Effects of co-doping the SnO2 electron transport layer with boron and indium on the photovoltaic performance of planar perovskite solar cells

Abstract

We have used a solution-based approach to incorporate boron (B) and indium (In) dopants into the conventional SnO₂ electron transport layer (ETL) to create high-performing planar perovskite solar cells (PSCs). By adding B and In in precise stoichiometric ratios to the standard SnO₂ precursor solution, we achieved a PCE of 20.05% compared to the PCE of 18.36% seen in devices having an undoped SnO₂ ETL. The addition of BIn to the SnO₂ ETL resulted in enhanced transparency and conductivity, resulting in higher current density (J_sc) and fill factor (FF) in PSCs. Furthermore, due to the improved energy level alignment and lower work function of BIn–SnO₂, higher V_oc is also observed. Furthermore, the long-term stability of PSCs is significantly improved with the incorporation of the BIn-doped SnO₂ ETL.