Band gap bowing and spectral width of Ga(1−x)InxN alloys for modelling light emitting diodes

Christian Tantardini, Xavier Gonze

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Ga(1−x)InxN alloys, widely employed to produce light-emitting diodes, exhibit a bowing of the band gap as a function of concentration x, and a luminescence spectral width which differs from the expected value of 1.8 kT. Through first-principles calculations, based on many-body perturbation theory and density-functional theory with a meta-GGA exchange–correlation functional, we explore jointly these effects, in an exhaustive set of Ga(1−x)InxN supercells with 16 atoms. We disentangle the bowing due to the average volume change with the one due local atomic configuration and local relaxation. The first one account for about 40% of the bowing, despite that fact that the change of volume with respect to concentration is nearly linear (Vegard's law). The computed bowing parameter is 1.39 eV. The experimental broadening between 3 kT and 8 kT, not examined theoretically until now, is well accounted by local atomic configuration changes and lifting of the degeneracy of the top of the valence band.

Original languageEnglish
Article number413481
JournalPhysica B: Condensed Matter
Volume625
DOIs
Publication statusPublished - 15 Jan 2022

Keywords

  • Band gap
  • Bowing
  • DFT
  • Ga-In nitrides
  • GW

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