Optimization of precursor based on optical, structural and magnetic properties of Cu-doped ZnO nanoparticles

Abstract

Cu doped ZnO nanoparticles were synthesized via co-precipitation method using different precursors like zinc chloride, zinc acetate and zinc nitrate. The crystallite structure, morphology and optical properties were discussed by X-ray diffraction, scanning electron microscopy and UV–visible photo-spectrometer for different precursors. The hexagonal structure was confirmed by X-ray diffraction. The calculated average crystallite size from XRD spectra was low for zinc chloride precursor (22.3 nm) and high for zinc nitrate precursor (26 nm). The strong and transparent behaviour in the visible region of the sample using zinc nitrate precursor is due to the existence of less defects and enhanced crystal size which leads to the industrial applications especially as transparent electrode. The reduction in strain and the better crystallinity effectively depress interstitial defects. The energy gap is varied between 3.65 and 3.75 eV, where zinc nitrate precursor has E_g = 3.65 eV (minimum) and zinc acetate precursor has E_g = 3.75 eV (maximum). The observed higher energy gap using zinc chloride precursor could be attributed to the poor crystallinity and also the formation of the new compound based on Cu and Zn. The low energy gap for zinc nitrate precursor can be attributed to the better crystallinity with increasing grain size. Change in luminescence intensity and magnetization were discussed based on the defects formation and structural parameters.