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Quasiparticle electronic structure of barium-silicon oxynitrides for white-LED application

Bertrand, B. ; Poncé, S. ; Waroquiers, D. ; Stankovski, M. LU ; Giantomassi, M. ; Mikami, M. and Gonze, X. (2013) In Physical Review B - Condensed Matter and Materials Physics 88(7).
Abstract

Ba3Si6O12N2:Eu2+ and Ba3Si6O9N4:Eu2+ have strikingly similar atomistic structures, but the former is an efficient green phosphor at working temperature while the latter is a bluish-green phosphor whose luminescence decreases quite fast with temperature. Aiming at the understanding of such different behavior, we compute the quasiparticle electronic band structure of the two hosts, Ba3Si6O 12N2 and Ba3Si6O9N 4, thanks to many-body perturbation theory in the G0W 0 approximation. The gap differs by about 0.43 eV. We analyze... (More)

Ba3Si6O12N2:Eu2+ and Ba3Si6O9N4:Eu2+ have strikingly similar atomistic structures, but the former is an efficient green phosphor at working temperature while the latter is a bluish-green phosphor whose luminescence decreases quite fast with temperature. Aiming at the understanding of such different behavior, we compute the quasiparticle electronic band structure of the two hosts, Ba3Si6O 12N2 and Ba3Si6O9N 4, thanks to many-body perturbation theory in the G0W 0 approximation. The gap differs by about 0.43 eV. We analyze the eigenfunctions at the top of the valence band, at the bottom of the conduction band, and also the chemical shifts for the Ba site in the two hosts. The valence bands, directly impacted by the different stoichiometric ratio, are not thought to play a large role in the luminescence. Deceivingly, the dispersive bottom of the conduction band, directly related to luminescent properties, is similar in both compounds. The spatial topology of the probability density of the bottom of the conduction bands differs, as well as the location of the 5d peak, with a much higher energy than the bottom of the conduction band in Ba 3Si6O12N2 than in Ba 3Si6O9N4. Electromagnetic absorption spectra are also computed for both compounds.

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author
; ; ; ; ; and
publishing date
type
Contribution to journal
publication status
published
in
Physical Review B - Condensed Matter and Materials Physics
volume
88
issue
7
article number
075136
publisher
American Physical Society
external identifiers
  • scopus:84884508283
ISSN
1098-0121
DOI
10.1103/PhysRevB.88.075136
language
English
LU publication?
no
id
ed3d2439-e2f9-41e3-beb4-9cf390f6b188
date added to LUP
2019-03-06 14:47:32
date last changed
2022-02-23 00:32:50
@article{ed3d2439-e2f9-41e3-beb4-9cf390f6b188,
  abstract     = {{<p>Ba<sup>3</sup>Si<sup>6</sup>O<sup>12</sup>N<sup>2</sup>:Eu2<sup>+</sup> and Ba<sup>3</sup>Si<sup>6</sup>O<sup>9</sup>N<sup>4</sup>:Eu2<sup>+</sup> have strikingly similar atomistic structures, but the former is an efficient green phosphor at working temperature while the latter is a bluish-green phosphor whose luminescence decreases quite fast with temperature. Aiming at the understanding of such different behavior, we compute the quasiparticle electronic band structure of the two hosts, Ba<sup>3</sup>Si<sup>6</sup>O <sup>12</sup>N<sup>2</sup> and Ba<sup>3</sup>Si<sup>6</sup>O<sup>9</sup>N <sup>4</sup>, thanks to many-body perturbation theory in the G<sub>0</sub>W <sub>0</sub> approximation. The gap differs by about 0.43 eV. We analyze the eigenfunctions at the top of the valence band, at the bottom of the conduction band, and also the chemical shifts for the Ba site in the two hosts. The valence bands, directly impacted by the different stoichiometric ratio, are not thought to play a large role in the luminescence. Deceivingly, the dispersive bottom of the conduction band, directly related to luminescent properties, is similar in both compounds. The spatial topology of the probability density of the bottom of the conduction bands differs, as well as the location of the 5d peak, with a much higher energy than the bottom of the conduction band in Ba <sup>3</sup>Si<sup>6</sup>O<sup>12</sup>N<sup>2</sup> than in Ba <sup>3</sup>Si<sup>6</sup>O<sup>9</sup>N<sup>4</sup>. Electromagnetic absorption spectra are also computed for both compounds.</p>}},
  author       = {{Bertrand, B. and Poncé, S. and Waroquiers, D. and Stankovski, M. and Giantomassi, M. and Mikami, M. and Gonze, X.}},
  issn         = {{1098-0121}},
  language     = {{eng}},
  month        = {{08}},
  number       = {{7}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review B - Condensed Matter and Materials Physics}},
  title        = {{Quasiparticle electronic structure of barium-silicon oxynitrides for white-LED application}},
  url          = {{http://dx.doi.org/10.1103/PhysRevB.88.075136}},
  doi          = {{10.1103/PhysRevB.88.075136}},
  volume       = {{88}},
  year         = {{2013}},
}