Synthesis and optical properties of Ni-doped zinc oxide nanoparticles for optoelectronic applications

Nanocrystalline undoped and nickel doped zinc oxide (Zn1-xNixO, x = 0.00, 0.01) powders are successfully synthesized by a simple and low-temperature auto-combustion method. The microstructural and optical absorption and emission properties of the as-prepared samples are obtained using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infra-red spectrometer (FTIR), UV-visible and photoluminescence (PL). The structure study confirms the formation of the hexagonal wurtzite ZnO without any secondary phase in the Ni-doped sample. The optical absorption measurements indicate the red shift in the absorption band edge upon nickel doping. The band gap energy decreases from 3.21 eV to 3.17 eV. The photoluminescence spectra of the as-prepared samples under a room temperature show strong ultraviolet (UV) and blue emission peaks. The PL emission research strongly reveals that Ni doping can effectively adjust the energy level which leads to a red shift at the emission peak in UV region.