Simulated development and optimized performance of CsPbI3 based all-inorganic perovskite solar cells

Cesium lead iodide (CsPbI3), as one promising inorganic halide perovskite for higher stability, has received extensive attention in recent years. However, CsPbI3 based perovskite solar cells (PSCs) have yet to realize the high efficiency achieved in organic-inorganic hybrid PSCs. In this work, we perform a device modeling by SCAPS-1D to investigate the limitation of CsPbI3 all-inorganic PSC (CsPbI3 i-PSCs) and improve its performance. For i-PSC, not only the absorber but all the layers should be composed of inorganic materials only. Therefore, several potential inorganic hole and electron transport layers (i-HTL and i-ETL) are compared firstly and the results reveal that Cu2O HTL and SnO2 ETL are the most suitable materials among them. Moreover, the device performance is further improved by optimizing the work function of back electrode, absorber thickness, doping density as well as defect density. Under optimized conditions, a conversion efficiency of 21.31% is obtained for the FTO/SnO2/CsPbI3/Cu2O/Au i-PSC, indicating that there is much room for further performance enhancement.