Optimization Of Growth And Characterization Of ZnO Nanorod Arrays Via Hydrothermal Method

ZnO is a semiconductor material with a wide direct band gap and it is widely used. It hasexcellent photoelectric properties, piezoelectricity properties, pressure sensitive properties andgas sensitive properties. There are a lot of preparation methods. In this thesis, it discussesdetailed various preparation methods of ZnO, such as principles and the advantages ordisadvantages. The hydrothermal method is widely used, because it has the advantages ofsimple operation, economic and low pollution, and growth easy to be controlled.Well-aligned and regular morphology ideal ZnO nanorod arrays were synthesized on Sisubstrates via two steps low-temperature hydrothermal method, though optimizing theexperimental conditions such as the concentration of growth solution, reaction time andtemperature, the seed layer. In order to restrain the lattice mismatch and thermal mismatchbetween the substrate and the ZnO, the substrate need be disposed by before pulling theannealing process before hydrothermal reaction. It means growth a seed layer on the substratesurface, then growth thin film use the hydrothermal reaction. It was found that onlydisordered ZnO nanorod arrays on Si substrates were obtained though hydrothermalsynthesized straight. But well-aligned ZnO nanorod arrays were synthesized using highlyordered ZnO nanorod arrays as templates to guide the growth via a hydrothermal method.This shows that the highly ordered ZnO nanorod arrays pre-formed on the substrates played acritical role in dictating the further growth of the well-aligned ZnO nanorod arrays. In thisthesis, based on the optimized conditions, using the template to guide the growth it mean twostep hydrothermal method, a film was grown on the Si substrate with a seed layer. ZnOnanorod film with uniformly distributed and good orientation was also synthesized of theexperiment. The experiment also synthesis uniform distribution and oriented nanorod arrayfilm.The sample was mainly characterized by scanning electron microscope (SEM), filmthickness instrument, photoluminescence (PL) spectroscopy in the experiment. Optimizegrowth through comparison and analysis SEM images. Analysis the morphology andcrystalline quality or optical properties of the thin film, though SEM and PL spectroscopy.The results indicate that the samples are ZnO with six crystal structures, growth perpendicularto the substrate, good orientation, and distribution of uniform density. The average length ofnanorod is about7μm measured by film thickness instrument. The thin film own highly crystalline quality and good optical properties. At room temperature, the High crystallinequality is advantageous to lasing characteristics of ZnO. The photoelectric properties of thefilms are more superior, own more advantages for development in these areas, solar cell,optoelectronic devices, ultraviolet detector etc.