Enhanced efficiency of indoor photovoltaic using compositionally graded Cs₂AgBi_1-xSb_xBr₆ perovskite

This study investigates the photovoltaic performance of a lead-free double perovskite FTO/BaSnO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> /Cs<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>AgBi<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.75</inf>Sb<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.25</inf>Br<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf>/CuO/Au solar cells under different white LED (WLED) lighting conditions for indoor PV applications. The performance of graded and non-graded light harvesters (LH) is comparatively analyzed using the PSC structure. The study utilizes SCAPS-1D simulations to optimize device architecture and evaluate the influence of LH thickness, doping, defect densities, and operating temperature. The findings demonstrate that the graded and non-graded LH configurations achieve a remarkable efficiency of 42.80% and 33.53% respectively at LH thickness of 400nm and bulk defect density of 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">14</sup> cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup> under 7500 K color temperature. Additionally, the quantum efficiency of graded device delivers a wider range of wavelength compared to non-graded counterparts. This work underscores the potential of lead-free double perovskites for high-efficiency indoor photovoltaics, paving the way for sustainable applications in self-powered and energy-harvesting systems.