Effects of Se substitution on the Schottky barrier of a MoSxSe(2−x)/graphene heterostructure. (23rd April 2021)

• Record Type: Journal Article
• Authors: Yin, Kui; Huang, Tao; Wu, Hong-Yu; Si, Yuan; Lian, Ji-Chun; Xiao, Yu-Wen; Zhang, Zhaogang; Huang, Wei-Qing; Hu, Wangyu; Huang, Guo-Fang
• Is Part Of: Journal of physics. Volume 54:Number 26(2021)
• Publication Date: 2021-04-23
• Subjects: Schottky barrier -- heteroatom substitution -- field-effect transistors -- van der Waals heterostructures -- MoSxSe(2−x)/graphene; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/abf44d
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: One of the most fundamental and challenging tasks to achieve high-performance ultra-thin atomic field effect transistors (FETs) is to obtain very low or even zero Schottky barrier height (SBH) at source/drain contact. Here, we propose that heteroatom substitution is an effective strategy to tune the performance of two-dimensional materials-based FETs, which is demonstrated by systematically exploring the effects of Se substitution on the structural and electronic properties, and SBH of MoS x Se(2− x ) /graphene (MoS x Se(2− x ) /G) heterostructures using first-principles calculations. Our findings suggest that the type and height of Schottky barrier can be adjusted by varying Se concentration. The transformation from n-type Schottky barrier to p-type Schottky barrier can be realized when the Se concentration is greater than 25%. With the increase of Se concentration, a lower p-type Schottky barrier can be obtained at the interface to achieve efficient charge transfer. Moreover, the Schottky barrier of MoS x Se(2− x ) /G heterostructures with different Se concentration would disappear as the external electric field exceeds certain values. These results would provide a direction in developing high-performance FETs involving heteroatom substitution layers as contact electrodes.