CsPbBr3 Quantum Dots‐Sensitized Mesoporous TiO2 Electron Transport Layers for High‐Efficiency Perovskite Solar Cells

Abstract

The carrier transport layer plays a critical role in high efficiency and stable perovskite solar cells (PSCs). Herein, CsPbBr3 quantum dots‐sensitized mesoporous TiO2 (CPB–TiO2) electron transport layer for fabricating high‐quality perovskite films with enhanced phase stability is developed. The CPB–TiO2 layer enhances the perovskite crystallinity, phase stability, and reduces the nonradiative carrier recombination in PSCs. As a result, the CPB–TiO2 significantly improves the power conversion efficiency of FAPbI3 PSCs from 23.11% to 24.46% and reduces the device hysteresis. The CPB–TiO2–FAPbI3 device shows enhanced stability, retaining 90% of its initial efficiency after 500 h operation at maximum power point tracking under 1 sun illumination, whereas the control device degrades to 80% of initial performance in the first 200 h. In addition, this strategy is applicable to CsPbI3 perovskite, which provides a new and general strategy for preparing high‐efficiency PSCs.