Journal Articles
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Item Improving the Performance of Carbon-Based Perovskite Solar Modules (70 cm2) by Incorporating Cesium Halide in Mesoporous TiO2(American Chemical Society, 2021) Keremane, K.S.; Prathapani, S.; Haur, L.J.; Bruno, A.; Priyadarshi, A.; Vasudeva Adhikari, A.V.; Mhaisalkar, S.G.We present the fabrication of highly efficient large-area carbon-based perovskite solar cells (C-PSCs) using CsX (X = Cl, Br, and I)-modified mesoporous (mp) TiO2 beads of 40 nm size as an electron transport material. Here, triple-layered scaffolds made of cesium halide-modified TiO2 exhibit efficient charge extraction as confirmed by enhanced photoluminescence quenching and inhibit the UV-activated degradation processes of perovskite, leading to an enhanced operational stability. Among the three cesium halide modifications, devices containing CsBr-modified TiO2 showed the highest short-circuit current density, yielding a photoconversion efficiency (PCE) of 12.59% of the device, with 0.7 cm2 active area and 11.55% for a large-area module (70 cm2). These devices are stable in an ambient atmosphere (25 °C, 65-70% RH) over 2700 h as well as at a high temperature (85 °C) over 750 h with virtually no hysteresis. © 2021 American Chemical Society. All rights reserved.Item Unveiling the Potential of Cs3Sb2ClxI9-x-Based Solar Cells for Efficient Indoor Light Harvesting: Numerical Simulation(John Wiley and Sons Inc, 2024) Manjhi, S.; Siddharth, G.; Pandey, S.K.; Sengar, B.S.; Garg, V.Lead-free Perovskite-inspired materials (PIM) have become the most promising candidate for indoor photovoltaics (IPV) because of their low toxicity and high performance. In this study, the potential of one of the lead-free PIMs, Cesium antimony chloride iodide (Cs3Sb2ClxI9-x), is explored for IPV devices. Recent experimental research work on a Cs3Sb2ClxI9-x− based solar cell with a power conversion efficiency (PCE) of 3.7% is considered for the baseline model development. The device performance is further optimized by investigating 1) absorber thickness and defect density, 2) band alignment of Electron Transport Layer (ETL)/Absorber, ETL Doping concentration and absorber/ETL interface defect density, 3) band alignment of Hole Transport Layer (HTL)/Absorber, HTL Doping concentration, and absorber/HTL interface defect density, 4) work function of metal contacts, 5) series and shunt resistances. After device optimization, the simulated device under 1000 lux WLED is able to achieve Jsc, Voc, FF, and PCE of 1.8 mA cm−2, 1.46 V, 89.3%, and 45.05%, respectively. Further, an evaluation of the performance of the optimized device under various indoor light sources, including White Light Emitting Diode (WLED), halogen, and Compact Fluorescent Lamp (CFL), is conducted in order to assess its performance under widely utilized lighting conditions. © 2024 Wiley-VCH GmbH.Item Comprehensive Modeling of High-Performance All-Inorganic Cs2TiBr6-Based Perovskite Solar Cells(John Wiley and Sons Inc, 2024) Kumar, S.; Thiyyakkandy, J.; Yadav, A.K.; Vinturaj, V.; Garg, V.; Prabhu, S.; Pandey, S.K.The perovskites are desirable materials for photovoltaic and other renewable green energy technologies. Lead-based perovskite solar cells (PSC) have recently gained considerable attention due to the abrupt rise in power conversion efficiency, but lead's well-known toxicity prevents its large-scale commercialization. One compelling option is Cs2TiBr6, which offers a nontoxic alternative. Herein, the electronic and optical characteristics of Cs2TiBr6 absorber material using density functional theory employing the WIEN2K tool are investigated. The energy band structure of Cs2TiBr6 shows an indirect bandgap of 2.2 eV. Additionally, optical properties are calculated, and the suitability of this material as an absorber for indoor and outdoor photovoltaic devices is investigated. The Cs2TiBr6 material has a peak absorption coefficient of 39.57 × 104 cm−1 and optical conductivity of 1.98 × 1015s−1, demonstrating its suitability as an absorber material. After that, a PSC is modeled using SCAPS-1D by using the computed parameters. The performance of the modeled perovskite is enhanced by optimization of various parameters, resulting in the achievement of a high-performance Cs2TiBr6-based PSC, boasting a power conversion efficiency of 19.9% for air mass AM1.5 G spectra and power conversion efficiency of 16.76% for light emitting diode and 17.18% for incandescent light for indoor light conditions. © 2024 Wiley-VCH GmbH.Item An Intricate Balance of Ionicity and Covalency: Metal-Like Conduction in All-Inorganic Halide Double Perovskite Cs2AgSbCl6(American Chemical Society, 2025) Kalyani, M.; Ananthram, K.S.; Saha, S.; Ninawe, P.; Tarafder, K.; Ballav, N.Halide perovskites have recently evolved as attractive materials with enormous technological significance due to synthetic control over the structure-property relationship. Halide perovskites are often realized to be either electrical insulators or semiconductors. We present an unusual metal-like conduction (thermally deactivated) in a Pb-free all-inorganic halide double perovskite, Cs2AgSbCl6. The experimental results were understood using density functional theory studies, combined with molecular dynamics simulations and electron localization function calculations, revealing retention of the predominant ionicity of the Ag-Cl bond and an increase in the covalency of the Sb-Cl bond at an elevated temperature, which resulted in a significant change of the electronic band structure, including the density of states, thereby exhibiting an intricate balance of ionicity and covalency. A significant modulation of the electrical conductivity (more than 3 orders of magnitude) without any noticeable structural change will stimulate the investigation of hitherto unknown electronic phase transitions in halide double perovskites. Additionally, light-induced unidirectional rectification of current in Cs2AgSbCl6 was ascribed to a dynamic internal polarization effect. © 2025 American Chemical Society.Item Ge-doped 3D flower-like Cu2SnS3 structures for enhanced lithium-ion storage performance(Elsevier Ltd, 2025) Appu, S.; Anusha, B.R.; Udayabhanu; Muhiuddin, M.; Rahman, M.R.; Kalappa, K.Development of advanced anode materials with high capacity and stable cycling performance is crucial for next-generation lithium-ion batteries. In this work, we report Ge-doped three-dimensional flower-like Cu2SnS3 (Ge-CSS) microstructures synthesized via a solvothermal route. The introduction of Ge into the Cu?SnS? lattice effectively enhances electrical conductivity and lithium-ion transport, leading to superior electrochemical properties. The Ge-CSS electrode delivers a high initial discharge capacity of 796 mAh/g at 0.1 A/g with improved cycling stability, retaining 354 mAh/g after 100 cycles, and exhibits excellent rate capability, maintaining 74.09 % capacity as the current density increases from 0.1 to 2 A/g. Moreover, the reduced charge transfer resistance compared to undoped Cu2SnS3 highlights the beneficial role of Ge incorporation. These findings demonstrate the potential of Ge-CSS microstructures as a promising anode material for high-performance lithium-ion batteries. © 2025 Elsevier Ltd