Band gap measurements of monolayer h-BN and insights into carbon-related point defects - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Article Dans Une Revue 2D Materials Année : 2021

Band gap measurements of monolayer h-BN and insights into carbon-related point defects

Résumé

Being a flexible wide band gap semiconductor, hexagonal boron nitride (h-BN) has great potential for technological applications like efficient deep ultraviolet light sources, building block for two-dimensional heterostructures and room temperature single photon emitters in the ultraviolet and visible spectral range. To enable such applications, it is mandatory to reach a better understanding of the electronic and optical properties of h-BN and the impact of various structural defects. Despite the large efforts in the last years, aspects such as the electronic band gap value, the exciton binding energy and the effect of point defects remained elusive, particularly when considering a single monolayer. Here, we directly measured the density of states of a single monolayer of h-BN epitaxially grown on highly oriented pyrolytic graphite, by performing low temperature scanning tunneling microscopy (STM) and spectroscopy (STS). The observed h-BN electronic band gap on defect-free regions is (6.8 ± 0.2) eV. Using optical spectroscopy to obtain the h-BN optical band gap, the exciton binding energy is determined as being of (0.7 ± 0.2) eV. In addition, the locally excited cathodoluminescence and photoluminescence show complex spectra that are typically associated to intragap states related to carbon defects. Moreover, in some regions of the monolayer h-BN we identify, using STM, point defects which have intragap electronic levels around 2.0 eV below the Fermi level.
Fichier principal
Vignette du fichier
Monolayer h-BN on HOPG - Main text Review1 - Marked lowRes_1_.pdf (1022.3 Ko) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-03374011 , version 1 (23-01-2024)

Identifiants

Citer

Ricardo Javier Pena Roman, Fabio J. R. Costa Costa, Alberto Zobelli, Christine Elias, Pierre Valvin, et al.. Band gap measurements of monolayer h-BN and insights into carbon-related point defects. 2D Materials, 2021, 8 (4), pp.044001. ⟨10.1088/2053-1583/ac0d9c⟩. ⟨hal-03374011⟩
61 Consultations
9 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More