Metals doped cesium based all inorganic perovskite solar cells: Investigations on Structural, morphological and optical properties

Organic containing methylammonium and formamidinium lead halide perovskite has emerged as photovoltaic materials for the past few years, but instability of the organic compounds in perovskite has been a major issue with regard to commercial applications. Herein, we present an 'all solid state' planar perovskite solar cells (PSCs) based 'organic-free' CsPbI3 and both 'organic and iodine free' CsPbBr3 perovskite. We have used solid state based copper (I) thiocyanate (CuSCN) as a hole transport material (HTM) in PSCs. Selected metal ions such as 'Sn, In, Cu and Ag' were used as dopant in both CsPbI3 and CsPbBr3 perovskite for reduce toxic lead content. Further, for the first time, by the use of highly stable black phase CsPbI3 film prepared by doping Sn ions with different concentrations, the efficiency of the device increased from 0.75% to 5.12%. Moreover, pure and metal doped CsPbBr3 based PSCs were fabricated and analyzed their structural and photovoltaic performance under the same measurement condition. This research work highlights a process of fabricating solid state PSCs and particularly addresses the effect of metal ion incorporation on the performance of cesium based PSCs.