大面积高质量WS2薄膜的可控生长及光电性能研究

Two-dimensional WS2 material has a wide application prospect in the field of optoelectronics because of its unique structure and excellent physical and chemical properties. However, there are many problems in the obtained two-dimensional WS2 materials, such as lattice defects, small yield and poor preparation reproducibility. This project proposes to synthesize some WS2 films by the self-assembly technique and the chemical vapor deposition method. We will in-depth study the relationship between the morphology and crystal orientation of nucleating agent WO3 particles and the morphology and quality of WS2 films through the theoretical analyses and in situ characterizations (such as Raman-AFM). So the nucleation and growth mechanism of WS2 films will be revealed, which is beneficial to realize the controllable growth of the large area high quality WS2 films. Then, we will fabricate the photodetectors based on the WS2 films and study the photoelectric properties of them by using the two-dimensional metal phase WTe2 as the connecting material. Through compared with the traditional metal connecting material, we will investigate the factors that influence the optoelectronic performances including WS2 film morphologies, crystal qualities, and interface between electrodes and materials, and research after the related mechanism between WS2 film microstructures, optoelectronic converting process and device performance. This project will provide a new idea and methode for the constructions of high-performance optoelectronic devices.

二维WS2材料由于其独特的结构和优异的物化性质在光电领域有着广泛的应用前景。但是，目前得到的WS2二维材料存在晶格缺陷多、产量小、制备可重复性差等问题。本项目拟采用单分子层自组装技术和化学气相沉积法结合制备WS2薄膜，通过理论分析和原位表征(Raman-AFM联用)等方法，深入研究成核剂WO3颗粒形貌、晶体取向和WS2薄膜形貌、晶体质量之间的关系，揭示其成核机理和生长机制，实现大面积高质量WS2薄膜的可控生长。继而，采用二维金属相WTe2作为连接材料，制备基于WS2薄膜的光电探测器并研究其光电性能。通过与传统金属连接材料进行对比，分析WS2薄膜形貌、晶体质量、电极与材料界面等对光电探测器件性能的影响规律，并探索WS2薄膜微观结构、光电转换过程与器件性能之间的关联机制，为构建高性能光电器件提供新思路和新方法。

二维过渡金属硫族化合物代表硫化钨(WS2) 由于其独特的结构和优异的物化性质引起了光电领域研究者的关注。但是，目前可重复性制备大面积高质量的WS2二维材料仍然比较困难，基于WS2的光电探测器性能也不理想，这些已经严重地制约了其应用。本项目采用单分子层自组装技术成功制备了WO3成核剂，然后结合化学气相沉积法生长WS2薄膜，通过理论分析和原位表征(Raman-AFM联用)等方法，深入研究了成核剂及生长条件与WS2薄膜形貌、晶体质量和层数的内在联系，探索WS2薄膜的成核和生长机制，实现了大面积高质量WS2薄膜的可控制备。项目还成功制备了二维金属相的碲化钨(WTe2)，并运用WTe2作为连接材料，制备了基于WS2薄膜的光电探测器，通过与传统金属连接材料探测器光电性能进行对比，探索了WS2薄膜微观结构、光电转换过程与器件性能之间的关联机制，为构建高性能光电器件提供新思路和新方法，有助于解决WS2甚至其它过渡金属硫族化合物的大规模工业化生产和应用难题。项目研究相关成果已发表SCI论文两篇，在投SCI论文两篇，已申请发明专利两项，其他结果仍在积极整理中。