High-Performance Lead-Free Bifacial RbGeBr ₃ Perovskite Solar Cell: A SCAPS-1D Numerical Study

Perovskite solar cells (PSCs) were identified as the future of photovoltaics owing to their adjustable bandgap, superior optoelectronic characteristics, and low manufacturing expenses. Lead-free perovskites were considered less hazardous, more stable, and more flexible alternatives to conventional lead-based perovskites. In this paper, RbGeBr3 was modeled in the SCAPS-1D simulator to optimize the inorganic PSC as the photoactive layer. To find the optimized solar cell, different types of Electron Transport Layer (ETL) and Hole Transport Layer (HTL) were used. The initial optimized configuration without an HTL achieved a power conversion efficiency (PCE) of 19.51%. Upon incorporating graphene oxide (GO) as the HTL, an efficiency of 25.61% was attained by the final optimized device configuration, with a VOC of 1.18 V and…