Optimization of Electron Transport Layer-Free Cs2TiBr6/MASnBr3 Laminated Structure Perovskite Solar Cells by SCAPS-1D Simulation

Cs2TiBr6 materials have promising applications in organic-inorganic halide perovskite solar cells (PSCs), but their power conversion efficiency (PCE) is low. Herein, based on the matching band structure of MASnBr(3) and Cs2TiBr6, a no-electron transport layer (ETL)-structured laminated PSC is constructed for numerical simulation using SCAPS-1D. The results have shown that the ETL-free structure reduces the potential barrier between the interfaces and improves the performance of the device. MASnBr(3) is used to replace the traditional hole transport layer to form a laminated structure, which is more conducive to the built-in electric field of the device. Through exploring the internal influencing factors and applicable environment, it is found that the device can maintain a good operating level between 230 and 430 K. Finally, the best PCE of 19.63% is achieved in the proposed device structure (FTO/Cs2TiBr6/MASnBr(3)/Au). This work provides a new approach to achieving lead-free and efficient laminated PSCs in a wide temperature range of usage environments from -43 to 157 degrees C.