Doping effect investigation of Li-doped nanostructured ZnO thin films prepared by sol-gel process

摘要

In this work, we report the effects of Li doping concentration (5, 10 and 15 at.%) on structural, morphological, electrical and optical properties of Li doped ZnO films. We used X-ray diffraction (XRD), scanning electronic microscopy (SEM), Hall-Effect measurements, UV-Vis-NIR and photoluminescence (PL) spectroscopies. XRD patterns showed that the deposited films had a hexagonal-wurtzite crystal structure with preferred orientation along the c-axis. SEM micrographs indicated that grain dispersion in the films were homogeneous. Hall-effect measurements revealed that ZnO thin films doped with 5, 10 and 15 at.% of Li have p-type conduction. The UV-Vis-NIR spectroscopy analyses demonstrated that all thin films were highly transparent in the visible region and the optical transmittance was dependent on the Li doping content. Room temperature PL spectra put into evidence that all Li-doped ZnO thin films emitted a UV-blue light and the emission intensities were found to be affected by Li concentration.