Accurate band gaps of AlGaN, InGaN, and AlInN alloys calculations based on LDA-1/2 approach

Abstract

We present parameter-free calculations of electronic properties of InGaN, InAlN, and AlGaN alloys. The calculations are based on a generalized quasichemical approach, to account for disorder and composition effects, and first-principles calculations within the density functional theory with the LDA-1/2 approach, to accurately determine the band gaps. We provide precise results for AlGaN, InGaN, and AlInN band gaps for the entire range of compositions, and their respective bowing parameters.

Polarization Effects of GaN and AlGaN: Polarization Bound Charge, Band Bending, and Electronic Surface States

“…where E C was the position of the conduction band with respect to the Fermi level as determined by the doping density (À0.1 eV), E g was the band gap of the material (E g,GaN = 3.4 eV and E g,AlGaN = 4.0 eV 30 ), and E Cl, XPS was the position of the Ga 3d core level for GaN and Al 2p core level for AlGaN. It is worth noting here that this analysis focused on the Ga 3d peak, where the core level intensity and position were less sensitive to the overlayer, thereby providing more reliable band bending measurements.…”

Atomistic analysis of the impact of alloy and well-width fluctuations on the electronic and optical properties of InGaN/GaN quantum wells

“…Previous atomistic calculations have mainly focused on ZB [9][10][11] or WZ [12][13][14][15] InGaN bulk alloys. Properties of WZ InGaN/GaN QWs with realistic dimensions are typically studied using continuumbased theoretical models, which inherently overlook alloy or built-in field fluctuations on a microscopic level.…”

GaMnAs: Position of Mn-d levels and majority spin band gap predicted from GGA-1/2 calculations

“…Lately we have been also using a GGA-1/2 method, where the exchange-correlation is GGA, instead of LDA, and the À1/2 is to remind that we remove 1/2 electron, as in the transition state technique. LDA-1/2 and also GGA-1/2 have proven to describe correctly the excitation aspects in binary compounds, 17,18 alloys, 19 and interfaces. 20 In this article, we perform ab initio calculations based on DFT using both GGA-1/2 and GGA for the XC potential to contrast the results.…”