Comparative study of pure and chromium-doped nickel oxide nanoparticles synthesized by combustion synthesis for optoelectronic applications

Abstract

In the present research work, the incorporation of Chromium (Cr) doped nickel oxide (NiO) nanoparticles (NPs) were synthesized using the flash combustion process. The impact of Cr-doped NiO (Cr:NiO) NPs on the structural, optical, and dielectric properties was investigated in the research work. X-ray Diffraction (XRD) and FT-Raman (Fourier transform Raman) were also used to determine the phase of Cr: NiO NPs. The crystallite size decrease from 26.2 to 8.5 nm as the doping Cr concentration increased from 0.0 wt.% Cr to 5.0 wt.% Cr. The values of crystallite size and lattice strain were observed to vary with the changing concentrations of Cr: NiO nanoparticles (NPs), respectively. Scanning electron microscopy (FSEM) images revealed that Cr: NiO NPs have spherical shape particles of the prepared NPs. Diffuse reflectance spectroscopy (DRS) was employed to measure the optical band gaps of the prepared NPs using the Kubelka-Munk (K-M) function. The optical energy gaps for Cr:NiO decreased from 3.47 eV to 2.86 eV with an increase in the doping concentration of Cr in NiO. The dielectric properties have been investigated by incorporating Cr into the NiO lattice structure. The highest dielectric constant was observed for 7.5 wt% Cr loaded NiO NPs, which is almost two times that of pure NiO. The reduced crystallite size, enhanced band gap, and dielectric properties indicate the significance of the synthesized NPs in optoelectronic devices.