%0 Journal Article
%T The Determination of the Optical Bandgap of the Bernal and Rhombohedral Boron Nitride Polymorphs
%+ Laboratoire Charles Coulomb (L2C)
%+ S2QT
%+ PV2D
%+ Kansas State University
%A Rousseau, Adrien
%A Moret, Matthieu
%A Valvin, Pierre
%A Desrat, Wilfried
%A Li, Jiahan
%A Xue, Lianjie
%A Janzen, E.
%A Edgar, James
%A Cassabois, Guillaume
%A Gil, Bernard
%< avec comité de lecture
%Z L2C:21-058
%@ 2475-9953
%J Physical Review Materials
%I American Physical Society
%V 5
%P 064602
%8 2021-06-17
%D 2021
%R 10.1103/PhysRevMaterials.5.064602
%Z Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other]
%Z Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]Journal articles
%X We report a study of polymorphic boron nitride samples. We interpret the photoluminescence line at 6.032±0.005 eV, that can be recorded at 8K in sp2-bonded boron nitride, as being the signature of the excitonic fundamental bandgap of the Bernal (or graphitic) boron nitride polymorph (bBN). This is determined by advanced photoluminescence measurements combined with x-ray characterizations on pure hexagonal boron nitride (hBN) and on polymorphic crystal samples, later compared with the theoretical predictions of Lorenzo Sponza, et al., Physical Review B 98, 125206 (2018). The overall picture is consistent with a direct excitonic fundamental bandgap of the Bernal (or graphitic) polymorph of boron nitride. This value dXb = 6.032±0.005 eV is higher than the indirect bandgap of hBN (iXh =5.955±0.005 eV).
%G English
%L hal-03263151
%U https://hal.science/hal-03263151
%~ CNRS
%~ L2C
%~ MIPS
%~ UNIV-MONTPELLIER
%~ ANR
%~ UM-2015-2021