Impact of Cu2+ doping on the structural and optical properties of LaFeO3 nanoparticles for optoelectronic applications

Abstract

We investigate the structural, linear and nonlinear optical properties of LaFe1-xCuxO3 (x = 0, 0.05, and 0.1) nanoparticles using XRD, SEM, and UV–visible spectroscopy techniques. The sol-gel technique was utilized to prepare the studied nanoparticles. The structural study shows that all compounds crystallize in the orthorhombic structure with the Pnma space group. The optical constants and parameters such as refractive index, extinction coefficient and dielectric constants were determined from the absorbance, transmission and reflectance. The refractive index (n) and extinction coefficient (k) were found to increase with increasing Cu content. As the Cu concentration increases from 0 to 0.1, the band gap energy (Eg) values were found to increase from 2.389 to 2.44 eV, while the Urbach energy (Eu) decreases from 0.42 eV to 0.312 eV. The single oscillator energy (E0) values were found to increase from 5.80 eV to 6.001 eV with increasing Cu content, as well as the dispersion energy (Ed) increases from 16.11 eV to 22.12 eV. For these samples, the nonlinear optical susceptibility (χ(3)) and nonlinear refractive index were determined to be between 1.3898 × 10−12 esu and 3.2906 × 10−12esu and 26.9436 × 10−12 - 57.2780 × 10−12esu respectively. These calculated parameters show also an increasing trend with Cu doping content.