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Defect-induced exciton localization in bulk gallium nitride from many-body perturbation theory

MetadataDetails
Publication Date2019-11-21
JournalPhysical Review Materials
AuthorsD. Kirk Lewis, Sahar Sharifzadeh
InstitutionsBoston University
Citations13

We present a many-body perturbation theory study of the excitonic properties of wurtzite GaN containing a single charged nitrogen vacancy. We determine that the lowest-energy exciton consists of a bulk to defect transition, resulting in a slight redshift (<0.1 eV) of the optical absorption onset and a 50 meV increase in the exciton binding energy when compared with pristine bulk. Furthermore, by analysis of the electron-hole correlation function, we quantify the defect-induced localization of the Wannier-Mott exciton in two ways. First, we show that the electron-hole separation is reduced, and that the exciton envelope wave function can be related to a simple model of a defect-bound exciton. Second, we show that the exciton center-of-mass does not display the periodicity of the lattice due to defect-induced localization. We anticipate that our approach, which quantitatively describes the influence of a point defect on the exciton wave function, will be generally applicable.

  1. 2009 - Charged Semiconductor Defects: Structure, Thermodynamics and Diffusion [Crossref]
  2. 2017 - Semicond. Semimetals
  3. 2015 - Point Defects in Silicon Carbide [Crossref]