A comprehensive study on RbGeI3 based inorganic perovskite solar cell using green synthesized CuCrO2 as hole conductor

Though perovskite solar cell (PSC) is achieving an immense 25.7 % efficiency within a few years of extensive research, a shorter life span with organic part and charge transporting layers hinders their commercialization. So, inorganic perovskite aligned with the hole transporting layer (HTL) could be an alternative to achieve long-term device stability. The delafossite, CuCrO2 was prepared by the green synthesized method and then characterized. According to the X-ray diffraction (XRD) pattern, the crystallites are polycrystalline phases, and the average crystallite size is 159.3 nm. Spectrophotometric measurement was used to determine the bandgap (Eg), which is 3.0 eV. These results are applied for simulation study in Pb-free RbGeI3-based inorganic perovskite device using CuCrO2 as HTL. HTL thickness, diffusion length, interface defect, carrier concentration, activation energy, and temperature effects on the device performance have been explored by SCAPS-1D simulation software. In the optimized condition, the simulated result shows the maximum device efficiency is 23.8 %, corresponding open circuit voltage (Voc), short circuit current density (Jsc) and fill-factor (FF) of 0.89 V, 33.7 mA cm−2, and 79.2 %, respectively. A study of activation energy for the device elucidates that the significant recombination is Shockley Read Hall (SRH) type at the (RbGeI3/CuCrO2) interface layer. The result of temperature impact has supported better thermal stability. Indium tin oxide (ITO) is suitable front contact for the proposed p-i-n structure. The study reveals that the delafossite, CuCrO2 can be a potential HTL for Pb-free inorganic perovskite solar cells.