%0 Conference Paper
%F Oral 
%T Unraveling the bandgap nature in hexagonal boron nitride
%+ Laboratoire Charles Coulomb (L2C)
%A Cassabois, Guillaume
%F Invité
%< sans comité de lecture
%Z L2C:16-114
%B IW2DC
%C Campofelice di Roccella, Italy
%8 2016-05-30
%D 2016
%Z Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other]Conference papers
%X I will discuss our recent experiments by two-photon spectroscopy demonstrating that hBN is an indirect bandgap material. I will show that the optical properties of hBN are profoundly determined by phonon-assisted transitions involving either virtual or real excitonic states. I will present our measurements of the exciton binding energy by two-photon excitation, leading to the estimation of 6.08 eV for the single-particle bandgap in hBN. I will also show that transverse optical phonons at the K point of the Brillouin zone assist intervalley scattering, which becomes observable because stacking faults in bulk hexagonal boron nitride provide a density of final electronic states.
%G English
%L hal-01358450
%U https://hal.science/hal-01358450
%~ CNRS
%~ L2C
%~ MIPS
%~ UNIV-MONTPELLIER
%~ UM-2015-2021