Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune 411008, India.
Department of Physics, Indian Institute of Science Education and Research (IISER), Pune 411008, India.
J Phys Chem Lett. 2023 Feb 23;14(7):1870-1876. doi: 10.1021/acs.jpclett.2c03861. Epub 2023 Feb 13.
Hybrid lead halide perovskites and their derivatives are important optoelectronic materials but suffer from water instability. Combining both the optoelectronics and the water stability of such systems is a major challenge in material design today. To address this issue, we employ the well-known π-conjugation and cation-π interaction concepts in designing a hybrid lead halide perovskite derivative system. (4,4'-VDP)PbBr (VDP = vinylenedipyridinium) single crystals are prepared. They have a one-dimensional (1D) arrangement of inorganic Pb-Br sublattices connected via the 4,4'-VDP organic sublattice. The π-conjugation in the 4,4'-VDP sublattice allows electronic communication between the 1D Pb-Br units, reducing the band gap and improving the photoconductivity. Importantly, N of one 4,4'-VDP molecular ion interacts with the π-electron cloud of the adjacent one. This intermolecular cation-π interaction extends throughout the organic sublattice, making the hybrid crystal stable when stored under water for more than a year without requiring any encapsulations.
杂化卤化铅钙钛矿及其衍生物是重要的光电材料，但它们对水不稳定。将此类系统的光电性能和水稳定性结合起来是当今材料设计的主要挑战。为了解决这个问题，我们在设计杂化卤化铅钙钛矿衍生物系统时采用了众所周知的π共轭和阳离子-π相互作用的概念。（4,4'-VDP）PbBr（VDP = 乙烯二吡啶）单晶被制备出来。它们具有通过 4,4'-VDP 有机亚晶格连接的一维（1D）无机 Pb-Br 亚晶格排列。4,4'-VDP 亚晶格中的π共轭允许一维 Pb-Br 单元之间的电子通信，从而降低了能带隙并提高了光电导率。重要的是，一个 4,4'-VDP 分子离子的 N 与相邻分子的π电子云相互作用。这种分子间阳离子-π相互作用贯穿整个有机亚晶格，使得混合晶体在水中储存超过一年而无需任何封装时仍然稳定。
