Proton Transfer Complex-Confined Self-Assembled Monolayer for Thermally Stable Inverted Perovskite Solar Cells
Bin Zhou, Shasha Wang, Duo Qu, Ruilin Han, Hongkang Fu, Haonan Sun, Yanju Wang, Chuanzhen Shang, Chenyun Wang, Wenying Zhao, Jingyuan Qiao, Xiaoli Gong, Lei Zhang, Jiangang Liu, Xiaoyu Yang, Huei Min Chua, Wei Lin Leong, Yongguang Tu, Wei HuangAbstract
Carbazole-derived hole-selective self-assembled monolayer (SAM) contacts are indispensable for high-performance inverted perovskite solar cells. Nevertheless, self-aggregation and molecular desorption of SAM result in a fragile heterogeneous interface, severely hindering device reproducibility and stability. Here, we propose a proton transfer complex-confined strategy to address the interfacial spatial heterogeneity, thereby enhancing the dispersion and adsorption of SAMs. This achieves a multi-site coupling design at the buried interface, effectively preventing interface destabilization by thermal stress. Consequently, a champion efficiency of 26.23% is achieved, with an impressive fill factor (85.64%). These devices resist thermal degradation at 75 °C for 1368 h. Notably, the potential difference change of the target SAMs after thermal degradation at 150 °C is only 5.9 mV, confirming its interfacial chemical stability. The corresponding perovskite film withstands 100 thermal stress cycles (–60 °C ∼ 85 °C). This strategy also achieves higher photovoltaic performance at a lower temperature (240 K).