Direct observation of the band structure in bulk hexagonal boron nitride Auteur(s): Henck Hugo, Pierucci Debora, Fugallo Giorgia, Avila Jose, Cassabois G., Dappe Yannick J., Silly Mathieu G., Chen Chaoyu, Gil B., Gatti Matteo, Sottile Francesco, Sirotti Fausto, Asensio Maria C., Ouerghi Abdelkarim (Article) Publié: Physical Review B, vol. 95 p.085410 (2017) Ref HAL: hal-01487020_v1 DOI: 10.1103/PhysRevB.95.085410 WoS: WOS:000393501300005 Exporter : BibTex | endNote 32 Citations Résumé: A promising route towards nanodevice applications relies on the association of graphene and transition metal dichalcogenides with hexagonal boron nitride (h-BN). Due to its insulating nature, h-BN has emerged as a natural substrate and gate dielectric for graphene-based electronic devices. However, some fundamental properties of bulk h-BN remain obscure. For example, the band structure and the position of the Fermi level have not been experimentally resolved. Here, we report a direct observation of parabolic dispersions of h-BN crystals using high-resolution angle-resolved photoemission spectroscopy (ARPES). We find that h-BN exfoliation on epitaxial graphene enables overcoming the technical difficulties of using ARPES with insulating materials. We show trigonal warping of the intensity maps at constant energy. The valence-band maxima are located around the K points, 2.5 eV below the Fermi level, thus confirming the residual p-type character of typical h-BN. |