Eur. Phys. J. B (2014) 87: 159
https://doi.org/10.1140/epjb/e2014-41097-2

Regular Article

Structural, electronic, optical, elastic and thermal properties of ZnXAs₂ (X = Si and Ge) chalcopyrite semiconductors

¹ Department of Physics, Banasthali Vidyapith, Rajasthan 304022, India
² Department of Physics, Panjab University, Chandigarh 160014, India

^a e-mail: ajay_phy@rediffmail.com

Received: 21 December 2013
Received in final form: 13 April 2014
Published online: 23 July 2014

Abstract

We report first principles calculations of solid state properties of ZnSiAs₂ and ZnGeAs₂ chalcopyrite semiconductors. The structural properties are calculated using a Full Potential Linearized Augmented Plane Wave method (FP-LAPW) of the Density Functional Theory (DFT). A Generalized Gradient Approximation (GGA) scheme proposed by Wu and Cohen (WC) has been chosen to calculate electronic and optical properties. Optical features such as dielectric functions, refractive indices, extinction coefficient, optical reflectivity, absorption coefficients and optical conductivities were calculated for photon energies up to 30 eV. The elastic constants at equilibrium in tetragonal structure are also determined. Temperature effect on the volume, thermal expansion, heat capacity, Debye temperature, entropy, Grüneisen parameter and bulk modulus were calculated employing the quasi-harmonic Debye model at different temperatures and pressures and the silent results were interpreted. Finally using semi-empirical relation, we determined the hardness of the materials which attributed to different covalent bonding strengths.