界面钝化与能级调控工程增强Cs2TiBr6钙钛矿太阳能电池的载流子传输：第一性原理计算与SCAPS分析

Abstract Cs 2 TiBr 6 perovskite is considered an ideal substitute for lead-based materials in the field of perovskite solar cells (PSCs) due to its environmental stability. However, its power conversion efficiency (PCE) remains inadequate. Ameliorating carrier transport is critical to the photovoltaic performance of PSCs. In this study, based on experimental design, we constructed energy level offset structure PSCs with a C 60 interface passivation layer, and conducted systematic research using SCAPS-1D (Solar Cells Capacitance Simulator) and first-principles. It was indicated that the CBTS/Cs 2 TiBr 6 energy level offset structure provided a favorable carrier transport path, thereby reducing the recombination of photogenerated holes and electrons within the device and improving carrier separation efficiency. Further comprehensive analysis from the perspectives of Nyquist impedance, energy band structure, carrier recombination rate, built-in electric field distribution, etc., revealed the impacts of C 60 interface passivation, defect density, thickness, and operating temperature on PSCs. It was found that the C 60 interface passivation layer further optimized the interface transport characteristics and built-in electric field distribution of PSCs, promoting carrier movement between layers. Additionally, first-principles calculations were utilized to investigate the perovskite layer’s structural, optical, and electronic properties. Ultimately, the optimized PSCs achieved an outstanding PCE of 27.78 % in the proposed structure (FTO/Cs 2 TiBr 6 /C 60 /CBTS/Au), which is 12.8 times higher than the efficiency of the initial experimental structure. This study provides a novel pathway for achieving lead-free, high-efficiency Ti-based PSCs.