Structural and optoelectronic properties of three different phases of Zn2V2O7 compound under pressure: FP-LAPW approach

Abstract

The structural, electronic, and optical properties of the zinc pyrovanadate (Zn₂V₂O₇) under hydrostatic pressure are investigated using the first-principle calculations. The Kohn–Sham equations are solved by the full potential linearized augmented plane wave approach. We have chosen the Perdew-Burke-Ernzerhof generalized gradient approximation for calculation of the exchange-correlation potentials. By the structural optimization, it is found that α-Zn₂V₂O₇ has higher stability than β - and γ-Zn₂V₂O₇. Calculated density of states spectra show that the hydrostatic pressure has a considerable effect on the O-p, Zn-d and V-d states on the top of valence band. By increasing pressure, the band gap value increases from α to β phase, then decrease at γ phase. By pressure, the absorption spectra are shifted towards high energies as the blue shift. The metallic character of α and β− Zn₂V₂O₇ is observed at 5–10 eV. The plasmon energies increase from α to β phase, with pressure. There is a close agreement between the calculated absorption spectra and the experiment. The high plasmon energy and the wide absorption energy range makes this compound suitable for the optoelectronic devices.