Theoretical investigation on the optoelectronic properties of ZrxSi1-xO2 tetragonal hypothetical alloys from zircon family

Herein, we present our numerical results of ZrxSi1-xO2 solid solutions (with x = 0–1) in order to predict new tetragonal hypothetical compounds from Zircon family. We have used the full-potential linearized augmented plane waves method based on the density functional theory DFT within GGA approximation as implemented in WIEN2k code to investigate the structural and optoelectronic properties of the named compounds. We have studied, in first step, the properties of the ZrSiO4 compound, where the obtained results are compared to several theoretical and experimental investigations. Secondly, we have predicted new hypothetical compounds for the Zircon family ZrSi3O8 and Zr3SiO8 which crystallize in I41/amd space group. Whatever, the chemical stability of the alloys under study was checked with both formation enthalpy and cohesive energy. Furthermore, the phonon dispersion results indicated this aspect also. The electronic properties reveals a strong p-d covalent hybridization between Zr and O. The Zr3SiO8 compound exhibits a large indirect band gap, while the ZrSi3O8 presents a direct band gap of 2.008 eV at Γ point. The optical quantities inspired from the dielectric function calculation are also calculated and discussed in details.