DFT and SCAPS-1D based optimization study of double perovskite Cs2AuBiCl6 solar cells utilizing different charge transport layers

Abstract

In this work, halide double perovskite (HDP) Cs2AuBiCl6 is investigated as potential absorber material in the perovskite solar cell (PSC) using the SCAPS-1D tool. WIEN2K code is utilized for computation to study the structural, and optoelectronic properties of Cs2AuBiCl6. The calculated bandgap of the Cs2AuBiCl6 is found to be ∼1.09 eV using TB-mBJ (Tran-Blaha modified Becke-Johnson) potential. Performance of the Cs2AuBiCl6-based PSC is enhanced by improving the properties of charge transport layers and the perovskite (PVSK) absorber layer. Combination of Electron Transport Layers (ETLs) such as WS2, PCBM, ZnO, TiO2, and C60 and Hole Transport Layers (HTLs) such as Cu2O, P3HT, CuSCN, PEDOT: PSS, Spiro-OMeTAD, CuSbS2 are evaluated to find the best ETLs and HTLs among the above-mentioned materials. Also, further study is performed on the five best devices with five different ETLs using CuSbS2 as the HTL. Apart from that, the energy band diagrams of the best five devices are investigated. Further, a performance study is done on those best five devices through the impact of the variations in thickness of ETL, defect density, thickness of Cs2AuBiCl6 layer, shunt, and series resistances of device. After all the optimizations, the best PCEs of these five optimized devices are found to be 21.16 %, 21.14 %, 20.84 %, 20.79 %, and 14.75 % with CuSbS2 as HTL, and C60, WS2, TiO2, PCBM, and ZnO as ETLs, respectively. Furthermore, current density-voltage (J-V) and quantum efficiency (QE) characteristics of the five devices are analyzed to determine the potential of Cs2AuBiCl6 as a viable material for non-leaded PSCs.