Boosting efficiency of eco-friendly perovskite solar cell through optimization of novel charge transport layers

Formamidinium tin triiodide (FASnI3) is a suitable candidate for the absorber layer in perovskite solar cells (PSC) because of its non-toxicity, narrow band gap, thermal stability and high carrier mobility. This study focuses on the analysis and improvement in the performance of FASnI3-based PSCs using various inorganic charge transport materials. The copper-based materials such as Cu2O, CuAlO2, CuSCN and CuSbS2 are introduced as hole transport layers due to their earth abundance, ease of manufacturing, high charge mobilities and chemical stability. Similarly, fullerene derivates (PCBM and C60) are deployed as electron transport layers due to their mechanical strength, thermal conductivity and stability. The effect of these materials on optical absorption, quantum efficiency, energy band alignment, band offsets, electric field and recombination are studied in detail. The reasons for the low performance of the cell are identified and improved through design optimization. The PSC performance is analysed in both inverted and conventional architecture. Among all the structures, the best result is achieved through ITO/CuSCN/FASnI3/C60/Al with an efficiency of 27.26%, Voc of 1.08 V, Jsc of 29.5 mAcm-2 and FF of 85.6%.