Abstract
When serving as a protection tissue and/or inducing a periodic lateral modulation
for/in atomically thin crystals, hexagonal boron nitride, hBN, has revolutionised the
research on van der Waals heterostructures. By itself, hBN appears as an emergent
wide-bandgap material which, importantly, can be optically bright in the far UV range
and which frequently displays mid-gap defect-related centres of yet unclear origin but, interestingly, acting as single photon emitters. Controlling the hBN doping is of
particular interest in view of the possible practical use of this material. Here we
demonstrate that enriching hBN with carbon (C) activates an optical response of this
material in form of a series of well-defined resonances in visible and near-infrared
region, which appear in the luminescence spectra measured under below-bandgap
excitation. Two, qualitatively different C-related radiative centres are identified: one
follows the Franck-Condon principle that describes transitions between two defect
states with emission/annihilation of optical phonons and the other shows atomic-like
resonances characteristic of intra-defect transitions. With a detailed characterisation
of the energy structure and emission dynamics of these radiative centres we
contribute to development of the controlled doping of hBN with mid-gap centres.
for/in atomically thin crystals, hexagonal boron nitride, hBN, has revolutionised the
research on van der Waals heterostructures. By itself, hBN appears as an emergent
wide-bandgap material which, importantly, can be optically bright in the far UV range
and which frequently displays mid-gap defect-related centres of yet unclear origin but, interestingly, acting as single photon emitters. Controlling the hBN doping is of
particular interest in view of the possible practical use of this material. Here we
demonstrate that enriching hBN with carbon (C) activates an optical response of this
material in form of a series of well-defined resonances in visible and near-infrared
region, which appear in the luminescence spectra measured under below-bandgap
excitation. Two, qualitatively different C-related radiative centres are identified: one
follows the Franck-Condon principle that describes transitions between two defect
states with emission/annihilation of optical phonons and the other shows atomic-like
resonances characteristic of intra-defect transitions. With a detailed characterisation
of the energy structure and emission dynamics of these radiative centres we
contribute to development of the controlled doping of hBN with mid-gap centres.
| Original language | English |
|---|---|
| Journal | Proceedings of the National Academy of Sciences |
| Publication status | Accepted/In press - 15 Apr 2020 |