Nanostructured Cu-doped ZnS polycrystalline thin films produced by a wet chemical route: the influences of Cu doping and film thickness on the structural, optical and electrical properties

作者：Goktas A^*; Aslan F; Tumbul A

来源：Journal of Sol-Gel Science and Technology, 2015, 75(1): 45-53.

DOI：10.1007/s10971-015-3674-8

• Wet chemical route
• Dip coating
• Cu-doped ZnS films
• Optical band gap
• Reactive index (n)
• Absorbtion coefficient (k)

A wet chemical route was successfully employed to synthesize nanostructured Cu-doped ZnS polycrystalline thin films with Cu-doping content varying from 0 to 20 %. X-ray diffraction measurements showed that both the undoped and the Cu-doped ZnS films possess a cubic crystal structure with (111) preferential orientation with an average crystallite size between 9 and 21 nm. Scanning electron microscope exhibited the surface of the nanostructured films to be homogeneous and dense, and the grains have good connectivity with each others. Using energy-dispersive X-ray studies, the presence of Cu in the Zn-S lattice was detected, which was in agreement with the concentration of precursors and the Cu ratios initially used for starting solutions. Optical studies showed a red shifting of absorption edge and a decrease in the optical band gap value from 3.60 to 3.32 eV as the Cu content and the film thickness increased. It was also observed that the increased Cu doping and film thickness resulted in a reduction in refractive index (n), with an increment of extinction coefficient (k) values in the visible range. However, by increasing the Cu dopant from 10 to 20 % Cu, the films exhibited a decrease in electrical resistivity with improvement in crystalline quality.

• 出版日期2015-7