Electronic properties of rhombohedrally stacked bilayer W Se 2 obtained by chemical vapor deposition
Résumé
Twisted layers of atomically thin two-dimensional materials support a broad range of quantum materials with engineered optical and transport properties. Transition metal dichalcogenides (TMDs) in the rhombohedral (3R, i.e., 0 • twist) crystal phase have been the focus of significant research interest in optical applications due to their particular broken inversion symmetry. Here, we report experimental and theoretical study of WSe 2 homobilayers obtained in stable 3R configuration by chemical vapor synthesis. We investigate the electronic and structural properties of these 3R WSe 2 bilayers with 3R stacking using micro-Raman spectroscopy, angleresolved photoemission nanospectroscopy measurements, and density functional theory calculations. Our results demonstrate that WSe 2 bilayers with 3R crystal phase (AB stacking) show a significant valence-band splitting at the K point estimated at 550 ± 20 meV. We derived experimentally effective hole masses of 0.48m e and 0.73m e at the K point for upper and lower bands, respectively. Our work opens up perspectives for the development of optoelectronic and spintronic devices based on 3R TMD homobilayers.
Domaines
Physique [physics]| Origine | Fichiers produits par l'(les) auteur(s) |
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