Simulation of MASnI3-based inverted perovskite solar cells with double hole transport layers and an electron transport layer

A model of CH3NH3SnI3 (MASnI3)-based inverted perovskite solar cell (PSC) with double hole transport layers (HTLs) and an electron transport layer (ETL) was established, and the device was studied using solar capacitance simulator (SCAPS). Compared with a single HTL, the double HTLs of CuI/MoO3 can improve device performance significantly. Among six ETLs, WS2 has been found to be the best ETL. Then, the effects of absorber layer thickness, CuI/MoO3 thickness, the defect density and doping density of the absorption layer, and metal electrode work function on device performance have been investigated in detail. According to the simulation results, the optimum thickness of MASnI3 is 500 nm, and the both CuI and MoO3 layers should be as thick as 20 nm. To achieve the ideal efficiency, the defect density of the absorption layer should be as low as 1 × 1014 cm−3, and its doping density should be 1 × 1016 cm−3. Moreover, the metal work function should be less than 4.42 eV to avoid the formation of a Schottky barrier at the WS2/metal interface. After optimization, the device can reach the highest efficiency of 28.13%. Our simulation results will help advance the manufacturing of high-performance Pb-free perovskite solar cells in the future.