Song Xiaohui, Liu Zhen, Ma Zinan, Hu Yanjie, Lv Xiaojing, Li Xueping, Yan Yong, Jiang Yurong, Xia Congxin
Henan Key Laboratory of Photovoltaic Materials, School of Physics, Henan Normal University, Xinxiang 453007, China.
Department of Electronic and Electrical Engineering, Henan Normal University, Xinxiang 453007, China.
Nanophotonics. 2023 Aug 28;12(18):3671-3682. doi: 10.1515/nanoph-2023-0398. eCollection 2023 Sep.
The vertical electronic and optoelectronic devices based on 2D materials have shown great advantages over lateral devices, such as higher current density, faster switch speed, and superior short-channel control. However, it is difficult to fabricate vertical device with conventional metal deposition methods due to the aggressive process usually results in damage to the contact region. Here, we develop a simple and effective metal transfer technique and fabricate p-type and n-type WSe transistors by using metals with different work functions and subsequently create a vertical WSe transistors with a 18-nm-thick channel, which retain good gate coupling effect. Furthermore, a vertical WSe photodiode is constructed with graphene and Pt as asymmetric van der Waals (vdW) contacts. The work-function difference between graphene and Pt generates a built-in electric filed, leading to a high current rectification over 10. Under 405 nm laser illumination, the device exhibits excellent self-powered photodetection properties, including a high responsivity of 0.28 A W, fast response speed of 24 μs, and large light on/off ratio exceeding 10 at zero bias, which surpass most of the vdW photodiodes. This work demonstrates that the metal transfer technique is a promising strategy for the construction of high-performance vertical optoelectronic devices.
基于二维材料的垂直电子和光电器件相对于横向器件已展现出巨大优势，例如更高的电流密度、更快的开关速度以及卓越的短沟道控制能力。然而，采用传统金属沉积方法制造垂直器件存在困难，因为这种激进的工艺通常会导致接触区域受损。在此，我们开发了一种简单有效的金属转移技术，并通过使用具有不同功函数的金属制造了p型和n型WSe晶体管，随后创建了一个具有18纳米厚沟道的垂直WSe晶体管，该晶体管保留了良好的栅极耦合效应。此外，用石墨烯和铂作为非对称范德华（vdW）接触构建了一个垂直WSe光电二极管。石墨烯和铂之间的功函数差异产生了一个内建电场，导致高达10以上的高电流整流比。在405纳米激光照射下，该器件展现出优异的自供电光电探测特性，包括0.28安/瓦的高响应度、24微秒的快速响应速度以及在零偏压下超过10的大光开/关比，这超过了大多数vdW光电二极管。这项工作表明，金属转移技术是构建高性能垂直光电器件的一种有前景的策略。
