UV illumination enhanced desorption of oxygen molecules from monolayer MoS2 surface  

作　　者：Yuhang Wang Zhiquan He Jinbing Zhang Hao Liu Xubo Lai Boyang Liu Yibao Chen Fengping Wang Liuwan Zhang 

机构地区：[1]Department of Applied Plhysics,School ofMathematics and Physics,University of Science and Techmology Bejing,Beijing 10083,China [2]State Key Laboratory of Low-Dimensional Quantum Physics,Collaborative Innovation Center of Quantum Matter,Department of Physics,Tsinghua University,Beijing 100084,China

出　　处：《Nano Research》2020年第2期358-365,共8页纳米研究（英文版）

基　　金：This work is supported by the National Natural Science Foundation of China(Nos.11074142 and 11021464);Collaborative Innovation Center of Weak Signal-Detecting Materials and Devices Integration of Anhui University(No.01001795-201601);Fundam ental Research Funds for the Central Universities(No.FRP-TP-18-076A1);the China Postdoctoral Science Foundation(No.2017M610857).

摘　　要：The oxygen adsorption can drastically alter the electronic properties of the two-dimensional(2D)materials,which is usually dificult to be removed.In this work,we report the ultraviolet(UV)ilumination induced desorption of the O2 molecules from the monolayer MoS2 surface by using the atmosphere dependent transport measurement,Kelvin probe microscopy,photoluminescence spectroscopy and X-ray photoelectron spectroscopy.Obvious increasing of the conductivity,rising of the Fermi level,and red shift of the photoluminescence peaks of the MoS2 were observed after the UV ilumination in vacuum,indicating the elimination of the depletion effect from the oxygen adsorption.Such parameter changes can be reversibly recovered by the subsequent O2 exposure.Furthermore,obvious decreasing of the oxygen concentration after the UV ilumination was also observed by X-ray photoelectron spectroscopy.Thus the UV induced O2 photodesorption effect is evidenced.The photo-excited charge transfer mechanism is proposed to account for the photodesorption effect.These results provide a nondestructive way to clean the MoS2 surface and manipulate the performance of the MoS2 based devices.

关 键 词：MOS2 DESORPTION ultraviolet(UV)ilumination oxygen adsorption carrier density 

分 类 号：O64[理学—物理化学]