Catalyst-free Growth And Optical Properties Of ZnO Nanorod Arrays On Al-doped ZnO Transparent Conductive Film

Zinc oxide is a direct bandgap, wide bandgap semiconductor material. One-dimensional ZnO nanostructure materials, because of their unique electronic transportation characteristics, surface effect and the optical properties, have been widely applied in various fields, such as light emitting diode, lasers, photodetectors, sensors, field effect transistors, and solar cells. There are a lot of research resports about the preparation and properties of ZnO nanostructures, but there are only few research reports about catalyst-free growth ZnO nanorod arrays on the transparent conductive film. Therefore, in this dissertation, we focus on catalyst-free growth and properties of ZnO nanorod arrays on the Al-doped ZnO transparent conductive film. The effect of the direction of substrate and growth duration on morphologies and optical properties of ZnO nanorod arrays has been investigated. The main contents are arranged as follows.Firstly, a large amount of high density ZnO nanorods had been synthesized on Al-doped ZnO (AZO) film, which was deposited on quartz substrates by magnetron sputtering by thermally evaporating Zn powder without using any metal catalysts. The AZO films were intentionally positioned in two directions of face and back to the zinc source. The results showed that the ZnO nanorods on the substrates with different directions have similar morphology, structure, and different photoluminescence spectra.Secondly, ZnO nanorod arrays (NRAs) on transparent conductive oxide (TCO) films had been grown by a solution-free, catalyst-free, vapor phase synthesis method at600℃. TCO films, Al-doped ZnO films, were deposited on quartz substrates by magnetron sputtering. The growth duration were changed from3min to12min. The results show that the electrical performance of the TCO films does not degrade after the growth of NRAs. As the growth duration increases from3min to8min, the oxygen vacancies and diffuse transmittance of the samples decrease, while the crystallinity, aspect ratio, near-band-edge emission, and total transmittance enhance. ZnO NRs self-attraction in the sample with9min growth duration has been observed, and two possible NRs self-attraction models are proposed. NRs in the sample with12min growth duration are disorder, which has the largest diffuse transmittance and the relatively strong deep-level emission. The sample with8min growth duration has the density about75um-2, diameter about26nm, and length about500nm, which can be used in a hybrid solar cell.Finally, copper oxide films were deposited on quartz substrates by radio frequency magnetron sputtering and the substrate temperature was changed from30v to300℃The effect of substrate temperature on the crystal structure and the optical properties of the films was investigated. Experimental results showed that the intensity of copper oxides diffraction peak increases, the sheet resistance decreases, and the refractive index increases with the increase of substrate temperature.