing Dyes Removal Through Graphene Oxide-Based Adsorption Strategies for Textile Wastewater Treatment. The Chemical Record
Roy A, Ghosh S, Ghosh K, Ghosh S (2021). An Unsupervised Normalization Algorithm for Noisy Text: a Case Study for Information Retrieval and Stance Detection.
Journal of Data and Information Quality,
13(3).
Abstract:
An Unsupervised Normalization Algorithm for Noisy Text: a Case Study for Information Retrieval and Stance Detection
A large fraction of textual data available today contains various types of "noise,"such as OCR noise in digitized documents, noise due to informal writing style of users on microblogging sites, and so on. To enable tasks such as search/retrieval and classification over all the available data, we need robust algorithms for text normalization, i.e. for cleaning different kinds of noise in the text. There have been several efforts towards cleaning or normalizing noisy text; however, many of the existing text normalization methods are supervised and require language-dependent resources or large amounts of training data that is difficult to obtain. We propose an unsupervised algorithm for text normalization that does not need any training data/human intervention. The proposed algorithm is applicable to text over different languages and can handle both machine-generated and human-generated noise. Experiments over several standard datasets show that text normalization through the proposed algorithm enables better retrieval and stance detection, as compared to that using several baseline text normalization methods.
Abstract.
Velusamy S, Roy A, Sundaram S, Mallick TK (2021). Cover Picture: a Review on Heavy Metal Ions and Containing Dyes Removal Through Graphene Oxide‐Based Adsorption Strategies for Textile Wastewater Treatment (Chem. Rec. 7/2021). The Chemical Record, 21(7), 1569-1569.
Roy A, Sundaram S, Mallick TK (2021). Cu<inf>2</inf>ZnSnS<inf>4</inf>, a Fascinating Counter Electrode for TiO<inf>2</inf>-Free Dye-Sensitized Solar Cells.
ChemistrySelect,
6(7), 1541-1547.
Abstract:
Cu2ZnSnS4, a Fascinating Counter Electrode for TiO2-Free Dye-Sensitized Solar Cells
Since innovation, different dye-sensitized solar cells (DSSCs) have endeavored with additional components to escalate the efficiency, cost-effectiveness and long-term stability. Various approaches have been executed to reduce the amount of costly platinum (Pt) used in DSSCs and/or to explore cheaper alternatives to Pt. In this work, cheaper elements based quaternary chalcogenide alloy; Cu2ZnSnS4 (CZTS) has been projected as a prominent counter electrode (CE) candidate to Pt in DSSCs. The CZTS thin film has been developed by an in-situ synthesis employing a hydrothermal technique and further evaluating various physicochemical characterization. Our results manifest that using the CZTS CE, a power conversion efficiency (PCE) of 4.3 % was exhibited for TiO2 based photoanode. The highest PCE of 6.5 % was achieved for BaSnO3 based photoanode, a promising alternative oxide to TiO2 photoanode. This work further signifies a unique combination of newly developed BaSnO3(BSO)-CZTS DSSCs, could be a promising competitor to TiO2-Pt DSSCs.
Abstract.
Alzahrani M, Roy A, Shanks K, Sundaram S, Mallick TK (2021). Graphene as a pre-illumination cooling approach for a concentrator photovoltaic (CPV) system. Solar Energy Materials and Solar Cells, 222, 110922-110922.
Chanchangi YN, Roy A, Ghosh A, Sundaram S, Mallick TK (2021). In-situ assessment of photovoltaic soiling mitigation techniques in northern Nigeria. Energy Conversion and Management, 244, 114442-114442.
Wittler N, Roy F, Pack K, Werninghaus M, Roy AS, Egger DJ, Filipp S, Wilhelm FK, Machnes S (2021). Integrated Tool Set for Control, Calibration, and Characterization of Quantum Devices Applied to Superconducting Qubits.
Physical Review Applied,
15(3).
Abstract:
Integrated Tool Set for Control, Calibration, and Characterization of Quantum Devices Applied to Superconducting Qubits
Efforts to scale-up quantum computation have reached a point where the principal limiting factor is not the number of qubits, but the entangling gate infidelity. However, the highly detailed system characterization required to understand the underlying error sources is an arduous process and impractical with increasing chip size. Open-loop optimal control techniques allow for the improvement of gates but are limited by the models they are based on. To rectify the situation, we provide an integrated open-source tool set for control, calibration, and characterization (C3), capable of open-loop pulse optimization, model-free calibration, model fitting, and refinement. We present a methodology to combine these tools to find a quantitatively accurate system model, high-fidelity gates, and an approximate error budget, all based on a high-performance, feature-rich simulator. We illustrate our methods using simulated fixed-frequency superconducting qubits for which we learn model parameters with less than 1% error and derive a coherence-limited cross-resonance gate that achieves 99.6% fidelity without the need for calibration.
Abstract.
Khalid M, Roy A, Bhandari S, Sundaram S, Mallick TK (2021). Integrating Concentrated Optics for Ambient Perovskite Solar Cells.
ENERGIES,
14(9).
Author URL.
Alzahrani MM, Roy A, Sundaram S, Mallick TK (2021). Investigation of Thermal Stress Arising in a Graphene Neutral Density Filter for Concentrated Photovoltaic System.
ENERGIES,
14(12).
Author URL.
Sheikh MS, Roy A, Dutta A, Sundaram S, Mallick TK, Sinha TP (2021). Nanostructured perovskite oxides for dye-sensitized solar cells.
JOURNAL OF PHYSICS D-APPLIED PHYSICS,
54(49).
Author URL.
Roy A, Ullah H, Ghosh A, Mallick T, Tahir AA (2021). Smart Glazing Thermal Comfort Improvement Through Near-Infrared Shielding Paraffin Incorporated Sno2-Al2o3 Composite.
Das PP, Roy A, Devi PS, Lee Y (2021). Solution processed Al-doped ZnO and its performance in dye sensitized solar cells.
Current Applied Physics,
30, 69-76.
Abstract:
Solution processed Al-doped ZnO and its performance in dye sensitized solar cells
Al-doped ZnO rods of nanometer to sub-micrometer size range have been successfully synthesized by a simple yet cost-effective solution processed sonochemical technique. Systematic XRD analysis established the solid solubility limit for Al in the ZnO lattice to be ca. 3 mol% at an elevated annealing temperature of 800 °C. The secondary ZnAl2O4 phase appears with increasing dopant concentrations and at lower annealing temperatures. Significant variations in the optoelectronic properties are induced by modifications in the surface defects of ZnO rods as a result of Al doping. As a consequence, an improved fill factor (FF) of 74.78 and 75.76% with a conversion efficiency (η) of 1.59 and 1.79% have been achieved for the fabricated DSSC devices made of the 800 °C annealed ZnO rods doped by 1 and 3 mol% Al, respectively.
Abstract.
Sinhababu M, Roy A, Kumar N, Dutta M, Sundaram S, Karazhanov S, Udayabhanu G (2021). Surface Treatment of Industrial-Grade Magnetite Particles for Enhanced Thermal Stability and Mitigating Paint Contaminants.
Nanomaterials,
11(9), 2299-2299.
Abstract:
Surface Treatment of Industrial-Grade Magnetite Particles for Enhanced Thermal Stability and Mitigating Paint Contaminants
Pigments can retain their color for many centuries and can withstand the effects of light and weather. The paint industry suffers from issues like aggressive moisture, corrosion, and further environmental contamination of the pigment materials. Low-cost, long-lasting, and large-scale pigments are highly desirable to protect against the challenges of contamination that exist in the paint industry. This exploratory study reinforces the color and thermal stability of industrial-grade (IG) magnetite (Fe3O4). IG Fe3O4 pigments were further considered for surface treatment with sodium hexametaphosphate (SHMP). This metaphosphate hexamer sequestrant provides good dispersion ability and a high surface energy giving thermal and dust protection to the pigment. Various physicochemical characterizations were employed to understand the effectiveness of this treatment across various temperatures (180–300 °C). The X-ray diffraction, Raman, and X-ray photoelectron spectroscopy techniques signify that the SHMP-treated Fe3O4 acquired magnetite phase stability up to 300 °C. In addition, the delta-E color difference method was also adopted to measure the effective pigment properties, where the delta-E value significantly decreased from 8.77 to 0.84 once treated with SHMP at 300 °C. The distinct color retention at 300 °C and the improved dispersion properties of surface-treated Fe3O4 positions this pigment as a robust candidate for high-temperature paint and coating applications. This study further encompasses an effort to design low-cost, large-scale, and thermally stable pigments that can protect against UV-rays, dust, corrosion, and other color contaminants that are endured by building paints.
Abstract.
Sadhukhan P, Roy A, Sengupta P, Das S, Mallick TK, Nazeeruddin MK, Sundaram S (2021). The emergence of concentrator photovoltaics for perovskite solar cells.
APPLIED PHYSICS REVIEWS,
8(4).
Author URL.
Wang S, Roy A, Komvopoulos K (2021). Thermal stability and diffusion characteristics of ultrathin amorphous carbon films grown on crystalline and nitrogenated silicon substrates by filtered cathodic vacuum arc deposition.
Scientific Reports,
11(1).
Abstract:
Thermal stability and diffusion characteristics of ultrathin amorphous carbon films grown on crystalline and nitrogenated silicon substrates by filtered cathodic vacuum arc deposition
Amorphous carbon (a-C) films are widely used as protective overcoats in many technology sectors, principally due to their excellent thermophysical properties and chemical inertness. The growth and thermal stability of sub-5-nm-thick a-C films synthesized by filtered cathodic vacuum arc on pure (crystalline) and nitrogenated (amorphous) silicon substrate surfaces were investigated in this study. Samples of a-C/Si and a-C/SiNx/Si stacks were thermally annealed for various durations and subsequently characterized by high-resolution transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS). The TEM images confirmed the continuity and uniformity of the a-C films and the 5-nm-thick SiNx underlayer formed by silicon nitrogenation using radio-frequency sputtering. The EELS analysis of cross-sectional samples revealed the thermal stability of the a-C films and the efficacy of the SiNx underlayer to prevent carbon migration into the silicon substrate, even after prolonged heating. The obtained results provide insight into the important attributes of an underlayer in heated multilayered media for preventing elemental intermixing with the substrate, while preserving the structural stability of the a-C film at the stack surface. An important contribution of this investigation is the establishment of an experimental framework for accurately assessing the thermal stability and elemental diffusion in layered microstructures exposed to elevated temperatures.
Abstract.
2020
Roy A, Sundaram S, Mallick T, ghosh P, Sujatha Devi P (2020). Efficient carbon counter electrodes for BaSnO3-based dye-sensitized solar cells. Materials Today: Proceedings
Bhandari S, Roy A, Mallick T, Sundaram S (2020). Impact of different light induced effect on organic hole-transporting layer in perovskite solar cells. Materials Letters
Wittler N, Roy F, Pack K, Werninghaus M, Roy AS, Egger DJ, Filipp S, Wilhelm FK, Machnes S (2020). Integrated tool-set for Control, Calibration and Characterization of. quantum devices applied to superconducting qubits.
Bhandari S, Roy A, Ghosh A, Mallick T, Sundaram S (2020). Perceiving the Temperature Coefficients of Carbon-based Perovskite Solar Cells. Sustainable Energy and Fuels
Roy A, Ghosh A, Bhandari S, Sundaram S, Mallick T (2020). Perovskite Solar Cells for BIPV Application: a Review. Buildings, 10
Roy A, Ghosh A, Bhandari S, Sundaram S, Mallick TK (2020). Realization of Poly(methyl methacrylate)-Encapsulated Solution-Processed Carbon-Based Solar Cells: an Emerging Candidate for Buildings’ Comfort. Industrial & Engineering Chemistry Research, 59(23), 11063-11071.
Roy A, Velusamy S, Mallick TK, Sundaram S (2020). Synergistic effect of nanoflower-like CdS for removal of highly toxic aqueous Cr(VI). Materials Letters, 270, 127734-127734.
2019
Roy A, Ghosh A, Bhandari S, Selvaraj P, Sundaram S, Mallick TK (2019). Color Comfort Evaluation of Dye-Sensitized Solar Cell (DSSC) Based Building-Integrated Photovoltaic (BIPV) Glazing after 2 Years of Ambient Exposure. The Journal of Physical Chemistry C, 123(39), 23834-23837.
Selvaraj P, Roy A, Ullah H, Sujatha Devi P, Tahir AA, Mallick TK, Sundaram S (2019). Soft-template synthesis of high surface area mesoporous titanium dioxide for dye-sensitized solar cells.
International Journal of Energy Research,
43(1), 523-534.
Abstract:
Soft-template synthesis of high surface area mesoporous titanium dioxide for dye-sensitized solar cells
In the present work, 10 to 14 nm titania nanoparticles with high-packing density are synthesized by the soft-template method using a range of cationic surfactants including cetyl trimethylammonium bromide (CTAB), Sodium dodecyl sulfate (SDS), and dodecyl trimethylammonium bromide (DTAB). The synthesized nanoparticles are used as a photoanode material in dye solar cells. Density functional theory (DFT) simulations reproduce our experimental results of charge transfer and strong interaction between the TiO2 and N719. N719-TiO2 complex establishes strong electrostatic bonding through H of the dye with the O of TiO2 surface. Solar cell efficiency of 6.08% with 12.63 mA/cm2, 793 mV, and 48.5% for short circuit current density, open circuit voltage, and fill factor, respectively, are obtained under 1 sun illumination for the dye-sensitized solar cell (DSSC) using a film of mesoporous TiO2 synthesized from the SDS surfactant. On the other hand, the 21 nm commercial TiO2 powder (P25) device results in 4.60% efficiency under similar conditions. Electrochemical impedance spectroscopic studies show that the SDS device has lesser charge transport resistance than the other devices because of its higher surface area, packing density, and dye loading capacity. Our results show that employing high packing density-based TiO2 nanoparticles represents a commercially viable approach for highly beneficial photoanode development for future DSSC applications.
Abstract.
Roy A, Das PP, Selvaraj P, Devi PS, Sundaram S (2019). Template free synthesis of CdSnO<inf>3</inf> micro-cuboids for dye sensitized solar cells.
Journal of Photochemistry and Photobiology A: Chemistry,
380Abstract:
Template free synthesis of CdSnO3 micro-cuboids for dye sensitized solar cells
Mesoporous transparent conducting oxide, CdSnO3 has been synthesized using ultrasonication assisted co-precipitation method. Rather employing any template or structure directing agent, the co-precipitation effect of sodium hydroxide and citric acid were able to form cuboid shaped CdSnO3 during the sonochemical treatment as investigated by a systematic X-ray diffraction and field emission scanning electron microscopy studies. An optimum 3:1 molar concentration of NaOH and citric acid leads to form cuboidal structure of CdSnO3 on calcined at 700 °C. Further calcination at 800 °C converted cuboids to nanoparticles. Comparative studies have been carried out between the cuboid and particle morphology to understand the physico-chemical properties related to the morphology using various characterization techniques. Further, the CTO cuboids and the decomposed nanoparticles have been tested as photoanode for dye sensitized solar cell applications. The cuboid based photoanode exhibited an enhanced efficiency of 3.23% with a VOC of 0.72 V than its decomposed nanoparticle which exhibited a lower efficiency of 2.67%. The electrochemical impedance and incident photon to electron conversion efficiency results also support enhanced performance of cuboid based device than particle. The overall results show the advantage of cuboidal CdSnO3 in rapid electron injection and higher light reflection leading to improved current density of the DSSC device than the decomposed nanoparticle form. The results establish the application of less explored CdSnO3 as a photoanode in DSSCs application.
Abstract.
2018
Roy A, Devi PS, Karazhanov S, Mamedov D, Mallick TK, Sundaram S (2018). A review on applications of Cu<inf>2</inf>ZnSnS<inf>4</inf> as alternative counter electrodes in dye-sensitized solar cells.
AIP Advances,
8(7).
Abstract:
A review on applications of Cu2ZnSnS4 as alternative counter electrodes in dye-sensitized solar cells
A contribution of counter electrode (CE) emphasis a great impact towards enhancement of a dye-sensitized solar cell's (DSSC) performance and Pt based CE sets a significant benchmark in this field. Owing to cost effective noble metal, less abundance and industrial large scale application purpose, an effective replacement for Pt is highly demanded. There are several approaches to improve the performance of a CE for enhancing the power conversion efficiency with a less costly and facile device. To address this issue, reasonable efforts execute to find out suitable replacement of Pt is becoming a challenge by keeping the same electrochemical properties of Pt in a cheaper and eco-friendlier manner. With this, cheaper element based quaternary chalcogenide, Cu2ZnSnS4 (CZTS) becomes a prominent alternative to Pt and used as a successful CE in DSSC also. This review presents brief discussion about the basic properties of CZTS including its synthesis strategy, physicochemical properties and morphology execution and ultimate application as an alternative Pt free CE for a low cost based enhanced DSSC device. It is therefore, imperative for engineering of CZTS material and optimization of the fabrication method for the improvement of DSSC performance.
Abstract.
Roy A, Sharma A, Gupta A, Meena V, Harsha AP (2018). Enhanced tribological properties of aluminium using laser-assisted tungsten coating.
World Review of Science, Technology and Sustainable Development,
14(2-3), 102-118.
Abstract:
Enhanced tribological properties of aluminium using laser-assisted tungsten coating
Aluminium (Al) suffers from poor wear and scratch resistance and also low surface hardness. To overcome this, the authors fabricated a ~200 μm coating of fine tungsten (W) powder on Al using laser surface alloying (LSA) with laser power and scanning speed varying from 400–800 W and 800–1,200 mm/min respectively. Material characterisation in the form of SEM and XRD, undertaken on the LSA samples, revealed novel microstructures including formation of intermetallic phases Al4W, Al12W that exhibit substantially higher hardness. Scratch hardness measurements further consolidated that surface hardness of coated samples was more than three times as compared to bulk aluminium. Scratch testing at normal loads of 50–150 N, scratch speed of 30 mm/min, demonstrated a stable friction coefficient of 0.6 and higher coating adhesive strength. When applied to automobile components and aerospace products, the micro-coated LSA samples can provide far better alternatives to the current industrial grade of aluminium from the tribology point of view.
Abstract.
Harsha AP, Roy A, Sharma A, Gupta A, Meena V (2018). Enhanced tribological properties of aluminium using laser-assisted tungsten coating. World Review of Science Technology and Sustainable Development, 14(2/3).
Das PP, Roy A, Agarkar S, Devi PS (2018). Hydrothermally synthesized fluorescent Zn2SnO4 nanoparticles for dye sensitized solar cells. Dyes and Pigments, 154, 303-313.
Sundaram S, Roy A, Selvaraj P, Parukuttyamma SD (2018). Morphology tuned BaSnO 3 active layer for ambient perovskite solar cells. Materials Letters
Das PP, Pramanik S, Chatterjee S, Roy A, Saha A, Devi PS, Kumar GS (2018). Multiband Fluorescent Graphitic Carbon Nanoparticles from Queen of Oils. ACS Sustainable Chemistry & Engineering, 6(8), 10127-10139.
Bhattacharya M, Sivasubramani S, Roy A (2018). Multiobjective placement and sizing of distributed generations in distribution system using global criterion method.
International Transactions on Electrical Energy Systems,
28(1).
Abstract:
Multiobjective placement and sizing of distributed generations in distribution system using global criterion method
This paper presents a multiobjective method for obtaining optimal size and site of distributed generation (DG), to reduce loss, and DG investment cost while improving the voltage profile in primary distribution networks. To solve the multiobjective problem, a classical technique known as global criterion method is implemented to form a novel objective function equation, which is custom-built for a distribution system. The application of the global criterion method is explained using a DG that is capable of injecting real power, ie, unity power factor DG, and then extended to DGs capable of injecting reactive power. The method is validated for 2 distribution systems. Results show that the proposed method satisfies the individual objectives simultaneously. The proposed method is also compared with existing methods to exhibit its effectiveness.
Abstract.
Roy A, Das PP, Selvaraj P, Sundaram S, Sujatha Devi P (2018). Perforated BaSnO3 Nanorods Exhibiting Enhanced Efficiency in Dye Sensitized Solar Cells. ACS Sustainable Chemistry and Engineering, 6, 3299-3310.
2017
Basu M, Roy A, Ghosh K, Bandyopadhyay S, Ghosh S (2017). A novel word embedding based stemming approach for microblog retrieval during disasters.
Abstract:
A novel word embedding based stemming approach for microblog retrieval during disasters
Abstract.
Adedokun O, Roy A, Awodugba AO, Devi PS (2017). Fluorescent carbon nanoparticles from Citrus sinensis as efficient sorbents for pollutant dyes.
LUMINESCENCE,
32(1), 62-70.
Author URL.
Nag P, Das PP, Roy A, Devi PS (2017). Iron antimonate quantum dots exhibiting tunable visible light emission. New Journal of Chemistry, 41(4), 1436-1446.
Basu M, Roy A, Ghosh K, Bandyopadhyay S, Ghosh S (2017). Microblog retrieval in a disaster situation: a new test collection for evaluation.
Abstract:
Microblog retrieval in a disaster situation: a new test collection for evaluation
Abstract.
Roy A, Das PP, Tathavadekar M, Das S, Devi PS (2017). Performance of colloidal CdS sensitized solar cells with ZnO nanorods/nanoparticles.
BEILSTEIN JOURNAL OF NANOTECHNOLOGY,
8, 210-221.
Author URL.
Das PP, Roy A, Tathavadekar M, Devi PS (2017). Photovoltaic and photocatalytic performance of electrospun Zn2SnO4 hollow fibers. Applied Catalysis B Environmental, 203, 692-703.
Dey R, Roy A, Chakraborty T, Ghosh S (2017). Sleeping beauties in Computer Science: characterization and early identification.
Scientometrics,
113(3), 1645-1663.
Abstract:
Sleeping beauties in Computer Science: characterization and early identification
While a large majority of scientific publications get most of their citations within the initial few years after publication, there is an interesting number of papers—termed as sleeping beauties—which do not get much cited for several years after being published, but then suddenly start getting cited heavily. In this work, we focus on sleeping beauties (SBs) in the domain of Computer Science. We identify more than 5,000 sleeping beauties in Computer Science, and characterise them based on their sub-field and their citation profile after awakening. We also reveal some interesting factors which led to their awakening long after publication. Furthermore, we also propose a methodology for early identification of sleeping beauties, and develop a machine learning-based classification approach that attempts to classify publications based on whether they are likely to be SBs. The classifier achieves a precision of 0.73 and a recall of 0.45 in identifying SBs immediately after their year of publications, and the performance significantly improves with time. To our knowledge, this is the first study on sleeping beauties in Computer Science.
Abstract.
2016
Das PP, Roy A, Das S, Devi PS (2016). Enhanced stability of Zn2SnO4 with N719, N3 and eosin Y dye molecules for DSSC application.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS,
18(3), 1429-1438.
Author URL.
Vora HD, Rajamure RS, Roy A, Srinivasan SG, Sundararajan G, Banerjee R, Dahotre NB (2016). Laser Assisted Additively Manufactured Transition Metal Coating on Aluminum.
JOM,
68(7), 1819-1829.
Abstract:
Laser Assisted Additively Manufactured Transition Metal Coating on Aluminum
Various physical and chemical properties of surface and subsurface regions of Al can be improved by the formation of transition metal intermetallic phases (AlxTMy) via coating of the transition metal (TM). The lower equilibrium solid solubility of TM in Al (
Abstract.
Roy A, Chatterjee S, Pramanik S, Devi PS, Kumar GS (2016). Selective detection of Escherichia coli DNA using fluorescent carbon spindles.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS,
18(17), 12270-12277.
Author URL.
Das PP, Roy A, Devi PS (2016). Zn2SnO4 as an Alternative Photoanode for Dye Sensitized Solar Cells: Current Status and Future Scope. Transactions of the Indian Ceramic Society, 75(3), 147-154.
2015
Mahto TK, Roy A, Sahoo B, Sahu SK (2015). Citric Acid Fuctionalized Magnetic Ferrite Nanoparticles for Photocatalytic Degradation of Azo Dye.
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY,
15(1), 273-280.
Author URL.
Das S, Nayak GC, Sahu SK, Routray PC, Roy AK, Baskey H (2015). Microwave absorption properties of double-layer composites using CoZn/NiZn/MnZn-ferrite and titanium dioxide.
Journal of Magnetism and Magnetic Materials,
377, 111-116.
Abstract:
Microwave absorption properties of double-layer composites using CoZn/NiZn/MnZn-ferrite and titanium dioxide
Zinc substituted ferrite powders Me0.5Zn0.5Fe2O4 (Me=Co, Mn and Ni) were prepared by the sol-gel auto-combustion method. The present study highlights development of Single layer and double layer composite microwave absorbing materials using Ferrites, Titanium dioxide and Epoxy matrix. Moreover microwave absorption property, i.e. reflection loss evaluated at X-band frequency. XRD analysis of the filler particles were carried out to evaluate crystal structure, average crystallite diameter. Morphology of the filler particles were studied with FESEM. Hysteresis behavior of the ferrites samples were studied with Vibrating Sample Magnetometer. The most important parameter governing the absorption properties of microwave absorbers i.e. permittivity and permeability studied in a vector network analyzer. Measured reflection loss value of single-layer NiZn-ferrite based microwave absorber reaches -11.2 dB at 12.05 GHz. Whereas, reflection loss value of double-layer CoZn-ferrite/ TiO2 based microwave absorber reaches -24.3 dB at 12.02 GHz. The result shows that microwave absorption property and bandwidth of absorption of double-layer microwave absorber was found to improve comparison to single layer.
Abstract.
Das S, Nayak GC, Sahu SK, Routray PC, Roy AK, Baskey H (2015). Titania-Coated Magnetite and Ni-Ferrite Nanocomposite-Based RADAR Absorbing Materials for Camouflaging Application.
Polymer - Plastics Technology and Engineering,
54(14), 1483-1493.
Abstract:
Titania-Coated Magnetite and Ni-Ferrite Nanocomposite-Based RADAR Absorbing Materials for Camouflaging Application
A novel core–shell-structured nanocomposite material based on titanium dioxide-coated magnetite and Ni-ferrite has been prepared for RADAR absorbing application in a X-band region. The coating of magnetic particles with TiO2 was carried out by in situ hydrolysis of titanium tetrabutoxide, and the composite absorber sheets were prepared with epoxy resin. The morphological characterization of the magnetic particles was studied with field emission scanning electron microscope, transmission electron microscope, X-ray diffraction, and vibrating sample magnetometer analysis techniques. The measurement results confirmed the coating of magnetic particles with TiO2 and reduction of the magnetization of magnetite and Ni-ferrite nanoparticles compared with the uncoated ferrite nanoparticles. Distribution of particle inside the matrix was studied with scanning electron microscope. Microwave absorption study in X-band (8–12 GHz) region was carried out with vector network analyzer. Results showed reflection loss values of −26.5 db at 9.08 GHz for the magnetite coated with titanium dioxide/conducting carbon black containing sample which increased to −45.7 db at 9.13 GHz for the Ni-ferrite coated with TiO2/conducting carbon black formulation. It was observed that coating of magnetic particles resulted in the improvement in the microwave absorption.
Abstract.
2014
Das S, Nayak GC, Sahu SK, Routray PC, Roy AK, Baskey H (2014). Microwave Absorption Properties of Double-Layer RADAR Absorbing Materials Based on Doped Barium Hexaferrite/TiO<inf>2</inf>/Conducting Carbon Black.
Journal of Engineering (United Kingdom),
2014Abstract:
Microwave Absorption Properties of Double-Layer RADAR Absorbing Materials Based on Doped Barium Hexaferrite/TiO2/Conducting Carbon Black
In this report, we demonstrate microwave absorption properties of barium hexaferrite, doped barium hexaferrite, titanium dioxide and conducting carbon black based RADAR absorbing material for stealth application. Double-layer absorbers are prepared with a top layer consisting of 30% hexaferrite and 10% titanium dioxide while the bottom layer composed of 30% hexaferrite and 10% conducting carbon black, embedded in chloroprene matrix. The top and bottom layers are prepared as impedance matching layer and conducting layer, respectively, with a total thickness of 2 mm. Microwave absorption properties of all the composites were analyzed in X-band region. Maximum reflection loss of -32 dB at 10.64 GHz was observed for barium hexaferrite based double-layer absorber whereas for doped barium hexaferrite based absorber the reflection loss was found to be -29.56 dB at 11.7 GHz. A consistence reflection loss value (>-24 dB) was observed for doped barium hexaferrite based RADAR absorbing materials within the entire bandwidth.
Abstract.