Ab-initio study of Electronic, Optical, Dynamic and Thermoelectric properties of CuSbX۲ (X=S,Se) compounds

Abstract: In this work we investigate the electronic, optical, dynamic and thermoelectric properties of ternary copper-based Chalcogenides CuSbX۲ (X= S, Se) compounds. Calculations are based on density functional theory and the semi-classical Boltzmann theory. Computations have been carried out by using Quantum-Espresso (PWSCF) package and ab-initio pseudo-potential technique. To estimate the exchange-correlation functional various approximations were used,which among them GGA approximation led to better results. Density of state calculations indicates that CuSbSe۲ and CuSbS۲ compounds are semiconductors with a band gap of about ۰.۸۱ eV and ۰.۶۲ eV respectively. A lack of negative frequencies in the phonon dispersion curves of these compounds shows the stability of the compounds. The static refractive indices of CuSbSe۲ compound are ۴.۳۸, ۳.۶۶ and ۳.۳۰ calculated within GGA, GGA+U and GGAmBJ+U approximations respectively and plasmon frequencies obtained from the peak of the loss function is occurred at energies around ۱۶eV.A trend of electrical conductivity behavior against temperature verify the semiconducting n

Keywords:

Density functional theory , Optical Properties , thermodynamic properties , semiconductor