Zhang Shengnan, Li Ruijie, Yao Zhixin, Liao Peichi, Li Yifei, Tian Huifeng, Wang Jinhuan, Liu Peizhi, Guo Junjie, Liu Kaihui, Mei Fuhong, Liu Lei
Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, People's Republic of China. Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, People's Republic of China.
Nanotechnology. 2020 Jul 24;31(30):30LT02. doi: 10.1088/1361-6528/ab8766. Epub 2020 Apr 7.
The transition metal dichalcogenides (TMDCs) have been intensively investigated as promising nanoelectronic and optoelectronic materials. However, the pervasive adsorbates on the surfaces of monolayer TMDCs, including oxygen and water molecules from the ambient environment, tend to degrade the device performance, thus hindering specific applications. In this work, we report the effect of laser irradiation on the transport and photoresponse of monolayer MoS and WSe devices, and this laser annealing process is demonstrated as a straightforward approach to remove physically adsorbed contaminants. Compared to vacuum pumping and in situ thermal annealing treatments, the field-effect transistors after laser annealing show a more than one order of magnitude higher on-state current, and no apparent degradation of device performance at low temperatures. The mobility of the monolayer WSe devices can be enhanced by three to four times, and for single-layered MoS devices with the commonly used SiO as the back-gate, the mobility increases by 20 times, reaching [Formula: see text]. The efficient cleaning effect of laser annealing is also supported by the reduction of channel and contact resistance revealed by a transmission line experiment. Further, an enhanced photocurrent, by a factor of ten, has been obtained in the laser annealed device. These findings pave the way for high-performance monolayer TMDC-based electronic and optoelectronic devices with a clean surface and intrinsic properties.
过渡金属二硫属化物（TMDCs）作为有前景的纳米电子和光电子材料已被深入研究。然而，单层TMDCs表面普遍存在的吸附物，包括来自周围环境的氧和水分子，往往会降低器件性能，从而阻碍特定应用。在这项工作中，我们报告了激光辐照对单层MoS和WSe器件的输运和光响应的影响，并且这种激光退火过程被证明是一种去除物理吸附污染物的直接方法。与真空泵抽气和原位热退火处理相比，激光退火后的场效应晶体管的导通态电流高出一个多数量级，并且在低温下器件性能没有明显退化。单层WSe器件的迁移率可以提高三到四倍，对于以常用的SiO作为背栅的单层MoS器件，迁移率增加20倍，达到[公式：见原文]。传输线实验揭示的沟道和接触电阻的降低也支持了激光退火的有效清洁效果。此外，在激光退火器件中获得了增强十倍的光电流。这些发现为具有清洁表面和本征特性的高性能单层TMDC基电子和光电子器件铺平了道路。
