Quasi-freestanding, striped WS2 monolayer with an invariable band gap on Au（001）  

作　　者：Min Hong Xiebo Zhou Jianping Shi Yue Qi Zhepeng Zhang Qiyi Fang Yaguang Guo Yajuan Sun Zhongfan Liu Yuanchang Li Qian Wang Yanfeng Zhang 

机构地区：[1] Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China [2] Center for Nanochemistry(CNC), Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China [3] State Key Laboratory of Coal-based Low-carbon Energy, ENN Group Co., Ltd., Langfang 065001, China [4] National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing 100190, China [5]Center for Applied Physics and Technology, Peking University, Beijing 100871, China

出　　处：《Nano Research》2017年第11期3875-3884,共10页纳米研究（英文版）

基　　金：We acknowledge financial support by the National Natural Science Foundation of China （Nos. 51472008 and 51290272）, the National Key Research and Development Program of China （No. 2016YFA0200103）,the Beijing Municipal Science and Technology Planning Project （No. Z151100003315013）, the Open Research Fund Program of the State Key Laboratory of Low- Dimensional Quantum Physics （No. KF201601） and the ENN Energy Research Institute.

摘　　要：Revealing the structural/electronic features and interfacial interactions of monolayer MoS2 and WS2 on metals is essential to evaluating the performance of related devices.In this study,we focused on the atomic-scale features of monolayer WS2 on Au（001） synthesized via chemical vapor deposition.Scanning tunneling microscopy and spectroscopy reveal that the WS2/Au（001） system exhibits a striped superstructure similar to that of MoS2/Au（001） but weaker interfacial interactions,as evidenced by experimental and theoretical investigations.Specifically,the WS2/Au（001） band gap exhibits a relatively intrinsic value of ～ 2.0 eV.However,the band gap can gradually decrease to ～ 1.5 eV when the sample annealing temperature increases from ～370 to 720 ℃.In addition,the doping level （or Fermi energy） of monolayer WS2/Au（001） varies little over the valley and ridge regions of the striped patterns because of the homogenous distributions of point defects introduced by annealing.Briefly,this work provides an in-depth investigation into the interfacial interactions and electronic properties of monolayer MX2 on metal substrates.Revealing the structural/electronic features and interfacial interactions of monolayer MoS2 and WS2 on metals is essential to evaluating the performance of related devices.In this study,we focused on the atomic-scale features of monolayer WS2 on Au（001） synthesized via chemical vapor deposition.Scanning tunneling microscopy and spectroscopy reveal that the WS2/Au（001） system exhibits a striped superstructure similar to that of MoS2/Au（001） but weaker interfacial interactions,as evidenced by experimental and theoretical investigations.Specifically,the WS2/Au（001） band gap exhibits a relatively intrinsic value of ～ 2.0 eV.However,the band gap can gradually decrease to ～ 1.5 eV when the sample annealing temperature increases from ～370 to 720 ℃.In addition,the doping level （or Fermi energy） of monolayer WS2/Au（001） varies little over the valley and ridge regions of the striped patterns because of the homogenous distributions of point defects introduced by annealing.Briefly,this work provides an in-depth investigation into the interfacial interactions and electronic properties of monolayer MX2 on metal substrates.

关 键 词：WS2 Au（001） striped superstructure interfacial interaction STM/STS 

分 类 号：O[理学]