Investigation Of Preparation Process And Properties Of (Fe, Cu)-doped ZnO Films By Sol-Gel Spin-Coating Technique

ZnO is a II-VI semiconductor material with wide direct band gap of 3.37 eV and a large exciton binding energy of 60 meV. For its large binding energy,the exciton is stable even in the room temperature. So it is considered as a promising material for light-emitting devices and semiconductor lasers with low thresholds in the UV region.In recent years, the researches and developments of ZnO films have attracted great attention and interest from researchers and the industry. All above excellent properties and application of ZnO highly depend on the preparation of high quality ZnO films with low cost. Sol-Gel method is used to fabricate ZnO films with high quality in the thesis. The main job of this thesis is focused on the deposition of ZnO films on the quartz plate. X-ray diffraction (XRD), scanning electron microscopy(SEM), ultraviolet-visible spectrophotometer (UV-Vis), photolu-minescence (PL) were employed to analyse the effects of surface topograph and optical properties induced by the different densities of Fe and Cu doping. We also try to explain the emission mechanism of UV and visible light of ZnO films at room temperature in this thesis.In chapter one, a comprehensive introduction of ZnO material is presented including the structure and basic properties of ZnO, growth technologies, potential applications. At last, the significance and characteristic of this thesis is given.In chapter two, brief information of the Sol-Gel Technique is listed such as history, basic principle and methods of fabricating films via Sol-Gel Technique. In the end of this chapter, the mechanisms of the measurements applied in the whole process of investigation of ZnO films are also introduced.In chapter three, the influence of solvents on the properties of ZnO films such as structure, morphology and optical properties is given.2-methoxyethanol (EGME) is found to be a better solvent for a high quality of ZnO films.In chapter four and five, Pure and Fe and Cu doped ZnO thin films were fabricated on the glass substrates by sol-gel method. X-ray diffraction(XRD), scanning electron micros-copy (SEM), ultraviolet-visible spectrophotometer (UV-Vis), photolu-minescence (PL) were employed to analyse the effects of surface topograph and optical properties induced by the different densities of Fe and Cu doping.Finally, a summary of this dissertation and suggestions for further study are listed.