Preparation And Characterization Of Cu/Li/Ag Doped ZnO Thin Films By Sol-Gel Method

ZnO is a multifunctional material with good photoelectric, gas sensitive, piezoelectric properties. And it has large energy band-gap and high exciton binding energy at room temperature and it has potential applications in transparent electrode, luminescent devices, solar cell, gas sensor et al. In the past decade, ZnO has aroused a lot of research attentions in many fields, such as physics, chemistry, material, electronic and etc.In this paper, the undoped, Cu-doped, Li-doped, Ag-doped and co-doped ZnO thin films were prepared on Si, ITO and glass substrates by Sol-Gel method. The effect of process conditions such as concentration of Zn+, doping concentrations, annealing temperatures et al on the structure, morphology, photoelectric characteristic and etc of the thin films were studied by X-ray diffraction (XRD), Scanning electron microscope (SEM), Transmission electron microscopy (TEM), UV-Vis photometer, Electrochemical workstation et al. The specific contents of the dissertation are as follows:At first, we investigated the effect with different concentrations of Zn2+on the structure, morphology, photoelectric characteristic of undoped ZnO thin films, it was found that the ZnO film had superior photoelectric qualities when the concentration of Zn2+in zinc sol. And then keeping the concentration of Zn2+, we had prepared Cu, Li, Ag single doped ZnO thin films with different concentrations respectively and studied the influence of process parameters such as doping concentrations, annealing temperatures et al on the photoelectric characteristic of ZnO thin films, it was found that when the doping concentration of Cu, Li, Ag was0.001at%,3at%,7at%respectively, the single doped ZnO thin films had good combination properties annealed at550℃in air, compared with undoped ZnO thin film, the conductivity of Cu, Li, Ag single doped ZnO thin film had been improved40,200,200times respectively and the transmittance was80%,95%,90%in visible respectively.Secondly, based on the single doped ZnO thin films, we had prepared Cu and Li co-doped, Ag and Li co-doped ZnO thin films, and investigated the effect of mole ratio between Cu and Li, Ag and Li on the combination properties of co-doped ZnO thin films. The result was that when the mole ratios of Cu and Li, Ag and Li, Li and Ag were all1:20, the co-doped ZnO thin films had better combination properties annealed at550℃in air. Compared with undoped ZnO thin film, the conductivity of Cu and Li, Ag and Li, Li and Ag co-doped ZnO thin films was improved6,150,300times respectively and the transmittance was85%,95%,90%in visible respectively. In addition, we also investigated the effect of different doped sources, substrates, thickness et al on the structure, morphology, photoelectric characteristic of the films, and the corresponding doped ZnO nano particles were also studied.