Buried and Bulk Synergistic Engineering Enable High-Performance Inverted 2D/3D Perovskite Solar Cells

Abstract

Crystal growth regulation play a key role for fabrication high-quality perovskite films. While surface defects have been extensively studied, optimization of the buried interfaces and bulk properties remains a significant challenge due to their complex influence on film morphology and device performance. Here, a synergistic strategy was developed to improve perovskite film quality by modifying the buried interface with FuMACl and controlling bulk crystallization using (DFP)2PbI4 2D perovskite crystal seeds. The FuMACl layer improves the wettability, alleviate residual stress at the buried interface, and passivate defects. Combined the (DFP)2PbI4 seeds in bulk, these modifications effectively enhance film quality and increase grain size, leading to a significantly reduced defect density. Compared to the control device with an efficiency of 23.11%, the target device demonstrated a champion efficiency of 26.03% and a very notable fill factor of 86.79%, along with improved stability. Moreover, perovskite mini-modules with an aperture area of 10.80 cm2 reached 22.89% efficiency. These findings highlight the potential of synergistic effects of buried interfaces and bulk engineering strategy to significantly enhance the performance of PSCs.