Transition-metal dichalcogenides with type-II Dirac fermions: Surface properties and application capabilities

D’Olimpio, G. (2020) Transition-metal dichalcogenides with type-II Dirac fermions: Surface properties and application capabilities. Il nuovo cimento C, 43 (4-5). pp. 1-10. ISSN 1826-9885

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Abstract

Among the various layered materials “beyond graphene”, the class of transition-metal dichalcogenides MTe2 (M= Ni, Pd, Pt) is particularly interesting, due to the existence of bulk type-II Dirac fermions, arising from a tilted Dirac cone. The Dirac cone in these materials is located in the bulk, with inherently superior robustness to surface modifications compared to other Dirac materials, among which graphene, topological insulator and silicene. In addition, MTe2 also displays application capabilities in optoelectronics and catalysis. Here, with surfacescience experiments and theory, we assess the surface properties of MTe2, including i) ambient stability, ii) chemical reactivity and iii) aging mechanisms. Remarkably, MTe2 shows outstanding tolerance to CO and stability in water environment. We also demonstrate that passivation in ambient atmosphere is achieved in less than 30 minutes with the TeO2 skin having a sub-nanometric thickness even after one year in the air. The existence of Te vacancies leads to the enhancement of the surface chemical reactivity. These results pave the way toward the exploitation of this class of Dirac materials in optoelectronics and catalysis.

Item Type:	Article
Subjects:	500 Scienze naturali e Matematica > 530 Fisica
Depositing User:	Marina Spanti
Date Deposited:	18 Mar 2021 09:02
Last Modified:	18 Mar 2021 09:02
URI:	http://eprints.bice.rm.cnr.it/id/eprint/20847

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