Numerical Analysis of Novel Cs₂AuBiCl₆-Based Double Perovskite Solar Cells with Graphene Oxide as HTL—A SCAPS-1D Simulation

Perovskite solar cells (PSCs) are promising candidates to address today’s energy crisis. The most challenging obstacles to the commercialization of PSCs are their volatility toward environmental conditions and the presence of lead (Pb). To solve this, the scientific community has come up with double perovskites having a general molecular formula of A₂BB′X₆. In this study, we introduce a novel structure Cs₂AuBiCl₆ as an absorber due to its non-toxic nature and stable performance. Also, the electron transport layer (ETL) and hole transporting layer (HTL) play key roles in the performance and stability of PSCs. But most of the widely used HTL and ETL materials are very costly and have complex synthesizing process. Here, we use a novel HTL material graphene oxide (GO) as HTL and ZnSe as ETL, both of them being cheap, non-toxic, and easily available. We investigate for the first time ever the performance of a ZnSe/Cs₂AuBiCl₆/GO structure using the Solar Cell Capacitance Simulator (SCAPS-1D) software. Results indicate that the optimized thickness was 1 μm for absorber and 0.1 μm for HTL. The device efficiency improved with increasing the shunt resistance to 50 Ω, while it deteriorated with series resistance. Finally, all the output parameters declined with the rise in the operating temperature beyond 300 K. The elicited results suggest that Cs₂AuBiCl₆ and GO can play a momentous role in achieving highly efficient lead-free, inorganic perovskite solar cells.