Interface layer modulation of an all-inorganic perovskite solar cell to study the carrier transport mechanism

Abstract

Over the past decade, organic halide perovskite has been an excellent absorber in solar cells. However, their stability issues have forced the research community to search for purely inorganic perovskites. In this work, we designed a perovskite solar cell based on a purely inorganic Cs0.8Rb0.2SnI3 absorber layer with inorganic carrier transport layers using SCAPS-1D simulation software. Using this exemplary architecture, we have discussed different carrier movement mechanisms in the conduction and valence bands through the interfaces of the absorber and carrier transport layers by instigating two interface layers. Our results illustrate the variation in device performance with the electron affinities and diffusion lengths. In addition, the study demonstrates a positive impact of Rb doping in CsSnI3 based perovskite solar cells. The absorber thickness and defect density optimization are also executed to maximize the solar cell performance. The optimized electron affinities of the interface layers are found to be 4.1 and 4.3 eV, respectively. The final model of the device has achieved a photo-conversion efficiency of 23% with a short circuit current of about 30 mA cm−2. The optimized model covers the entire visible solar spectrum with a quantum efficiency of >90%.