Properties And Preparation Of ZAO Thin Films Prepared By Sol-Gel Technique

At present, ZnO, new-style II-VI direct oxide semiconductor thin film with wideband gap energy and high carrier concentration, is widely applied in solar cell,transparent electrodes of flat panel display and some other areas. The optical bandgap of ZnO is3.3eV, and the exciton binding energy is60meV at room temperature.ZAO thin film is provided with comparable optical and electrical properties to otherkinds of oxide semiconductor thin films. In addition, the materials of ZAO arenon-toxic and adequate in nature, production procedure of ZAO thin films is simpleand low cost. Therefore, ZAO thin film has now become a hotspot as an alternative toITO film.Many kinds of preparations technology can be used in depositing ZAOtransparent conductive thin film, such as magnetron sputtering, chemical vapordeposition, sol-gel. The sol-gel method is divided into several methods ofspin-coating, dip coating, Spraying and Painting.In this paper, the ZAO transparent conductive thin films were deposited bysol-gel technique on common glass substrates. In the experiments of this paper, zincacetate was used as precursor; ethylene glycol monomethyl ether was used as solvent;ethanolamine was used as stabilizer; aluminum nitrate nonahydrate was used asdopant. After a series of process such as spin coating, drying, pre-treatment, heattreatment, the ZAO transparent conductive films were prepared.In this paper, the optical properties, crystal structure, surface morphology ofZAO transparent conductive films were characterized by ultraviolet-visible-nearinfrared spectrophotometer, four-probe resistance meter, X-ray diffraction andatomic force microscopy. Experimental results show that, ZAO thin film withstrongly preferred orientation of c-axis was the crystalline phase of hexagonalwurtzite, and the average optical transmittance of the films in visible spectrum regionis above90%, the lowest resistivity is10-4·cm, the film surface is Compact andsmooth. To achieve the thin films with the best qualities, Studying the interactionbetween a variety of factors, and making orthogonal experiments should be done.