水稳定的联吡啶基有机金属卤化物晶体生长及性能机理研究

有机金属卤化物材料在光电领域展现出巨大的应用前景，但是其遇水极易分解。引入长链胺形成的层间范德华力或氢键能够有效改善稳定性，但是无法保持材料结构的长期水稳定性。调控有机阳离子与金属离子的配位作用，是提高材料本征水稳定性的有效途径。基于联吡啶（Bpy）具有的大离子半径且易与金属配位等特点，本项目拟通过调控联吡啶与金属离子的配位作用及晶体组分来生长新型水稳定且带隙可调的联吡啶基金属卤化物晶体，并系统研究水处理前后晶体本征性质的变化规律，结合其光电应用的长期性能评价水稳定性，进一步利用密度泛函理论揭示联吡啶与金属离子的作用关系及晶体表面与水分子的作用关系，理论结合实验阐明水稳定性机理。通过调控配位作用成功制备的4,4BpyPbI2和4,4BpyPbI4晶体及其优异的水稳定性和光电性能，表明本项目的可行性。该项目的开展有助于深入理解有机金属卤化物材料的水稳定性，推动该类材料与器件的进一步发展。

Organometallic halide materials have exhibited great applications in photoelectric field. However, it is easy to decompose when exposed to water. The van der Waals or hydrogen bonding interactions can efficient improve the stability formed from the long chain amine cations. However, this cannot strong enough for the long time water stability. Controlling the coordination between organic cations and metal cations is an effective strategy to improve the intrinsic water stability of halide materials. Based on the large size of bipyridine cations and its easy coordination with metal cations, in this project, the novel water stable organometallic halide crystals with tunable bandgap will be designed and grown by regulating and the coordination between the bipyridine cations and metal cations as well as the crystal composition. The intrinsic properties before and after the water treatment will be studied systematically, and the water stability will be further evaluated by the long-term performance of photoelectric application. The interaction between bipyridine and metal cations as well as the interaction between crystal surface and the water molecules will be investigated according to density functional theory in order to elucidate the water stable mechanism. The current study of this project will contribute to the deep understanding of the water stability for the organometallic halide materials and promotes the further development of this kind of materials and devices.