Computational Evaluation of Lead Free MoSe₂-Based Thin Film Solar Cell for Enhanced Photovoltaic Performance

Seeking a sustainable and ecologically friendly alternative to lead-based solar cells (SCs), this study explores Molyb-denum Diselenide <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(MoSe₂)</tex> as a promising absorber material by leveraging its compelling structural, electrical and optical features to improve SC efficiency. Initial analysis via Density Functional Theory (DFT) using CASTEP software revealed <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">MoSe₂</tex> 's bandgap at 1.22 e V, aligning closely with experimental values. Building upon this fundamental understanding, a novel device architecture is proposed encompassing Mo <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Se₂</tex> as the absorber layer, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V₂O₅</tex> as the hole transport layer (HTL), WS <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> as the electron transport layer (ETL) and FTO as the transparent conductive oxide (TCO). Various parameters, including absorber layer thickness and doping density, parasitic resistance, temperature, back contact and bragg reflector were systematically altered to evaluate their influence on the photovoltaic parameters using SCAPS-ID. This simulation reveals open-circuit voltage <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(Voc)</tex> of 0.88 V, short-circuit current density <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(Jsc)</tex> of 42.80 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mA/cm²</tex> , fill factor (FF) of 85.53 % and an impressive power conversion efficiency (PCE) of 32.01 %. These findings demonstrate Mo <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Se₂</tex> 's potential as a safer and more productive material for solar cell applications, shedding light on ways to optimize solar cell design for better performance.