Compatibility of Al-doped ZnO electron transport layer with various HTLs and absorbers in perovskite solar cells

Perovskite solar cells (PSCs) have shown a significant improvement in cell performance in photovoltaics technology. The commonly used light absorbing material of halide-based perovskite in PSCs has produced high efficiency cells with low cost and a simple fabrication process. However, it contains the harmful substance of Pb, which affects the environment, and the cell still suffers from instability in the long run. Therefore, this work presents a theoretical study of the Pb-free absorber layer of CH₃NH₃SnI₃ that is paired for compatibility with various types of hole transport layers (HTLs). Several key parameters of the absorbent layer and HTL have been optimized to produce the highest power conversion efficiency (PCE) using 1D-SCAPS software under AM 1.5 illumination. It was found that the combination of Cu₂O and CH₃NH₃SnI₃ used as the HTL and absorbent layer, respectively, has resulted in great PCE as high as 27.72%. These findings prove that the use of inorganic HTLs and Pb-free perovskite layers is promising for use in PSCs.