First-principles analysis of MoS2/Ti2C and MoS2/Ti2CY2 (Y=F and OH) all-2D semiconductor/metal contacts

Gan, Liyong; Huang, Dan; Schwingenschlögl, Udo; Zhao, Yu-Jun

First-principles analysis of MoS2/Ti2C and MoS2/Ti2CY2 (Y=F and OH) all-2D semiconductor/metal contacts

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First-principles analysis of MoS2 Ti2C and MoS2 Ti2CY2 (Y=F and OH) all-2D semiconductor metal contacts.pdf (2.55 MB)

Type

Article

Authors

Gan, Liyong
Huang, Dan
Schwingenschlögl, Udo

Zhao, Yu-Jun

KAUST Department

Computational Physics and Materials Science (CPMS)
Material Science and Engineering Program
Physical Science and Engineering (PSE) Division

Date

2013-06-13

Abstract

First-principles calculations are used to explore the geometry, bonding, and electronic properties of MoS2/Ti2C and MoS2/Ti2CY2 (Y = F and OH) semiconductor/metal contacts. The structure of the interfaces is determined. Strong chemical bonds formed at the MoS2/Ti2C interface result in additional states next to the Fermi level, which extend over the three atomic layers of MoS2 and induce a metallic character. The interaction in MoS2/Ti2CY2, on the other hand, is weak and not sensitive to the specific geometry, and the semiconducting nature thus is preserved. The energy level alignment implies weak and strong n-type doping of MoS2 in MoS2/Ti2CF2 and MoS2/Ti2C(OH)2, respectively. The corresponding n-type Schottky barrier heights are 0.85 and 0.26 eV. We show that the MoS2/Ti2CF2 interface is close to the Schottky limit. At the MoS2/Ti2C(OH)2 interface, we find that a strong dipole due to charge rearrangement induces the Schottky barrier. The present interfaces are well suited for application in all-two-dimensional devices.

Citation

Gan L-Y, Zhao Y-J, Huang D, Schwingenschlögl U (2013) First-principles analysis of MoS2/Ti2C and MoS2/Ti2CY2 (Y=F and OH) all-2D semiconductor/metal contacts. Phys Rev B 87. doi:10.1103/PhysRevB.87.245307