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

Formamidinium tin triiodide (FASnI) 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 FASnI-based PSCs using various inorganic charge transport materials. The copper-based materials such as CuO, CuAlO, CuSCN and CuSbS 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 C) 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/FASnI/C/Al with an efficiency of 27.26%, of 1.08 V, of 29.5 mAcm and FF of 85.6%.