二维过渡金属硫属化物的界面和缺陷调控及光电性能研究

Interfaces and defects in two-dimensional (2D) transition metal dichalcogenides (TMDCs) have significant impact on optoelectronic properties. Interface engineering and defect engineering provide promising ways to modulate the properties of TMDCs in future electronics and optoelectronics and construct high-performance photodetectors. However, there has not been enough research on the influence of interface and defect on responsivity and response time of optoelectronic devices as well as the effective utilization of interface and defect to improve device performance, which restricts the rapid development and practical application of TMDCs. In this project, we will explore the mechanism of TMDCs/adsorbate interface to modulate the photoelectric properties of TMDCs with different layers and will also study the effects of different TMDCs/metal contact interfaces on TMDCs in combination with an e-beam-free transfer-electrode technique. Then, the influence of different types of defects on the photoresponsivity and the response time of TMDCs optoelectronic devices will be further revealed. Finally, we will explore the methods for designing the interface as well as ways of tuning types and concentration of defects. On this basis, suitable defects and interfaces engineering will be employed to improve the performance of optoelectronic devices, so as to achieve high-response and fast photoresponsivity simultaneously in TMDC-based photodetectors. The development of this project is helpful for us to understand the optoelectronic properties and master the modulating theory of two-dimensional materials like TMDCs, which is of great significance for promoting the development of optoelectronics.

界面和缺陷对二维过渡金属硫属化物（TMDCs）的光电性能具有很大的影响，也为制备高性能的光电探测器提供了可能的调控途径。然而，当前TMDCs中界面和缺陷对其光电器件的响应时间和响应率的影响机制的研究还不是很深入，基于界面和缺陷的调控也缺乏有针对性的有效手段，这在一定程度上限制了TMDCs在光电探测领域的快速发展和实用化。本项目拟研究不同的分子吸附界面和金属接触界面对TMDCs光电性能的作用机理；探究不同类型缺陷对TMDCs光电器件的光响应率和响应时间的影响机制。探索缺陷的类型与浓度的调控方法以及界面的设计方法；在此基础上，选择合适的缺陷和界面对TMDCs进行改性，从而获得兼具高响应率和快响应时间的光电探测器件。本项目的开展有助于理解和掌握以TMDCs为代表的二维材料的光电性质和调控理论，制备高性能的光电器件对促进光电子学的发展具有重要的意义。

当前过渡金属硫属化合物（TMDCs）中界面和缺陷对其光电器件的影响机制的研究不是很深入，基于界面和缺陷的调控也缺乏针对性的有效手段。本项目主要研究界面和缺陷调控TMDCs光电性能的机制，及TMDCs光电器件的优化设计。.研究界面对TMDCs光电性能的作用机理时发现：利用探针干法转移电极能够避免器件制备过程中界面的污染和缺陷的引入，构建多种二维器件；表面电荷转移掺杂随TMDCs层数增加，调控光电特性的机制由深缺陷能级转换成复合中心变成光诱导栅控效应，光电特性表现为从响应速度的加快变成响应率的提高。.探究不同类型缺陷对TMDCs光电器件的影响机制时发现：通过热处理和等离子体处理能在TMDCs中可控的引入不同类型和浓度的缺陷；热处理引入的氧缺陷能修复空位缺陷和降低接触电阻，增强响应率，而响应时间几乎不变；短时间等离子体处理引入空位缺陷，而长时间处理能引入用氧掺杂，实现对TMDC掺杂类型的控制。.探索利用界面和缺陷设计优化TMDCs光电性能的方案时发现：选择合适二维材料的层数，利用表面电荷转移掺杂能够构建二维PIN型光电二极管，实现光伏和光电导性能的显著提升；构建硫化铅量子点修饰的高灵敏和低功耗的TMDCs异质结二极管光电探测器，光伏下的响应时间在微秒级别，响应率最高达0.76 A/W。.本项目的研究工作为制备高性能和低功耗的二维半导体光电探测器提供思路，加快TMDCs在光电探测领域的发展和实用化。.在项目资助下，以通讯或第一作者共发表 SCI 论文 6 篇，其中高水平论文2篇（ACS Nano和Nano Research各一篇）。申请发明专利4项，其中授权1项。培养研究生8人，其中毕业1人。