Wang Zhen, Xia Hui, Wang Peng, Zhou Xiaohao, Liu Chunsen, Zhang Qinghua, Wang Fang, Huang Menglin, Chen Shiyou, Wu Peisong, Chen Yunfeng, Ye Jiafu, Huang Shenyang, Yan Hugen, Gu Lin, Miao Jinshui, Li Tianxin, Chen Xiaoshuang, Lu Wei, Zhou Peng, Hu Weida
State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China.
School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China.
Adv Mater. 2021 Dec;33(48):e2104942. doi: 10.1002/adma.202104942. Epub 2021 Sep 27.
For each generation of semiconductors, the issue of doping techniques is always placed at the top of the priority list since it determines whether a material can be used in the electronic and optoelectronic industry or not. When it comes to 2D materials, significant challenges have been found in controllably doping 2D semiconductors into p- or n-type, let alone developing a continuous control of this process. Here, a unique self-modulated doping characteristic in 2D layered materials such as PtSSe, PtS Se , PdSe , and WSe is reported. The varying number of vertically stacked-monolayers is the critical factor for controllably tuning the same material from p-type to intrinsic, and to n-type doping. Importantly, it is found that the thickness-induced lattice deformation makes defects in PtSSe transit from Pt vacancies to anion vacancies based on dynamic and thermodynamic analyses, which leads to p- and n-type conductance, respectively. By thickness-modulated doping, WSe diode exhibits a high rectification ratio of 4400 and a large open-circuit voltage of 0.38 V. Meanwhile, the PtSSe detector overcomes the shortcoming of large dark-current in narrow-bandgap optoelectronic devices. All these findings provide a brand-new perspective for fundamental scientific studies and applications.
对于每一代半导体而言，掺杂技术问题始终被置于优先事项的首位，因为它决定了一种材料能否应用于电子和光电子行业。对于二维材料，在将二维半导体可控地掺杂成p型或n型方面已发现重大挑战，更不用说对这一过程进行连续控制了。在此，报道了二维层状材料（如PtSSe、PtS₂Se、PdSe₂和WSe₂）中一种独特的自调制掺杂特性。垂直堆叠单分子层数量的变化是将同一材料从p型可控调节为本征型，进而调节为n型掺杂的关键因素。重要的是，基于动力学和热力学分析发现，厚度诱导的晶格变形使PtSSe中的缺陷从Pt空位转变为阴离子空位，这分别导致了p型和n型电导。通过厚度调制掺杂，WSe₂二极管表现出4400的高整流比和0.38 V的大开路电压。同时，PtSSe探测器克服了窄带隙光电器件中暗电流大的缺点。所有这些发现为基础科学研究和应用提供了全新的视角。
