Valley phenomena in the candidate phase change material WSe2(1-x)Te2x.
Commun Phys
; 32020.
Article
em En
| MEDLINE
| ID: mdl-33225081
ABSTRACT
Alloyed transition metal dichalcogenides provide an opportunity for coupling band engineering with valleytronic phenomena in an atomically-thin platform. However, valley properties in alloys remain largely unexplored. We investigate the valley degree of freedom in monolayer alloys of the phase change candidate material WSe2(1-x)Te2x. Low temperature Raman measurements track the alloy-induced transition from the semiconducting 1H phase of WSe2 to the semimetallic 1Td phase of WTe2. We correlate these observations with density functional theory calculations and identify new Raman modes from W-Te vibrations in the 1H-phase alloy. Photoluminescence measurements show ultra-low energy emission features that highlight alloy disorder arising from the large W-Te bond lengths. Interestingly, valley polarization and coherence in alloys survive at high Te compositions and are more robust against temperature than in WSe2. These findings illustrate the persistence of valley properties in alloys with highly dissimilar parent compounds and suggest band engineering can be utilized for valleytronic devices.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Commun Phys
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Estados Unidos