Optical properties of magnesium doped AlxGa1−xN (0.61 ≤ x ≤ 0.73)

Abstract

We investigate the optical properties of Al x Ga 1-x N:Mg with aluminum content of 0.61 x 0.733 in comparison to undoped and silicon doped reference samples. The ordinary dielectric functions, excitation, and emission spectra are reported at different temperatures. A comprehensive analysis yields quantitative data on the valence band structure of the ternary alloy, i.e., splitting and order of valence bands with different symmetries. Finally, the near band gap emission in AlGaN:Mg is found to be most probably dominated by donor to free-hole recombination. V C 2014 AIP Publishing LLC. [http://dx

Looking for Auger signatures in III-nitride light emitters: A full-band Monte Carlo perspective

“…In order to place the question fairly before the reader, it should be mentioned that these first-principles studies are validated by a large body of experimental work on the highenergy critical points of GaN (van Hove singularities) measured by spectroscopic ellipsometry. 16,[32][33][34][35][36][37][38] Ellipsometric measurements provide a reliable estimate of 2.6 eV for the C-L energy separation, as fully confirmed by the quasiparticle electronic structure calculations reported by de Carvalho et al 39 when excitonic effects are included by solving the Bethe-Salpeter equation. 40 If we were to question the assignment of the energy transitions to the critical points of the dielectric functions in GaN, we should also reconsider optical studies of AlN 35 and AlGaN alloys 38 that demonstrate the continuous change of the higher energy features.…”

“…16,[32][33][34][35][36][37][38] Ellipsometric measurements provide a reliable estimate of 2.6 eV for the C-L energy separation, as fully confirmed by the quasiparticle electronic structure calculations reported by de Carvalho et al 39 when excitonic effects are included by solving the Bethe-Salpeter equation. 40 If we were to question the assignment of the energy transitions to the critical points of the dielectric functions in GaN, we should also reconsider optical studies of AlN 35 and AlGaN alloys 38 that demonstrate the continuous change of the higher energy features. Studies of highly doped GaN did not provide any indication of renormalization effects for transitions related to high energy critical points, let alone low satellite valleys in the conduction band.…”