| ZnO film is aⅡ-Ⅵdirect compound semiconductor with wide band gap energy of 3.37eV and a exciton binding energy 60meV at room temperature. High resistivity ZnO films with a single C-axis preferred orientation determines that it has good piezoelectric constants and electromechanical coupling coefficient, can be used for a variety of piezoelectric, pressure light, electro-acoustic, acousto-optic devices and surface-based gas sensor. Not doped ZnO thin films is not the performance, by doping different elements, they can be applied to gas probes, alarms which restore the acid gas, flammable gas, gas of CH family and so on. In addition, it Blu-ray modulation, low loss waveguides, liquid crystal display, photocatalysis, electronic cameras, heat-reflective windows and other areas of potential applications. ZnO thin film with its performance varied widely, and to highlight the advantages of low cost, and because of its diverse preparation process is simple and easy to doping, and in the silicon IC-compatible, is conducive to integration of modern components, represents the development of modern materials direction, is a kind of potential films used in high-tech fields and the wide field of civilian. Another P-type doping of ZnO is also a recent study of another hot and difficult issues.This paper introduces the latest domestic and international progress in ZnO thin films, and ZnO thin film structure and properties of the main growth methods and has done a more detailed explanationThis study was prepared by Sol-gel ZnO thin films to study the preparation process parameters, annealing temperature, transition and other factors on the structure of ZnO thin films, optical properties and other effects. The main contents are:Sol-gel Preparation of co-doped ZnO thin film with Ag-Al and Li-Al, discussed their preparation process on performance. Therefore, this study Ag and Al doped and Li and Al doped transparent conductive film after the ZnO structure and optical propertiesThe use of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), four probe, and UV-visible spectrophotometer (UVS) and other measurements of the optical and electrical properties of the samples were characterized. The results showed that:the preparation of ZnO:(Ag, Al), ZnO:(Li, Al) films are hexagonal wurtzite structure, with a high C-axis preferred orientation, surface even, dense crystal network formed by a number of films, the average visible light transmittance of films up to 70%, relative to pure ZnO films, the addition of doping ions on the light transmission rate will be enhanced role to play, but with Ag+, Li+ content increased, the film transmittance decreases, and the red shift occurred, and for doped with Al ions is weak, with the Al3+ content gradually increased, absorption edge blue shift occurred in the film transmittance maximum at a certain concentration, but then accompanied by an increase in the content of Al3+ stabilized or decline. ZnO:(Li, Al) thin film sheet resistance has been tested in the 20Ω/□or so. The addition of doping ions and the increase of coating layers will reduce the sheet resistance. On ZnO:(Li, Al) thin film energy spectrum analysis, we know that effective doping Al3+ Zn2+-bit alternative.Of ZnO:Ag, ZnO:Li thin films doped with Al3+ doped weak, coating layers, annealing temperature to optimize the process parameters obtained Ag-Al codoped ZnO thin films prepared by the optimum conditions: sol concentration 0.5 mol·1-1; Ag+ doping concentration 3%, Al3+ concentration of 0.5%; coating layers 15 layers; drying temperature 180℃; heat treatment temperature 500℃; treatment time of 30min; cooling rapidly cooled at room temperature. Li-Al codoped ZnO thin films prepared by the optimum conditions:sol concentration 0.5 mol·1-1; Li+ doping concentration of 2.5%, Al3+ concentration of 0.5%; coating layers 25 layers; drying temperature 180℃; heat treatment temperature 500℃; treatment time of 30min; cooling rapidly cooled at room temperature. |
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