Analysis of ternary AlGaX <sub>2</sub> (X = As, Sb) compounds for opto-electronic and renewable energy devices using density functional theory
Muhammad Waqas Iqbal, Mazia Asghar, N.A. Noor, Hamid Ullah, Tausif Zahid, Sikandir Aftab, Asif Mahmood
Abstract
Abstract Based on the First-principles calculations, we have investigated the opto-electronic properties of AlGaX 2 (X = As, Sb). We find that the AlGaX 2 (X = As, Sb) is energetically stable due to lower formation enthalpy. Additionally, the dynamical stability is also confirmed by phonon calculation and found no-imaginary frequencies in the phonon-spectra. Interestingly, both AlGaAs 2 and AlGaSb 2 compounds possesses semiconductor nature with a direct bandgap of 1.40 eV and 0.70 eV, respectively. For the technological applications of AlGaX 2 (X = As, Sb), we have analyzed optical properties in terms of absorption of photon energy and polarization. A strong absorption peaks are observed in the visible region. Moreover, the thermoelectric properties are calculated in terms of electrical/thermal conductivities, Seebeck coefficient, and figure of merit (ZT). Thermal parameters are critical for determining a material’ thermal stability across the wide range of temperatures. We expect that our calculated properties of AlGaAs 2 and AlGaSb 2 compounds could pave a new route for the applications in the optoelectronics and thermoelectric devices.