Luo Chao, Gao Feng, Wang Xianjin, Zhan Changling, Zhang Xianchen, Zheng Guanhaojie, Zhang Xusheng, Gao Xingyu, He Zhubing, Zhao Qing
State Key Lab for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China.
Shanghai Synchrotron Radiation Facility (SSRF), Zhangjiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, China.
Sci Adv. 2024 Sep 27;10(39):eadp0790. doi: 10.1126/sciadv.adp0790.
Preoptimizing perovskite films may generally improve the performance of the final perovskite solar cells (PSCs). However, the research on whether the film optimization fully contributes to the enhancement of the final PSCs has been long neglected. We demonstrated that the preparation of metal electrodes by high-vacuum thermal evaporation, an unavoidable step in almost all device fabrication processes, will damage the surface of perovskite films, resulting in component escape, defect density rebound, carrier extraction barrier, and film stability deterioration. Therefore, the prepared perovskite film and the final film actually working in devices are not exactly the same, and the contribution of film optimization to the device improvement was weakened. We designed a bilayer structure composed of graphene oxide and graphite flakes to eliminate the unwanted film inconsistencies and thus save the film optimization loss. Therefore, the efficient PSCs with power conversion efficiency of 25.55% were obtained, which demonstrated negligible photovoltaic performance loss after operating for 2000 hours.
预先优化钙钛矿薄膜通常可以提高最终钙钛矿太阳能电池（PSC）的性能。然而，关于薄膜优化是否能完全促进最终PSC性能提升的研究长期以来一直被忽视。我们证明，通过高真空热蒸发制备金属电极这一几乎所有器件制造过程中都不可避免的步骤，会损害钙钛矿薄膜的表面，导致成分逸出、缺陷密度反弹、载流子提取障碍以及薄膜稳定性恶化。因此，制备的钙钛矿薄膜与实际在器件中工作的最终薄膜并不完全相同，薄膜优化对器件性能提升的贡献被削弱。我们设计了一种由氧化石墨烯和石墨薄片组成的双层结构，以消除不必要的薄膜不一致性，从而挽回薄膜优化损失。因此，获得了功率转换效率为25.55%的高效PSC，其在运行2000小时后光伏性能损失可忽略不计。
