Research Of Doped ZnO Nanoscale Films By Sol-gel Method

ZnO is a kind of semiconductor with the combination of group Ⅱ-Ⅵ. At room temperature, its energy gap is as high as3.37eV, and the energy for the transition of the exciton is60meV. Since this kind of material is really promising in the further use of many devices, people have performed many explorations in the aspects of preparation of the films, the combination of the material, the devices made by the films, and so on.By adding aluminum element in the film, the conductive and transparent properties of the film could be enhanced. By adding magnesium element in the film, the energy gap will be broaden and the transparency in the region of ultraviolet will be boosted. By doping donor element in the film, P-type semiconductor film will be achieved, and this is quite essential for the development of semiconductor materials with P-N junction. If more than one kind of elements are doped in the film, the film of multi-functions will be prepared, and this is quite essential for the development of multifunctional materials and composite materials.In this article, we mainly talk about ZnO films prepared by sol-gel method, and exam the optoelectronic properties.Which includes:(1) Dope aluminum element in ZnO films, and by comparing transparency and conductivity under different doping ratio and temperature, discuss the difference between films. Among the films prepared, the one doped with1.0%ratio under500℃shows best optoelectronic properties. It is noticeable most of the films reveal the transparency of more than90%. (2) Dope Mg element in the films and by changing the doping ratio from1.0%to3.0%, the transparency of the films change little while improvement of the conductivity of the films are quite apparent. Dope Mo element in the films and it turns out that the transparency differs greatly while the conductivity shows great performance. Dope Na element in the films and the films show quite high transparency in the visible region. At the same time, this kind of films shows a certain amount of transparency in the ultraviolet region. With the improvement of doping ratio, the conducting type changes into P-type.(3) Two kinds of co-doped films are prepared by sol-gel method. The films doped with Na and Mg reveal the transparency of over90%in the visible light region. Change the ratio of doped Na and Mg, and the energy gaps of the films change correspondingly. The properties of the films doped with Al and Mg are greatly decided by the doping ratio. With low doping ratio, the films show good properties. While with the increase of the doping ratio, the transparency and conductivity of the films decrease accordingly.