Hybrid density functional study of optically active Er${}^{3+}$ centers in GaN

Abstract

Understanding the luminescence of GaN doped with erbium (Er) requires a detailed knowledge of the interaction between the rare-earth dopant and the nitride host, including intrinsic defects and other impurities that may be present in the host material. We address this problem through a first-principles hybrid density functional study of the structure, energetics, and transition levels of the Er impurity and its complexes with N and Ga vacancies, substitutional C and O impurities, and H interstitials in wurtzite GaN. We find that, in the interior of the material, Er${}_{\mathrm{Ga}}$ is the dominant Er${}^{3+}$ center with a formation energy of 1.55 eV; Er${}_{\mathrm{Ga}}$-$V_{\mathrm{N}}$ possesses a deep donor level at 0.61 eV which can assist in the transfer of energy to the 4$f$-electron core. Multiple optically active Er${}^{3+}$ centers are possible in Er-doped GaN.

4 pages, 3 figures; minor changes. in Phys. Status Solidi RRL (2015)

References in corpus (1)

• Electronic structure of rare-earth impurities in GaAs and GaN

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