Effect of Li co-doping on highly oriented sol-gel Ce-doped ZnO thin films properties

Undoped, Ce-doped and Ce–Li co-doped ZnO thin films have been deposited onto glass substrates by sol–gel dip coating method. The effects of Ce–Li co-doping for 0.1 at.% Ce and 0–20 at.% Li on the structural,... [ view full abstract ]

Undoped, Ce-doped and Ce–Li co-doped ZnO thin films have been deposited onto glass substrates by sol–gel dip coating method. The effects of Ce–Li co-doping for 0.1 at.% Ce and 0–20 at.% Li on the structural, morphological and optical properties of the ZnO films were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), UV-Vis-NIR spectrophotometry and photoluminescence spectroscopy (PL). XRD analysis revealed that all the films were highly c-axis oriented and had a hexagonal wurtzite structure. AFM images showed that film morphology and surface roughness were influenced by Li doping concentration. UV-Vis-NIR measurements indicated that the film transmission decreases with increasing Li content and the optical band gap was dependent on the Li concentration. Room temperature PL spectra put into evidence that emission is significantly influenced by Li content. In particular, it was found that the visible emission intensity of the film with 20 at.% Li doping in 0.1 at.% Ce-doped ZnO is approximately 30 times greater than that of the undoped film.