Back to Search Start Over

Monolayer Bismuthene-Metal Contacts: A Theoretical Study

Authors :
Guo, Ying
Pan, Feng
Ye, Meng
Sun, Xiaotian
Wang, Yangyang
Li, Jingzhen
Zhang, Xiuying
Zhang, Han
Pan, Yuanyuan
Song, Zhigang
Yang, Jinbo
Lu, Jing
Source :
ACS Applied Materials & Interfaces; June 2017, Vol. 9 Issue: 27 p23128-23140, 13p
Publication Year :
2017

Abstract

Bismuthene, a bismuth analogue of graphene, has a moderate band gap, has a high carrier mobility, has a topological nontriviality, has a high stability at room temperature, has an easy transferability, and is very attractive for electronics, optronics, and spintronics. The electrical contact plays a critical role in an actual device. The interfacial properties of monolayer (ML) bismuthene in contact with the metal electrodes spanning a wide work function range in a field-effect transistor configuration are systematically studied for the first time by using both first-principles electronic structure calculations and quantum transport simulations. The ML bismuthene always undergoes metallization upon contact with the six metal electrodes owing to a strong interaction. According to the quantum transport simulations, apparent metal-induced gap states (MIGSs) formed in the semiconductor–metal interface give rise to a strong Fermi-level pinning. As a result, the ML bismuthene forms an n-type Schottky contact with Ir/Ag/Ti electrodes with electron Schottky barrier heights (SBHs) of 0.17, 0.22, and 0.25 eV, respectively, and a p-type Schottky contact with Pt/Al/Au electrodes with hole SBHs of 0.09, 0.16, and 0.38 eV, respectively. The effective channel length of the ML bismuthene transistors is also significantly reduced by the MIGSs. However, the MIGSs are eliminated and the effective channel length is increased when ML graphene is used as an electrode, accompanied by a small hole SBH of 0.06 eV (quasi-Ohmic contact). Hence, an insight is provided into the interfacial properties of the ML bismuthene–metal composite systems and a guidance is provided for the choice of metal electrodes in ML bismuthene devices.

Details

Language :
English
ISSN :
19448244
Volume :
9
Issue :
27
Database :
Supplemental Index
Journal :
ACS Applied Materials & Interfaces
Publication Type :
Periodical
Accession number :
ejs42358633
Full Text :
https://doi.org/10.1021/acsami.7b03833