Synthesis and Characterization of Metallic Janus MoSH Monolayer

Xi Wan; EnZi Chen; Jie Yao; Mingliang Gao; Xin Miao; Shuai Wang; Yanyun Gu; Shaoqing Xiao; Runze Zhan; Kun Chen; Zefeng Chen; Xiaoliang Zeng; Xiaofeng Gu; Jianbin Xu

doi:10.1021/acsnano.1c08531

Synthesis and Characterization of Metallic Janus MoSH Monolayer

ACS Nano. 2021 Dec 28;15(12):20319-20331. doi: 10.1021/acsnano.1c08531. Epub 2021 Dec 6.

Authors

Xi Wan¹, EnZi Chen², Jie Yao¹, Mingliang Gao¹, Xin Miao¹, Shuai Wang¹, Yanyun Gu¹, Shaoqing Xiao¹, Runze Zhan², Kun Chen², Zefeng Chen³, Xiaoliang Zeng⁴, Xiaofeng Gu¹, Jianbin Xu⁵

Affiliations

¹ Engineering Research Center of IoT Technology Applications (Ministry of Education), Department of Electronic Engineering, Jiangnan University, Wuxi 214122, China.
² State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology and Guangdong Province Key Laboratory of Display Material, Sun Yat-sen University, Guangzhou 510275, China.
³ School of Optoelectronic Science and Engineering, Soochow University, Suzhou 215006, China.
⁴ Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
⁵ Department of Electronic Engineering and Materials Science and Technology Research Center, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong Special Administrative Region 999077, People's Republic of China.

PMID: 34870978
DOI: 10.1021/acsnano.1c08531

Abstract

Janus transition-metal dichalcogenides (TMDCs) are emerging as special 2D materials with different chalcogen atoms covalently bonded on each side of the unit cell, resulting in interesting properties. To date, several synthetic strategies have been developed to realize Janus TMDCs, which first involves stripping the top-layer S of MoS₂ with H atoms. However, there has been little discussion on the intermediate Janus MoSH. It is critical to find the appropriate plasma treatment time to avoid sample damage. A thorough understanding of the formation and properties of MoSH is highly desirable. In this work, a controlled H₂-plasma treatment has been developed to gradually synthesize a Janus MoSH monolayer, which was confirmed by the TOF-SIMS analysis as well as the subsequent fabrication of MoSSe. The electronic properties of MoSH, including the high intrinsic carrier concentration (∼2 × 10¹³ cm^-2) and the Fermi level (∼ - 4.11 eV), have been systematically investigated by the combination of FET device study, KPFM, and DFT calculations. The results demonstrate a method for the creation of Janus MoSH and present the essential electronic parameters which have great significance for device applications. Furthermore, owing to the metallicity, 2D Janus MoSH might be a potential platform to observe the SPR behavior in the mid-infrared region.

Keywords: Janus; KPFM; MoS2; MoSH; MoSSe; plasma.