Structural and optical properties of undoped and aluminium doped zinc oxide nanoparticles via precipitation method at low temperature

Zinc oxide (ZnO) and aluminium doped ZnO nanoparticles with grain size in the nanometer range have been successfully synthesized by alkali precipitation method. The grain size and morphology of nanoparticles have been investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The smallest size of about 25–30 nm with a spherical shape has been measured from 10 mol% aluminium doped ZnO. The optical band gap of undoped ZnO nanoparticles increases from 3.16 to 3.20 eV when increasing the aluminium concentration to 10 mol% into solution.