Electronic and optical properties of AlxGayIn1-x-yAs quaternary alloys with and without relaxation lattice matched to InP for laser applications: First-principles study

In this paper, the (FP-LAPW) calculations based on density functional theory (DFT) have been performed. To study the structural, electronic and optical properties of the AlxGayIn1-x-yAs/InP with a number of compositions (0.03125 <= x <= 0.40625 and 1 - x - y = 0.53125). The (GGA-WC) of Wu and Cohen has been used to calculate the structural properties while the (GGA-BPEsol) and (GGA-EV) of Engel and Vodka as well as the recently (TB-mBJ) are employed to calculate the electronic properties of AlxGayIn1-x-yAs with and without relaxation. It is found that the lattice constant of the AlxGayIn1-x-yAs/InP alloy are almost identical. It is also observed that the lattice constant of the AlxGayIn1-x-yAs alloys can be controlled by In concentration while the band gap can be adjusted by Al concentration. The calculated band structures show that the quaternary AlxGayIn1-x-yAs/InP are direct-gap semiconductors for all Al concentrations x (0.03125 <= x <= 0.40625). Moreover, this band gap exhibits small bowing parameters. The results for optical properties are also discussed in detail. We have compared the results obtained to the existing theoretical and experimental data. The calculation endorses that the AlxGayIn1-x-yAs/InP compound is a promising candidate for optoelectronics. (C) 2016 Elsevier GmbH. All rights reserved.