Optimizing band gap, electron affinity, & carrier mobility for improved performance of formamidinium lead tri-iodide perovskite solar cells

Perovskite solar cells (PSC) offer the advantage of tunable nature, allowing for the adjustment of cell design parameters to enhance performance. This study focuses on the crucial role of tuning band gap, electron affinity, carrier mobility, thickness, and doping in improving the performance of Formamidinium lead tri-iodide (FAPbI3) PSCs. The PSC structure incorporates two carbon allotropes, PCBM and C60, as electron transport layers (ETLs), in conjunction with copper-based materials (CuAlO2, CuI, Cu2O) as hole transport layers (HTLs) to leverage their exceptional thermal and electrical conductivity. Using SCAPS-1D, six distinct PSC structures with various combinations of ETLs and HTLs are analyzed. The investigations employ continuity and Poisson equations to explore the impact of the design parameters on PSC performance. Additionally, a comprehensive assessment is conducted to evaluate energy band alignment, band offset, electric field distribution, recombination and defects. Through meticulous investigations, the study identifies the optimal combination of Cu-HTL and C-ETL that yields exceptional PSC performance. Specifically, employing CuAlO2 as the HTL and PCBM as the ETL achieves remarkable results, with a high PCE of 26.49 %, a Voc of 1.25 V, a Jsc of 23.51 mA/cm2, and an FF of 89.49 %.