1. Controlling the Schottky barrier at MoS2/metal contacts by inserting a BN monolayer.
- Author
-
Farmanbar, Mojtaba and Brocks, Geert
- Subjects
- *
SCHOTTKY barrier , *SEMICONDUCTOR-metal boundaries , *DENSITY functional theory , *FERMI level , *ELECTRONIC structure , *CONDUCTION bands - Abstract
Making a metal contact to the two-dimensional semiconductor MoS2 without creating a Schottky barrier is a challenge. Using density functional calculations we show that, although the Schottky barrier for electrons obeys the Schottky-Mott rule for high work function (≳ 4.7 eV) metals, the Fermi level is pinned at 0.1-0.3 eV below the conduction band edge of MoS2 for low work function metals, due to the metal-MoS2 interaction. Inserting a boron nitride (BN) monolayer between the metal and the MoS2 disrupts this interaction, and restores the MoS2 electronic structure. Moreover, a BN layer decreases the metal work function of Co and Ni by ~2 eV, and enables a lineup of the Fermi level with the MoS2 conduction band. Surface modification by adsorbing a single BN layer is a practical method to attain vanishing Schottky barrier heights. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF