Browsing by Author "Sarkar, Joy"

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    Electronic Band Structure and Density of States Analysis of Electron Transport Materials for Perovskite Solar Cells
    (University of North Bengal, 2021-01) Sarkar, Joy; Biswas, Rajat; Chatterjee, Suman
    For investigating the atomic-scale calculation of perovskite solar cells (PSCs), a detailed model of interaction between the electrons and the junctions is very essential. Such atomicscale level analysis is based on the quantum mechanical model. Therefore we need a Schrödinger equation which involves all the electrons with the associated junction potential. Here we consider the Schrödinger equation and solving it by full-potential linearized augmented plane wave (LAPW) method in Wien2k code through the Density Functional Theory (DFT). We have used generalized gradient approximation (GGA) given by Perdew-Burke-Ernzerhof (PBE) for the electronic band structure and Density of States (DOS) calculation of TiO2 and ZnO which are used in perovskite solar cell as the electron transport layer. We obtained the value of the energy bandgap as ~2.934 eV for TiO2 and ~3.119 eV For ZnO. We also determined the value of Fermi energy for both of the material. Finally, we compare the transport properties of TiO2 and ZnO by analyzing their band structure and DOS diagrams.
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    Improvement of Photovoltaic Performance of Dye Sensitized Solar Cells by Pre-Dye Treating of Zno Nanoparticles
    (University of North Bengal, 2021-01) Biswas, Rajat; Sarkar, Joy; Chatterjee, Suman
    Dye sensitized solar cells (DSSC) were fabricated using Rose Bengal dye. Pure and pre-dye treated Zinc oxide (ZnO) nanoparticles were used to fabricate the photoanodes of two cells. The structural characteristics of ZnO nanoparticles were studied using X-ray diffraction analysis and the surface morphology by Scanning electron microscopy. The absorption property of the dye was studied using UV-VIS spectra. The pre-dye treatment has improved the properties of ZnO, such as reduced agglomeration, improved morphology, increased dye adsorption and reduced dye aggregation. Photovoltaic parameters like short circuit current density (JSC), open circuit voltage (VOC), fill factor (FF) and overall energy conversion efficiencies (η) for the conventional and pre-dye treated ZnO based fabricated cells were calculated to be 3.73 mA/cm2, 0.53 V, 0.63 and 1.26 % and 4.47 mA/cm2, 0.55 V, 0.62 and respectively. The pre-dye treated DSSC showed an improvement in short circuit current density (Jsc) by 19.84% and efficiency (η) by 21.43 %.
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    Relation between stock market and select marco-electronic variables : A study on pre and post liberalization experiences in India
    (University of North Bengal, 2022) Sarkar, Joy; Ray, Hirak; Dhar, Samirendra Nath