Structural, electronic and optical properties of layered GaSe1-xAsx

We report first-principle calculations of the structural, electronic and optical properties of beta-GaSe under substitutional doping of arsenic with selenium within density functional theory. We find that the band gap not only decreases with doping concentration but also depends on the substitutional sites of Se. In addition, the substitution of As on Se-site create doping energy levels, just above the Fermi level, suggest the p-type semi-conducting behavior. Moreover, from the optical studies we observed that GaSe1-xAsx are good absorber of ultraviolet radiation while beta-GaAs shows the strong absorption in visible region indicate that GaSe1-xAsx can have potential application in optoelectronic devices. (C) 2017 Elsevier B.V. All rights reserved.