Cu-doped ZnO synthesis by ionothermal method: Morphology and optical properties

Abstract Zinc oxide (ZnO) and Cu-doped ZnO nanostructures having different morphologies such as nanorod, nanosheet and flower like have been synthesized via a one-step, eco-friendly ionothermal synthetic method at ambient pressure using [OMIM]Br and [C8DABCO]Br ionic liquids in terms of solvent and template. The dopant contents in the samples were 3%. The synthesized nanomaterials were examined by using scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–Visible absorption spectroscopy, and Z-scan technique. The results show that ILs and Cu2+ play on significant role on morphology of nanostructures. The average crystal size of ZnO was found to be in the range of 15.5–17 nm. Also doped in different ILs are effect on bandgap of products. The third order nonlinear absorption coefficient and refractive index were calculated and increased due to the enhancement of polarizability by the doping ions (Cu2+). Open and closed aperture of Z-scan method revealed two photon absorption and self-focusing (n2 > 0) effect in the samples. Third order nonlinear susceptibility of samples is in order of 10 − 7 ( c m 2 / W ) . As a result, Cu dopant of ZnO samples are more effective than their morphology in nonlinear coefficient results. The synthesized samples are proposed as a new-type nonlinear optical materials for optical applications.