Exploring the role of hydrostatic pressure variation in tailoring essential physical properties of thermodynamically stable La2Zr2O7 pyrochlore oxide for high-performance photovoltaics: A first principles calculations

Abstract

This investigation explores the structural, molecular dynamics, electronic, elastic and mechanical, optical, phonon dispersion, and thermodynamic characteristics of La₂Zr₂O₇ under different hydrostatic pressures from 0 to 100 GPa with increments of 20 GPa through first-principles calculation by employing density functional theory. The result demonstrates a decrease in the band gap as pressure increases, maintaining the direct band gap and ensuring no disruption to the structural integrity of La₂Zr₂O₇. The dynamic stability has been evaluated using molecular dynamics and phonon dispersion simulations. The degree of localized electrons in different bands was confirmed by examining the pressure-induced total and partial density of states. The substance shows notable UV optical absorption, increasing with pressure and shifting to higher energies. La₂Zr₂O₇ is mechanically stable per the Born stability requirements. Furthermore, by using the quasi-harmonic Debye model in the region of 0–100 GPa pressure and 0–1000 K temperature, we may anticipate the compound's thermodynamic impacts on macroscopic characteristics, which will confirm its use in thermodynamic devices. The material's suitable properties under varying pressure suggest its potential applications in high-performance photovoltaic.