Zhang Cong-Cong, Yuan Shuai, Lou Yan-Hui, Liu Qing-Wei, Li Meng, Okada Hiroyuki, Wang Zhao-Kui
Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou, 215123, China.
Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555, Japan.
Adv Mater. 2020 Sep;32(38):e2001479. doi: 10.1002/adma.202001479. Epub 2020 Aug 9.
Interface strains and lattice distortion are inevitable issues during perovskite crystallization. Silane as a coupling agent is a popular connector to enhance the compatibility between inorganic and organic materials in semiconductor devices. Herein, a protonated amine silane coupling agent (PASCA-Br) interlayer between TiO and perovskite layers is adopted to directionally grasp both of them by forming the structural component of a lattice unit. The pillowy alkyl ammonium bromide terminals at the upper side of the interlayer provide well-matched growth sites for the perovskite, leading to mitigated interface strain and ensuing lattice distortion; meanwhile, its superior chemical compatibility presents an ideal effect on healing the under-coordinated Pb atoms and halogen vacancies of bare perovskite crystals. The PASCA-Br interlayer also serves as a mechanical buffer layer, inducing less cracked perovskite film when bending. The developed molecular-level flexible interlayer provides a promising interfacial engineering for perovskite solar cells and their flexible application.
在钙钛矿结晶过程中，界面应变和晶格畸变是不可避免的问题。硅烷作为一种偶联剂，是增强半导体器件中无机和有机材料之间兼容性的常用连接剂。在此，在TiO和钙钛矿层之间采用质子化胺硅烷偶联剂（PASCA-Br）中间层，通过形成晶格单元的结构组分来定向捕获它们。中间层上侧的枕状烷基溴化铵末端为钙钛矿提供了匹配良好的生长位点，从而减轻了界面应变并减少了随之而来的晶格畸变；同时，其优异的化学兼容性对修复裸钙钛矿晶体中配位不足的Pb原子和卤素空位具有理想效果。PASCA-Br中间层还可作为机械缓冲层，在弯曲时使钙钛矿薄膜产生较少裂纹。所开发的分子级柔性中间层为钙钛矿太阳能电池及其柔性应用提供了一种有前景的界面工程。
