Zhao Wen-Hui, Liang Zheng, Liu Yao-Zhong, Deng Zi-Qiang, Ouyang Yu-Lou, Tan Rui, Yao Yong-Sheng, Wei Xiao-Lin, Tang Zhen-Kun
College of Physics and Electronics Engineering, Hengyang Normal University, Hengyang 421002, China.
Dalton Trans. 2023 Aug 15;52(32):11067-11075. doi: 10.1039/d3dt01807e.
Two-dimensional Ruddlesden-Popper (2D RP) perovskites can form layered protective materials using long organic cations as "barrier" caps, which is expected to solve the problem of instability of perovskites in the working environment. In this work, we systematically studied the 2D Ruddlesden-Popper (CHCHNH)PbI hybrid perovskites using density functional theory. The results reveal that the 2D (CHCHNH)PbI perovskites are semiconductors with band gaps of 2.22 eV. The optical absorption peak of the 2D (CHCHNH)PbI perovskite structure is located at 532 nm in the visible region. Interestingly, the optical absorption spectrum of the 2D (CHCHNH)PbI perovskite structure enhanced under suitable strains. The highest optical absorption peak appears in 2D (CHCHNH)PbI under a -2% strain, and its theoretical photoelectric conversion efficiency is 28.5%. More interestingly, the replacement of surface I atoms with Br is another ways to enhance the optical absorption spectrum of the 2D (CHCHNH)PbI perovskite structure. The optical absorption peak blue-shifts to the high energy region, which has higher solar energy flux density than the low energy region. The good stability, tuneable band gap and excellent theoretical photoelectric conversion efficiency of the 2D (CHCHNH)PbI perovskite structure make it a promising candidate for novel 2D hybrid perovskite based photoelectronic devices and solar cells.
二维Ruddlesden-Popper（2D RP）钙钛矿可以使用长有机阳离子作为“阻挡”帽来形成层状保护材料，这有望解决钙钛矿在工作环境中的不稳定性问题。在这项工作中，我们使用密度泛函理论系统地研究了二维Ruddlesden-Popper（CHCHNH）PbI混合钙钛矿。结果表明，二维（CHCHNH）PbI钙钛矿是带隙为2.22 eV的半导体。二维（CHCHNH）PbI钙钛矿结构的光吸收峰位于可见光区域的532 nm处。有趣的是，二维（CHCHNH）PbI钙钛矿结构的光吸收光谱在适当应变下增强。在-2%应变下，二维（CHCHNH）PbI中出现最高光吸收峰，其理论光电转换效率为28.5%。更有趣的是，用Br取代表面I原子是增强二维（CHCHNH）PbI钙钛矿结构光吸收光谱的另一种方法。光吸收峰蓝移到高能区域，该区域比低能区域具有更高的太阳能通量密度。二维（CHCHNH）PbI钙钛矿结构良好的稳定性、可调节的带隙和优异的理论光电转换效率使其成为基于新型二维混合钙钛矿的光电器件和太阳能电池的有前途的候选材料。
