Author(s): Qiu, C (Qiu, Chen); Zhang, C (Zhang, Chen); Geng, SY (Geng, Songyuan); Wang, F (Wang, Fei); Deng, HX (Deng, Hui-Xiong)

Source: JOURNAL OF PHYSICAL CHEMISTRY C DOI: 10.1021/acs.jpcc.2c05131 Early Access Date: SEP 2022

Abstract: Monolayer (ML) MoSe2 and WSe2 are promising materials for novel two-dimensional high-performance electronic and optoelectronic devices. Although ML MoSe2 and WSe2 possess the same crystal structure and similar chemical composition and band gap, they are experimentally observed to have distinct carrier types in conduction, i.e., ML MoSe2 is usually a n-type and ML WSe2 usually a p-type semiconductor. The reasons for such distinction are not fully understood so far. In this paper, by first-principles systematic investigation of the properties of intrinsic point defects and some inevitable unintentional extrinsic impurities under normal growth environments for ML MoSe2 and WSe2, we find that intrinsic defects are neither efficient p-type nor n-type dopants in these materials. Instead, hydrogen interstitial (H-i(inside)) is a shallow donor in both ML MoSe2 and WSe2, while nitrogen-substituting host selenium (NSe) is a relatively shallow acceptor in both ML MoSe2 and WSe2. However, in the presence of both H and N doping, the compensation between the two type dopants pinned the Fermi energy close to the conduction band edge for ML MoSe2 and close to the valence band edge for ML WSe2. Our study, therefore, provides insights into the origin of the distinct types of conduction of ML MoSe2 and WSe2 and provides guidelines on how to dope transition metal dichalcogenides.

Accession Number: WOS:000859279300001

Author Identifiers:

Author        Web of Science ResearcherID        ORCID Number

Wang, Fei                  0000-0002-3442-9396

ISSN: 1932-7447

eISSN: 1932-7455

Full Text: https://pubs.acs.org/doi/10.1021/acs.jpcc.2c05131