Wang Rui, Liu Xiaoyu, Yan Shan, Meng Ni, Zhao Xinmin, Chen Yu, Li Hongxiang, Qaid Saif M H, Yang Shaopeng, Yuan Mingjian, He Tingwei
College of Physics Science and Technology, Hebei University, Baoding, 071002, China.
Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing, 100049, China.
Nat Commun. 2024 Oct 16;15(1):8899. doi: 10.1038/s41467-024-53344-9.
Wide-bandgap (WBG) perovskite solar cells (PSCs) are employed as top cells of tandem cells to break through the theoretical limits of single-junction photovoltaic devices. However, WBG PSCs exhibit severe open-circuit voltage (V) loss with increasing bromine content. Herein, inhomogeneous halogen-phase distribution is pointed out to be the reason, which hinders efficient extraction of carriers. We thus propose to form homogeneous halogen-phase distribution to address the issue. With the help of density functional theory, we construct a double-layer structure (D-2P) based on 2-(9H-Carbazol-9-yl)ethyl]phosphonic acid molecules to provide nucleation sites for perovskite crystallization. Homogeneous perovskite phase is achieved through bottom-up templated crystallization of halogen component. The efficient carrier extraction reduces the Shockley-Read-Hall recombination, resulting in a high V of 1.32 V. As a result, D-2P-treated device (1.75 eV) achieves a record power conversion efficiency of 20.80% (certified 20.70%), which is the highest value reported for WBG (more than 1.74 eV) PSCs.
宽带隙（WBG）钙钛矿太阳能电池（PSC）被用作叠层电池的顶电池，以突破单结光伏器件的理论极限。然而，随着溴含量的增加，WBG PSC表现出严重的开路电压（V）损失。在此，指出不均匀的卤素相分布是其原因，这阻碍了载流子的有效提取。因此，我们建议形成均匀的卤素相分布来解决这个问题。借助密度泛函理论，我们基于2-(9H-咔唑-9-基)乙基]膦酸分子构建了双层结构（D-2P），为钙钛矿结晶提供成核位点。通过卤素组分的自下而上模板化结晶实现了均匀的钙钛矿相。有效的载流子提取减少了肖克利-里德-霍尔复合，从而产生了1.32 V的高V。结果，经D-2P处理的器件（1.75 eV）实现了20.80%（认证为20.70%）的创纪录功率转换效率，这是WBG（大于1.74 eV）PSC报道的最高值。
