Bowing parameters for zinc-blende Al1−xGaxN and Ga1−xInxN

Abstract

First-principles calculations have been used to determine bowing parameters for disordered zinc-blende Al1−xGaxN and Ga1−xInxN. The direct transition at Γ is found to bow downward for both materials with parameters +0.53 and +1.02 eV, respectively, while the Γ-to-X transition bows upward for Al1−xGaxN (parameter −0.10 eV) and downward for Ga1−xInxN (parameter +0.38 eV). The similarity of the calculated bulk zinc-blende and wurtzite Γ-point transitions also allows estimates to be made of the energy gap versus composition for wurtzite alloys.

High Al-Content AlInGaN Devices for Next Generation Electronic and Optoelectronic Applications

“…Our results in Fig. 10 are compared with measurements on unstrained zinc-blende InGaN and our previous theoretical results for zinc-blende InGaN [36]. The calculated wurtzite and zinc-blende gap deviations are in good agreement, providing confidence in the often made assumption that nitride alloys having these two structures should have similar band-gap bowing.…”

“…The Brillouin zone was sampled using the G-point, and tests using Monkhorst-Pack [35] parameters {2,2,2} verified the adequacy of this sampling. For theoretical zinc-blende InGaN results and further discussions related to using DFT-LDA for alloy calculations, we refer to our earlier publication [36,37].…”

“…PL investigation of the near band-edge emission is summarized by the dashed curves (denoting contours of constant PL peak energy) in Figure 16. The dashed contours are derived based on two assumptions: i) all the data points should be fitted by contours with nearly identical forms, and ii) the contours should be consistent with the available (theoretical [65] and experimental [66]) bowing information of ternary AlInN. Along each dashed line, the emission wavelength remains constant while the in-plane lattice parameter (and therefore strain) can be adjusted by varying the Al and In fractions.…”

Hybrid functional investigations of band gaps and band alignments for AlN, GaN, InN, and InGaN

“…The various experimental [45][46][47][48][49][50][51][52][53] as well as theoretical [54][55][56][57][58][59][60][61][62][63][64] studies have disagreed on the magnitude of the bowing parameter.…”

Compositional dependence of the strain-free optical band gap in InxGa1−xN layers

“…A deviation from a linear dependence of the fundamental gap has been postulated, with a wide range of bowing parameters, in the literature. [6][7][8][9][10][11][12][13][14] Several sources of error hamper the establishment of a consensual relation. In some studies the measured quantity is the luminescence peak energy, with ignores the Stokes' shifted 15,16 of emission with respect to the band edge.…”