Structural, mechanical, electronic and optical properties of MgZnO3 perovskite: First-principles study

Abstract

This study examines the structural, mechanical, electronic, and optical properties of MgZnO3 perovskite using the first-principles calculation based on density functional theory (DFT). We perform the comparative study using four different exchange–correlation functionals–LDA:CA, GGA:PBE, GGA:PBEsol and mGGA:SCAN, and incorporate a Hubbard U-potential of 4.0 eV to address the electron-correlation effect of Zn-3d orbital. Further, we implement a hybrid functional–HSE06 for the band correction. From the assessment of structural optimization, tolerance factor, and formation and cohesive energies, we predict the stability of our system. The investigation of its structural properties shows that it exists in a cubic phase with 3.71-3.81 Å of lattice constant. An analysis of its mechanical properties predicts that it is a stable, rigid, ductile, and crystalline material with a metal-ionic bond. Based on the band structure analysis, MgZnO3 perovskite has an indirect band gap energy in the range of 0.92-1.77 eV along R-Γ high symmetric points, indicating a suitable material for photovoltaic and photocatalytic devices. We observe the dominant contribution of O-2p orbitals around the Fermi level from DOS/PDOS calculations. Moreover, the optical characterization of this perovskite has been found to indicate high values of refractive index, optical conductivity, and reflection coefficient in the infrared region, and absorption of radiation in the ultraviolet region, which suggests it as a potential material for optoelectronic devices.