Origin of n-type conductivity of monolayer MoS2

Singh, Akash and Singh, Abhishek Kumar (2019) Origin of n-type conductivity of monolayer MoS2. In: PHYSICAL REVIEW B, 99 (12).

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Abstract

Monolayer MoS2 is a promising two-dimensional material for electronic and optoelectronic devices. As-grown MoS2 is an n-type semiconductor, however, the origin of this unintentional doping is still not clear. Here, using hybrid density functional theory, we carried out an extensive study of the often observed native point defects, i.e., V-S, V-Mo, V-S2, V-MoS3, V-MoS6, Mo-S2, and S2(Mo), and found that none of them cause n-type doping. Specifically, the S vacancy (V-S), which has been widely attributed to n-type conductivity, turns out to be an electron compensating center. We report that hydrogen, which is almost always present in the growth environments, is most stable in its interstitial (H-i) and H-S adatom forms in MoS2 and acts as a shallow donor, provided the sample is grown under S-rich condition. Furthermore, they have high migration barriers (in excess of 1 eV), which would ensure their stability even at higher temperatures, and hence lead to n-type conductivity.

Item Type:	Journal Article
Publication:	PHYSICAL REVIEW B
Publisher:	AMER PHYSICAL SOC,
Additional Information:	Copyright belongs to AMER PHYSICAL SOC,
Keywords:	TRANSITION-METAL DICHALCOGENIDES;TOTAL-ENERGY CALCULATIONS; FEW-LAYER MOS2;DEFECTS
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	23 Apr 2019 04:46
Last Modified:	25 Sep 2022 05:58
URI:	https://eprints.iisc.ac.in/id/eprint/62476

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