Low-temperature Solvothermal Growth Of ZnO Films And The Study On Performance

Recently, zinc oxide(Zn O) films have drawn widespread attention because of inexpensive and abundant material, non-toxic and excellent optoelectronic properties. For now, in numerous preparation methods of Zn O thin films, solvothermal technique is more and more be favored for its outstanding advantage, for example, easy preparation, low reaction temperature and controllable morphology, ect.In this paper, Zn O thin films were successfully grown on glass substrates with buffer layer using a solvothermal method. The precursors were zinc nitrate hexahydrate(Zn(NO3)2·6H2O), hexamethylene tetramine(C6H12N4) or urea(CO(NH2)2) and deionized water(H2O). Buffer layer material is made of zinc acetate dehydrate(Zn(CH3COO)2·2H2O), monoethanolamine(C2H7NO) and ethylene glycol monomethyl ether(HOCH2CH2OCH3). The influence of the growth time, the precursor concentration and temperature on morphology and optical properties of Zn O thin films was investigated and the best conditions were optimized. Meanwhile, in condition of hexamethylene tetramine, the effect of warm treatment of the buffer layer on morphology and properties of Zn O thin films was explored and proved that Zn O thin films were preparaed under the low temperature in a variety of flexible substrate. In order to reduce the temperature of system, replace Zn O buffer layer with organic buffer layer to get Zn O thin film. The structural, properties and morphologies of films were characterized by means of X-ray diffraction(XRD), atomic force microscopy(AFM), fluorescence spectrometer, UV-vis spectrophotometer transmission electron microscopy(TEM) and Scanning electron microscope(SEM).The results showed that all samples were Zn O films with exhibit wurtzite structure. Zn O films grown oriented along the c-axis were obtained under hexamethylene tetramine system. When growth time is 9 h, reaction temperature is 90 ℃and precursor concentration is 0.065 mol/L, preparation conditions is optimal and it has an better average transmittance in the visible range and the best crystallinity. At this point, Zn O is hexagonal nanorods and has the the biggest length to diameter ratio of 16. While Zn O thin films were successfully deposited on unannealed buffer layer and morphologies include nanosheet, rod like structure stacked by nanosheets, and so on. Zn O were obtained on flexible substrates and morphologies includ rods, pencil, brush pot-shaped and tubular. Zn O prepared in the urea system is the porous nanoflakes with large specific surface area. Photocatalytic degradation of methyl orange indicated that as the increase of growth temperature and precursor concentration, the degradation rate also decreases.