Device modelling and optimization of various n-i-p configurations for MASnI3 perovskite solar cells to achieve high efficiency using Solar Cell Capacitance Simulator-1D

Abstract

Perovskite materials are potential light harvesters, and in specific tin-based absorbers such as methyl ammonium tin iodide (MASnI3) are non-toxic with distinguished optoelectronic properties. This is the first simulation report to explore the application of strontium titanate (SrTiO3) as an electron transport layer (ETL) in planar n-i-p MASnI3 perovskite solar cell (PSC) device. In an attempt to enhance the output performance of MASnI3 PSCs, a systematic approach is devised to determine appropriate alternative charge-selective materials via solar cell capacitance simulator (SCAPS-1D) software. The significance of varying thickness, donor doping concentration, acceptor doping concentration, defect density, diffusion length, and energy band offset for the reference PSC configuration TiO2/MASnI3/Spiro-OMeTAD are investigated. The optimized reference structure delivered 19.72% efficiency. In pursuit of high photovoltaic performance, seven different electron transport materials were comparatively examined. As a result, PCBM, In2S3, and CeO2 were considered not suitable due to their limited electrical performance. Consequently, seven inorganic hole transport layers (HTL) along with four suitable ETL were utilized in MASnI3 PSC to construct twenty-eight novel n-i-p device structures whose efficiency ranges between 14.20% and 22.77% respectively. The influence of varying the work function of back contact, series resistance, shunt resistance, and temperature on the photovoltaic parameters was analysed. The vital parameters investigated in this simulation for implementing state-of-the-art PCS are energy band offset, diffusion length, activation energy, recombination current profile, and built-in-potential. The device configuration featured with SrTiO3/MASnI3/CuO and SrTiO3/MASnI3/MASnBr3 achieved a maximum efficiency of 22.77% and 22.60%, respectively. The PSC tailored with SrTiO3 have better thermal stability and enhanced fill factor, which accounts for improving the output power. These novel findings of all-inorganic PSC will provide preliminary support for practical implementation.