Inorganic Lead-Free Cs2AuBiCl6 Perovskite Absorber and Cu2O Hole Transport Material Based Single-Junction Solar Cells with 22.18% Power Conversion Efficiency

Cs2AuBiCl6 is considered to be a potential lead-free double perovskite alternative for perovskite solar cells. Its electronic and optical properties are investigated using density functional theory. The electronic properties of Cs2AuBiCl6 material ensure a bandgap of 1.40 eV (without considering SOC) and 1.12 eV (with SOC) using mBJ exchange-correlation functional, close to the optimal bandgap for solar cell application as per the Shockley-Queisser limit. Optical properties suggest a high absorption coefficient approximate to 10(5) cm(-1) with low reflectance, making it the optimal absorber material. Furthermore, the photovoltaic performance of Cs2AuBiCl6 based single-junction transparent conducting oxide (TCO)/IDL1/Cs2AuBiCl6/IDL2/Cu2O solar cell is investigated using SCAPS-1D device simulation program. The impact of electron affinity, thickness, carrier concentration, defect density, and interface defect density is examined using interface defect layer (IDL) on the photovoltaic performance. The maximum photoconversion efficiency (PCE) of approximate to 22.18% is noticed for optimized material's parameters. These studies on TCO/IDL1/Cs2AuBiCl6/IDL2/Cu2O solar cell will provide guidelines for designing and developing an efficient lead-free perovskite-based solar cell as an alternative to conventional halide perovskite materials based solar cell.

Automated summary

Cs2AuBiCl6 is considered a potential lead-free double perovskite alternative for perovskite solar cells due to its electronic and optical properties close to the optimal bandgap. The solar cell based on Cs2AuBiCl6 shows high absorption coefficient and optimal absorber material characteristics, achieving a maximum photoconversion efficiency of approximately 22.18% after optimizing material parameters.