Optimizing Geometry and ETL Materials for High-Performance Inverted Perovskite Solar Cells by TCAD Simulation

Due to the optical properties of the electron transport layer (ETL) and hole transport layer (HTL), inverted perovskite solar cells can perform better than traditional perovskite solar cells. It is essential to compare both types to understand their efficiencies. In this article, we studied inverted perovskite solar cells with NiO_x/CH₃NH₃Pb₃/ETL (ETL = MoO₃, TiO₂, ZnO) structures. Our results showed that the optimal thickness of NiO_x is 80 nm for all structures. The optimal perovskite thickness is 600 nm for solar cells with ZnO and MoO₃, and 800 nm for those with TiO₂. For the ETLs, the best thicknesses are 100 nm for ZnO, 80 nm for MoO₃, and 60 nm for TiO₂. We found that the efficiencies of inverted perovskite solar cells with ZnO, MoO₃, and TiO₂ as ETLs, and with optimal layer thicknesses, are 30.16%, 18.69%, and 35.21%, respectively. These efficiencies are 1.5%, 5.7%, and 1.5% higher than those of traditional perovskite solar cells. Our study highlights the potential of optimizing layer thicknesses in inverted perovskite solar cells to achieve higher efficiencies than traditional structures.