Optimization of mixed valence Cs₂Au₂I₆-based double perovskite solar cells by SCAPS-1D simulation

Within the realm of photovoltaics (PVs), perovskite solar cells (PSCs) have garnered substantial interest as a result of their cost-effective production methods, high power conversion efficiency (PCE), and adaptable implementation designs. Nevertheless, the environmental sustainability and toxicity of lead (Pb)-based materials in PSCs present challenges. In the ongoing pursuit of superior PV materials, this study examines the PV potential of the all-inorganic mixed-valence Cs₂Au₂I₆ double perovskite (PVK). By applying the solar cell capacitance simulator-one dimensional (SCAPS-1D), a comprehensive simulation analysis is performed. The PV properties are assessed by modifying the bulk defect density (N_{t, bulk}), doping levels, layer thicknesses, and HTL/PVK and PVK/ETL interface defects. The performance of Cs₂Au₂I₆ PSCs is additionally assessed in terms of temperature, metal work function, and series and shunt resistance. The results unequivocally indicate that the proposed PSC, which utilizes Cu₂O as the hole transport layer (HTL) and TiO₂ as the electron transport layer (ETL), exhibits an exceptional PV efficiency. The simulated PSC achieves a fill-factor (FF) of 84.52 %, a short-circuit current density (J_SC) of 31.77 mA/cm², and an open-circuit voltage (V_OC) of 1.11 V, and an efficiency of 29.88 % after optimizing the device parameters. This systematic computational analysis offers valuable insights and establishes a workable future path for the development of Cs₂Au₂l₆-based solar cells.