Effects of Co and Cu dopants on the structural, optical, and electrical properties of ZnO nanocrystals

Kara I., Atilgan A., Serin T., Yildiz A.

Journal of Materials Science: Materials in Electronics, vol.28, no.8, pp.6088-6092, 2017 (SCI-Expanded) identifier


Co and Cu doped ZnO nanocrystals were successfully deposited by a sol-gel process. The structure of the samples was characterized by X-ray diffraction. The effects of the dopants on optical and electrical properties of ZnO were investigated by UV-Vis spectroscopy and electrical conductivity measurements, respectively. The band gap slightly decreased with dopants and decreasing grain size due to a deterioration of the crystalline structure. The refractive index of the films was estimated using transmittance spectra. Utilizing this data, porosity values of the films were also evaluated. Co-doped film was found to be more porous than Cu-doped film at the same doping level. Refractive indices of doped films were a little lower than that of undoped ZnO above 460 nm. The electrical conduction was controlled by grain boundaries and the electrical conductivity decreased with dopants due to increasing surface trap density.