二维过渡金属硫属化合物的可控生长和温度调制的发光动力学研究

二维过渡金属硫属化合物（2D TMDCs）具有厚度依赖的能带结构、较大的载流子迁移率、强自旋轨道耦合作用和高激子结合能等特点，逐渐成长为先进微纳光电器件研究领域中一类重要的材料体系。然而，目前基于2D TMDCs体系的材料和器件仍呈现出较低的量子效率水平，无法满足实际应用需求。鉴于此，本项目拟开展常见2D TMDCs的可控生长和温度依赖载流子动力学研究。借助“多次生长法”制备层数可控的高质量连续2D TMDCs薄膜；利用稳态/瞬态变温光谱技术，探究2D TMDCs的发光动力学，揭示参与辐射/非辐射复合过程的载流子跃迁机制，阐明2D TMDCs体系量子效率低的根本原因；调控2D TMDCs中的载流子行为，减少非辐射复合路径，增加高荧光效率复合通道，实现显著提升2D TMDCs荧光强度的基本目标。本项目探究了2D TMDCs的可控生长策略和温度调制的发光动力学机制，是凝聚态物理学的前沿课题。

Two-dimensional transition metal dichalcogenides (2D TMDCs) have gradually become an important candidate for advanced optoelectronic device application, owing to their fantastic properties such as thickness-dependent energy band structure, relatively large carrier mobility, strong spin-orbital coupling interaction and high exciton binding energy. However, materials and devices based on these 2D TMDCs still show a very low quantum efficiency currently, and cannot meet the practical application requirements. In view of this point, this project intends to study the controllable growth and temperature-dependent carrier dynamics of commonly-seen 2D TMDCs. By virtue of a “multiple-growth-method”, high-quality and continuous 2D TMDCs film with controllable layer thickness can be well prepared. The luminescence dynamics of 2D TMDCs could be clearly resolved via temperature-dependent steady-state/transit-state spectroscopy study, which can uncover the transition mechanisms of photo-carriers participating in radiative/non-radiative recombination process and reveal the intrinsic cause of low quantum efficiency in 2D TMDCs. Furthermore, by modulating the behavior of excited-state carriers in 2D TMDCs, non-radiative recombination paths could be effectively reduced, whereas radiative recombination channels with high fluorescence efficiency shall be remarkably increased. Based on the above strategies, the whole fluorescence intensity of 2D TMDCs system could be efficiently improved. This project aims to explore the controllable growth strategy and temperature- modulated luminescence dynamics of 2D TMDCs, which is a cutting-edge research proposal in the field of condensed matter physics.