二维WS2/Si异质结的制备及光电性能研究

Two dimensional (2D) materials have attracted much attention in the areas of condensed matter physics, nanomaterials, and optoelectronics due to their unique physical and chemical properties. 2D semiconducting transition metal dichalcogenide layered materials have proper bandgap and show high performance in the area of photodetection area. Recently, the heterostructures based on 2D material and Si have attracted much attention and show attracting potential application in photodetection area. The aim of the project is to investigate the optoelectronic characteristics of the WS2/Si heterostructure, which is fabricated by direct growth of WS2 on Si substrate. We will study the effects of the growth mode of WS2, the conductive type and doping concentration of Si, the area of the heterostructure, and the introduction of metal nanoparticles and semiconductor quantum dots on the photodetection performance of the heterostructures, such as photo-response spectrum, photo-responsivity, and photo-response speed, explore the method to enhance the photodection performance of the heterostructure. Our study will be helpful to enhance the recognition of the photodection performance of 2D/Si heterostructure, and provide advices for the application of 2D materials in Si-based optoelectronic integrated circuits.

二维材料具有独特的物理、化学性质，成为了凝聚态物理、纳米材料、光电子等领域的研究热点。二维过渡金属硫族半导体具有合适的能带宽度，在光电探测领域显示出优异的性能。近期，基于二维材料同硅基构成异质结受到了研究人员的关注和重视，并在光电探测领域显示出诱人的应用前景。本项目拟研究将WS2直接生长于Si上所构成的异质结的光电特性，研究不同生长模式WS2、Si的导电类型和掺杂浓度、结区面积以及引入金属纳米颗粒、半导体量子点对器件的光响应谱、光响应度和响应时间等的影响规律和物理机制，探索提高器件性能的方法。本研究将有助于加深对二维材料/硅异质结光电性能的认识，为二维材料在硅基光电集成电路中的应用提供指导。

二维材料及基的异质结显示出优异的光电性质，在光电子领域具有光明的应用前景。本项目开展了二维材料和二维材料异质结的可控制备、电子学和光电子学性质方面的研究工作，取得了一系列创新性的成果。主要成果为采用化学气相沉积方法成功制备了晶圆尺度的单层硫化钨薄膜，并且晶畴大小可调节，单畴硫化钨薄膜具有优异的光电性能；在氢氧化钠辅助下，利用化学沉积方法成功合成了单畴尺度达550 μm的单层硫化钨薄膜，并且其光电性能可同机械剥离的单层硫化钨相比拟；利用单层硫化钨晶界处的悬挂键实现了硫化镉纳米颗粒链的生长，从而使得单层硫化钨薄膜的晶畴在光学显微镜和扫描电子显微镜下直接成像，此外硫化镉的引入增强了硫化钨薄膜的光电响应特性；采用化学气相沉积方法成功地合成了石墨烯/硫化钨范德瓦尔斯外延异质结，该异质结显示出出色的光电探测性能；利用化学气相沉积实现了二维碘化铅纳米片阵列的合成，并且成功将碘化铅转化为卤素钙钛矿纳米片，二维碘化铅纳米片和卤素钙钛矿纳米片均显示出优异的光电探测性能；通过光刻工艺构建了硅/硫化钨/石墨烯范德瓦尔斯异质结光电探测器，探测器显示出优良的光电探测性能。相关研究成果为二维材料及其异质结在光电子领域的应用提供了科学参考和实验支持。