Unveiling the influence of dopants on structural, defect chemistry, morphological and optical characteristics of NiO nanostructures

Abstract

In this paper, undoped and doped (Fe, Co, and Fe-Co) nickel oxide (NiO) nanostructures have been synthesized using the co-precipitation method. Prepared samples were characterized for the structural, compositional, morphological, and optical properties using X-ray diffraction, scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS), UV-visible spectroscopy, and photoluminescence spectroscopy. Structural analysis confirmed the single cubic phase formation of undoped and doped samples. Defect chemistry showed that Fe-Co co-doped NiO possesses a lower density of defects than other samples. SEM results revealed the aggregation of particles. EDS results confirmed the presence of Ni, O, Fe and Co in the respective undoped and doped samples. Optical analysis revealed the band edge shifts with incorporation of dopants in the NiO crystal lattice confirmed the variation of band gap energy. Emission peaks were observed in the UV and visible region. Incorporation of dopants in the crystal lattice cause the variation of emission centres. Surface oxygen vacancies and imperfections significantly impact the emission characteristics of NiO. Variable spectral response of NiO with dopant incorporation has potential for optoelectronic applications.