Tailoring the optical properties and the UV detection performance of sol-gel deposited ZnO nanostructured thin films via Cd and Na co-doping

Cd and Na co-doped ZnO nanostructured thin films with different doping concentrations were prepared using a sol-gel spin coating technique on glass substrates. The effect of doping with Cd and 1, 2 and 3 wt % Na on the structural, morphological, optical and UV detection properties of the nanostructured ZnO thin films was investigated. The grown co-doped nanostructured thin films exhibit wurtzite structure with preferential growth along the (002) plane. The change in the doping concentration was found to have a considerable effect on the grain size of the prepared films as well as their morphology. A variation in the band gap of the co-doped nanostructured thin films was also observed with changing the doping concentration. The band gap was found to vary in the range from 3.27 to 3.24 eV with increasing Na concentrations. The UV detection performance of the co-doped ZnO nanostructured thin films based UV detector was also investigated and found to strongly depend on the dopants concentrations with an obvious correlation with the variation in the films band gap. The findings of the current study show that a good control of the optical properties and the UV detection performance of the ZnO nanostructured thin films can be achieved through co-doing with Cd and Na with increased potential for their uses in high performance opto-electronic devices.