三元硫属化合物二维超薄结构的制备、电子结构调控及光电性能研究

Ultrathin two-dimensional (2D) structure is crucial materials for the design of new-generation of portable nanodevices. In the current project, we will design universal synthetic routes for the controllable synthesis of the 2D crystal of ternary chalcogenides as well as the optimization and modulation of their photoelectric properties. With the synergic combination of X-ray absorption fine structure (XAFS) analysis and density functional theoretical (DFT) calculations, the effect of ultrathin thickness and surface lattice distortion of 2D crystal on its electronic structure will be studied. In addition, the law of electronic modulation of 2D crystals by surface functionalization, electric charge doping and so forth will also be studied. Those results will be helpful for the study of the relationship between electronic structural and photoelectrical properties of 2D crystals. Through the assembly of the free-standing 2D crystals with ultrathin thickness into integrated films with transferable properties, the 2D crystal film based photoelectric devices with fast response speed, high sensitivity and high on-off ratio will be designed. The results of this proposed research will provide not only theoretical and methodological guidelines for the developments of the area of 2D crystals, but also materials for the design of high-quality photoelectric devices.

二维超薄结构是构筑新一代便携式纳米器件的关键材料。本项目拟以具有独特光电性能的新型三元硫属化合物二维超薄结构为主要研究对象，设计基于材料结构特点的普适性合成方法，实现新型三元硫属化合物二维超薄结构的宏量可控制备及其光电性能的优化调控。基于同步辐射精细X射线吸收谱图解析和密度泛函理论计算结合，探索超薄晶体厚度、表面晶格扭曲对二维超薄结构的电子结构的影响机制，以及表面功能化、电荷掺杂等手段对其电子结构的调控规律，从而建立三元硫属化合物二维超薄结构的电子结构与光电性能之间的关系。通过对所获得二维超薄结构进行可控宏观二维组装和转移，实现具有较快响应速度、较高灵敏度和高开关比基于二维超薄结构薄膜的光电器件的构筑。预期成果将为二维超薄结构新领域的发展提供理论和方法指导，为制备高质量光电元器件提供关键材料。

二维超薄结构是指具有单个原子层或几个原子层厚度的二维纳米材料，近年来以其独特的电子结构特征二维超薄材料吸引了广泛的研究。在本项目实施过程中，项目负责人基于过渡金属硫属化合物二维超薄结构开展了系统的研究，同时拓展了其它体系二维材料的研究，取得了系列成果。实现了二维超薄结构的宏量制备；提出了通过掺杂、空位、表面功能化等方法来调控二维超薄结构的电子结构；进而优化了二维超薄结构在光、电响应方面的性能。该项目展现了二维超薄结构在能源相关领域的应用前景。基于以上研究，负责人在J. Am. Chem. Soc. (3篇), Angew. Chem. Int. Ed. (4篇), Adv. Mater. (2篇)等化学、材料重要期刊发表论文16篇，应邀为Nano Today，《无机化学学报》撰写综述论文。