Theoretical insights into lead-free planer Cs₂AuBiCl₆ based double perovskite solar cells with various charge transport layers via numerical analysis

To address the environmental and public health concerns arising from the release of lead toxins into the air and water, it is crucial to consider alternatives to lead-based perovskite solar cells (PSCs). Lead-free perovskite materials present themselves as a promising candidate for photovoltaic applications. This study investigates the potential of Cs₂AuBiCl₆, a lead-free perovskite, as a substitute for lead-based perovskite materials in solar cells. This double perovskite material exhibits notable advantages, including a high absorption coefficient, less reflectivity, and an optimal bandgap of 1.12 eV, making it more promising for efficient solar cell applications. Various organic-inorganic Hole transport layers (HTLs) including SWCNT, Cu₂Te, PTAA, MoO₃, GaAs, Carbon, MoS₂, C6TBTAPH₂, NiCo₂O₄, C₆TBTAPH₂ and different Electron transport layers (ETLs) like CdZnS, ZnO, ZnSe, PC₆₀BM are used to explore Cs₂AuBiCl₆ based PSC in this study. A total of ten different combinations of device structures are explored throughout this study where numerous device parameters like thickness, defect density, donor density, and acceptor density are optimized. After optimization of device parameters, all of the devices have continuously attained far greater efficiency levels. Out of all these combinations, the device structure with a ZnSe ETL and Cu₂Te HTL achieves the highest PCE of 32.36 %. The effect of JV characteristics, series and shunt resistance, generation, and recombination rate are also observed in this study. All the simulations of this study are carried out with SCAPS-1D software. This study suggests that Cs₂AuBiCl₆ double perovskite material can play a pivotal role in the field of solar cell technology as an efficient absorber layer.