Optical bandgap and bowing parameter for Fe doped LaGaO3

TL;DR

This study investigates how Fe doping affects the optical bandgap and electronic structure of LaGaO3, revealing systematic bandgap reduction and mixed valence states of Fe, with implications for optoelectronic device design.

Contribution

It provides new insights into the bandgap tuning and valence states of Fe-doped LaGaO3 using experimental techniques, aiding the design of optoelectronic devices.

Findings

Optical bandgap decreases with Fe doping, saturating at 1.9 eV.

Bowing parameter for the solid solution is estimated at 3.8 eV.

Fe exists in mixed valence states, acting as electron dopant.

Abstract

The polycrystalline samples of LaGa1-xFexO3 have been prepared by standard solid state reaction route. The phase purity of the prepared samples is confirmed by powder xray diffraction experiments followed by Rietveld analysis. It has been observed that the variation of lattice parameters is governed by Vegards law. The optical band gap of these samples is estimated using diffuse reflectance analysis and it is observed that the optical gap systematically decreases with Fe doping from 3.62 eV and attains the saturation value of approximately 1.9 eV at x equal to 0.4. The value of the bowing parameter b for the prepared solid solution LaGa1-xFexO3 is estimated to be 3.8eV.The xray absorption near edge spectroscopy XANES suggests that the Fe is in mixed valence state in all prepared samples and these mixed states of Fe due to offstoichiometry acts like electron doping in LaGa1-xFexO3 and thereby results in the reduction in the effective band gap. Our results may be useful to design the LaGaO3based light emitting diodes and new generation of semiconductor photo-detectors.