Origin of the  n  -type and  p  -type conductivity of MoS    2   monolayers on a SiO    2   substrate

Dolui, Kapildeb; Rungger, Ivan; Sanvito, Stefano

Origin of the n -type and p -type conductivity of MoS 2 monolayers on a SiO 2 substrate

Type

Article

Authors

Dolui, Kapildeb
Rungger, Ivan
Sanvito, Stefano

Date

2013-04-02

Abstract

Ab initio density functional theory calculations are performed to study the electronic properties of a MoS2 monolayer deposited over a SiO 2 substrate in the presence of interface impurities and defects. When MoS2 is placed on a defect-free substrate, the oxide plays an insignificant role since the conduction band top and the valence band minimum of MoS2 are located approximately in the middle of the SiO2 band gap. However, if Na impurities and O dangling bonds are introduced at the SiO2 surface, these lead to localized states, which modulate the conductivity of the MoS2 monolayer from n- to p-type. Our results show that the conductive properties of MoS2 deposited on SiO 2 are mainly determined by the detailed structure of the MoS 2/SiO2 interface, and suggest that doping the substrate can represent a viable strategy for engineering MoS2-based devices. © 2013 American Physical Society.

Citation

Dolui K, Rungger I, Sanvito S (2013) Origin of the n -type and p -type conductivity of MoS 2 monolayers on a SiO 2 substrate . Physical Review B 87. Available: http://dx.doi.org/10.1103/PhysRevB.87.165402.

Acknowledgements

This work is supported by Science Foundation of Ireland (Grant No. 07/IN.1/I945) and by CRANN. I.R. acknowledges financial support from the King Abdullah University of Science and Technology (acrab project). We thank Trinity Centre for High Performance Computing (TCHPC) for the computational resources provided.