Tailoring electronic and optical properties of LaAlO3 by Cu inclusion: a DFT study

Abstract

First principles calculations in the context of density functional theory (DFT) provides a platform to investigate the material’s properties in a way to explain the physics of solids. Electronic, structural, and optical properties for pure and Cu-doped LaAlO3 are investigated. The study reveals that the band structure of LaAlO3 after the inclusion of Cu at the La site is affected significantly. Due to the substitution of Cu, there is a decrease in the band gap from 3.02 eV to 2.95 eV. Furthermore, the partial density of states of LaAlO3 changes significantly after Cu doping, which has confirmed the doping effect on intrinsic LaAlO3. The p and d states play a vital role on top of the valence band. The range in which the top of a valence band lies is from 0 eV to –9 eV having a significant effect and it is because of Cu-d states. The optical properties of both pure and doped systems were analyzed. Redshift was observed as absorption edge shifted from 4.5 eV to 4.0 eV and even the refractive index reduces from 2.25 to 1.0, which means the Cu inclusion significantly play its role to tailor optical properties. Hence Cu-doping affects the properties of LaAlO3 and makes it a suitable candidate for use in different optical devices.