基于层状过渡金属硫化物的三维共形异质结光电探测器研究

The layered transition metal dichalcogenide has the advantages of high mobility and high absorptivity, and is expected to realize the application of high performance photodetectors. However, due to the limitation of intrinsic optical bandgap, the weak absorption of planar few-layer structure and the lack of highquality junctions, the current transition metal dichalcogenide-based detectors do not have excellent broadband, especially infrared, photoresponse. Moreover, the challenge of large-area and low-cost preparation also greatly limits its commercial applications. In response to the above key scientific issues, the project intends to focus on the following three aspects: (1) preparation of large-area transition metal dichalcogenide films through chemical thermal decomposition method; (2) changing the categories and concentrations of defects in transition metal dichalcogenides to adjust the optical bandgap; (3) preparation of the silicon micro/nano structure arrays, and realizing the conformal coating or growth of the transition metal dichalcogenides on the surface, constructing the transition metal dichalcogenide/structured silicon conformal heterojunctions for high-performance photodetectors. The above research provides a theoretical and experimental basis for the development of low-cost, broadband response, and high-performance transition metal dichalcogenide photodetectors.

层状过渡金属硫化物具有高迁移率、高吸收率等优点，有望实现高性能光电探测器的应用。然而，由于本征光学带隙限制、平面薄膜结构光吸收弱以及缺少高质量异质结等因素，当前基于过渡金属硫化物的探测器不具备理想的宽波段尤其红外波段响应的能力。而且，大面积、低成本制备的难题也极大限制了其商业化应用。针对上述关键科学问题，本项目拟重点开展以下三个方面的工作：（1）采用化学热分解法进行大面积过渡金属硫化物薄膜的制备；（2）改变过渡金属硫化物中晶格缺陷的类型和浓度，实现其光学带隙的可调，从而拓宽光吸收波段；（3）实现过渡金属硫化物在硅结构表面的共形包覆或生长，构筑基于过渡金属硫化物/结构硅共形异质结的高性能光电探测器。以上研究为发展低成本、宽光谱、高性能的过渡金属硫化物光电探测器提供理论和实验基础。

以过渡金属硫化物、石墨烯为代表的二维材料具有优异的光学、电学性质，是发展高性能光电、储能等功能器件的理想材料。本项目研究了二硫化钨等过渡金属硫化物的大面积薄膜制备技术，发现了通过调控原子序数比实现其光学带隙的可调，构建了基于过渡金属硫化物/结构硅的宽光谱探测器；开发了基于有机物/硅异质结的光伏电池，得益于石墨烯的透明导电性和设计的双层减反层，电池具备了高转换效率和稳定性，并通过在硅表面刻蚀不同尺寸的倒金字塔阵列，使电池同时呈现高分辨率、高对比度的定制化图案；利用石墨烯材料易功能复合优势，分别合成了四氧化三铁@石墨烯和二氧化锰@石墨烯量子点复合电极，组装的超级电容器兼顾高功率密度、高能量密度和超长循环寿命；通过一系列实体过充试验，掌握了锂离子电池热失控诱导及演化机制，提出了基于氢气特征气体的预警策略，发展了分子探针电池热失控预警技术，大幅提升储能安全预警时效性。本项目共发表SCI论文8篇、EI论文1篇、中文核心论文3篇，授权中国发明专利8件，制定发布地方、团体等技术标准3项。