Highly efficient lead-free ethyl ammonium substituted perovskite solar cell simulated using SCAPS 1D

This computational study investigated a lead (Pb)-free ethyl ammonium (EA) substituted ethylenediamine (EDA) based ((FA0.9EA0.1)0.98EDA0.01SnI3) perovskite solar cell (PSC) using the solar cell capacitance one-dimensional simulator (SCAPS 1D). The initial device schematic comprised ((FA0.9EA0.1)0.98EDA0.01SnI3) based perovskite as an absorber layer with copper (I) oxide (Cu2O) and [6,6] phenyl-C61 butyric acid methyl ester (PCBM) as hole and electron transport layers, where the device efficiency was 21.87%. The impacts of numerous electron transport layers (ETLs) and hole transport layers (HTLs) were also examined. The charge transport layers were optimized based on their energy levels and according to the relationship between the built-in potential (Vbi) and the open-circuit voltage (VOC). Numerical simulations showed that to circumvent the Vbi loss, the valence band (VB) maximum of HTL (EVB_HTL) should not be lower than the VB for perovskite (PVK) (EVB_PVK) for the appropriate selection of HTLs. Correspondingly, for the suitable selection of ETLs, the conduction band (CB) minimum of ETL (ECB_ETL) and the front contact should not be greater than the CB minimum for PVK (ECB_PVK). Therefore, the optimized ETLs and HTLs were obtained as zinc oxysulfide and copper (II) phthalocyanine, respectively, where the device's efficiency increased up to 22.36%. The effect of the thickness of the EDA-based PSCs was also examined and the optimized thickness was obtained as 1.1 μm, where the device's efficiency increased to 24.42%. This improvement in the performance of the device indicates that EA substituted EDA-based ((FA0.9EA0.1)0.98EDA0.01SnI3) PSC is a promising alternative for use in Pb-free PSCs.