For producing Zno thin film on the ITO glasses at the cathode, we use the electrochemical method to proceed oxidation reduction. It forms Zn(OH)2 at the first, and dehydrates to form ZnO after heating. We use smaller voltage to grow ZnO seeds at the beginning .It can help ZnO to grow stably on the glasses. ZnO has many different characters, when we change solution temperature, contents of disperser(PVP) or the annealing temperature, so my work is to do some research on these factors and discovers how they affect the Zno thin films¡¦ structures ,conductivity, mobility, and the opticals. We found if we don¡¦t grow seeds on the glasses ,the ZnO doesn¡¦t grow well .It grows thicker at the center than the edge. And the disperser changes the morphology of ZnO .The diameter of ZnO particle became smaller. Different annealing temperature and environment also affect the crystallinity, roughness and the character of optical and electricity. We use every type of the ZnO thin films we did on the DSSC to research what is the factor that affects the efficiency.

Both zinc oxide rods and zinc hydroxide slices grown on gallium arsenide in the aqueous solution of zinc nitrate and hexamethylenetetramine were studied. Zinc hydroxide is responsible for the growth of slices. Hexamethylenetetramine-zinc nitrate organometallic complex acts as the nucleus for zinc oxide rods formation. Incorporating with appropriate concentration of nitric acid in the aqueous solution, zinc oxide rods can dominate the growth at a lower temperature.

Oxide semiconductors, especially ZnO, have been a subject of considerable research interest due to their interesting optoelectronic properties. Recent researches have shown that one-dimensional ZnO nanowires have characteristics of high stability, good luminescence efficiency, low critical voltage, high radiate current density and durability. In this study photoluminescence (PL) spectroscopy and Raman scattering spectroscopy were utilized to explore the optical properties of ZnO nanowires. The ZnO nanowires were grown on a-plane sapphire substrates by a simple vapor phase transport method without metal catalysts. Such a catalyst-free synthesis can avoid the metal remnants in the nanowires. Room temperature PL measurement showed that the intensity of ultraviolet (UV) luminescence increases as the average diameter of ZnO nanowires decreases. Such an observation is quite different from the reported PL data of nanowires grown with the use of catalysts. Moreover, an ¡§anomalous¡¨ redshift of the UV peak position with diminished wire diameter was observed. We attribute this redshift to the effects caused by the laser heating. The full-width at half maximum (FWHM) of the UV luminescence from the ZnO nanowires was found to decrease with better uniformities of wire distribution, alignment, and diameter. In addition, the ratio of UV to green emission integrated intensities becomes higher as the FWHM of the UV peak decreases. Thus the FWHM of the UV luminescence seems to be a measure of the uniformity and crystallinity (defects) of ZnO nanowires. Temperature-dependent PL and Varshni relation fitting results show the center position of UV luminescence is 3.29 eV for ZnO nanowires, and 3.24 eV for ZnO buffer layer structures. The Raman spectroscopy and SEM studies showed that the samples with randomly oriented nanowire structures exhibit the A1(LO) and E1(LO) vibrating modes.

In this thesis, the powder formation and thermal treament parameters for low temperature firing of zinc oxide(ZnO) based multi-layered varistors are studied. Vanadium oxide(V2O5) was used as electrical former, and manganese oxide(MnOx), coblt oxide(CoOx) and other additives were used as electrical modifiers. The object of this thesis is to investigate the effects of additives on the electrical characteristics of ZnO varistors. Meanwhile, the parameters of thermal treament process of raw materials on the effects of low temperature cofiring of ZnO varistors are also studied. As a result, we found that V2O5 can lower the sintering temperature of ZnO-based varistor as low as 900¢J. Forthuremore, prolonged sintering duration and reduced ZnO particle size might lower the sintering temperature futher to a given temperature which makes it possible to co-fire the ceramic body, inner electrodes and outer electrodes. The formulation of powder with added 0.3mol%Mn3O4, 0.5mol%CoO and 0.1mol%Bi2O3 can obtain a high £\value of 24 and leakage current of 2£gA. Besides, we also found that the thermal treament of powder can affect the shrinkage or diffusion of inner electrodes in multi-layered ZnO varistor shape dramastically. Without thermal treament or inproper thermal treament conditions will cause the inner electrode over-shrinkaged or even disppeared. According to the results of experiment, 350~400¢Jand a longger period (4 hours and above) will improve the phenomenon of over -shrinkaged.

In this study, epitaxial ZnO films were grown by chemical vapor deposition (CVD) on LAO(200) substrate. This dissertation is divided into two parts. In the first parts, the growth of ZnO films on various time was investigated. In the second part, the growth of ZnO films on various pressure was investigated. In the first parts of the dissertation, high <10-10> orientation ZnO films were grown. For a long time growth, the grown ZnO films on LiAlO2 substrate have good crystallinity, as revealed by XRD In the second parts, we discuss the difference of ZnO films by varying the growth pressure. It was found that both stripe-like ZnO(10-10) films and hexagonal ZnO(0002) grain existed at lower pressure(50~75 torr), as reveal by XRD and SEM. High <10-10> orientation ZnO films were grown at higher pressure. From cross-section TEM result, we did not find considerable dislocations in the ZnO films, and the ZnO/LiAlO2 interface is shown to be smooth and with the formation of the interlayers, which represents that ZnO and LiAlO2 have some reactions below the temperature of 650 ¢J. From the selected area diffraction (SAD) patterns, the orientation relationship between ZnO and LiAlO2 was determined as [11-20]ZnO//[001]LiAlO2¡B[0001]ZnO//[010]LiAlO2.

In this study, we prepare the zinc oxide one-dimensional nanostructures with aqueous solution on GaN substrate. The morphologies of nanotip, nanorod and nanotube are formed with different modulation and chemical solutions. The thermal annealing with N2O ambiance at 300 ¢XC for 1 hr increase the UV emission and decrease the defects. The limit of choosing the substrate to grow ZnO nanostructures is lattice mismatch between ZnO and substrate. The buffer layer is sputtered on substrate to remove the limit. The pattern of buffer layer also can be used for selective area growth. Nanotip structure with rough surface shows the obvious lotus effect and nanotube structure with more active site and more surface area shows the better photocatalysis efficiency than nanotip structure.

The mechanism for the room temperature magnetic coupling and electric conduction in oxide diluted magnetic semiconductors (DMS) has been studied simultaneously on the Co:ZnO thin film by utilization of the electric field effect. We find that the carriers are bound on a defect in a radius much larger than the bounded magnetic polaron (BMP) radius, and can move by the variable range hopping (VRH) over a relative small distance. Therefore, a concentric bounded model consisting of a concentric localization configuration with a limited carrier VRH capability was proposed. In this model, the carriers localized around defects couples strongly with the doped magnetic ions forming a BMP in the inner sphere and can only itinerate with no spin coherence in the outer shell. Carriers can hop either by spin-polarized or by spin-independent VRH directly between or not directly between adjacent inner spheres, respectively. This model can explain both the electric and magnetic properties of the oxide DMS, and depicts an evolution of electric and magnetic properties associated with defect concentration.

Abstract Information science and technology ( IT; Including computer and communication), Biotechnology (BT) and Nanotechnology (NT), are the three main technologies dominant in the 21st century. In nanotechnology, quantum size effects or surface effect (due to enhanced surface to volume ratio) can cause many new and interesting phenomena. In the literature there is also evidence that addition of small metal particles to semiconductors can enhance the optical properties of these semiconductor ¡Vnanoparticle hybrid systems. In this thesis, an electrochemical method is used to fabricate Au and ZnO nanoparticles. To characterize the samples we use various techniques like TEM (for the particle size and crystal structure), XRD (for structure, particle size analysis), Absorbance spectroscopy (for analyzing the optical properties of these systems), Photoluminescence (to study the mechanism of internal emission in the ZnO nanoparticles) On the theoretical part, some calculations based on the Drude model we computed and compared to the experimental absorbance spectrum of the samples.

In this thesis , we study the surface morphology of InN thin film grown on O-polar ZnO substrate by Macular Beam Epitaxy with varied N/In flow ratio. In addition, we also observe the difference to surface of InN between the substrate have been thermal annealed or not. We analysis the samples¡¦ surface morphology and lattice structures with many different ways, such as atomic force microscope, scanning electron microscope, reflection high energy electron diffraction,transmission electron microscope, X-ray diffraction analysis and transmission spectrum measurement. From the results of SEM and AFM,while the N/In ratio increased for the process of epitaxy, InN thin film¡¦s surface would become much smooth but accompany some pin holes on the surface which indicates that there exist the interaction between substrate and InN thin film. In the X-ray diffraction analysis, the greatest value of Full Width at Half Maximum (FWHM) we get is 94.44 (arcsec) to the (0002) surface of InN that confirm pretty high quality of InN thin film grown on O-polar ZnO substrate have been made. Furthermore, the band gap measured by transmission spectrum is wider for the N/In ratio increasing either which may be caused by the formation of InxNyOz.

This research is preparing a Nanostructure zinc oxide thin films by sol-gel methods, we use spin coating method to coat the gel on the substrate, and then put the substrate from 100¢XC -500¢XC for 10 min after each coating. We change the concentration of sol-gel¡Badd dispersing agents and change the temperature of heat treatment to confer structure and morphology of nanostructure zinc oxide thin film. Through the experimentation we can know when the concentration of sol-gel become low, the film properties of zinc oxide thin films will become bad. And the thickness of zinc oxide thin films will become thick with increasing the concentration of sol-gel.And adding appropriate dispersing agents will become different morphology of ZnO thin film surface, on the other side, when the different temperature of heat treatment, the nature of crystal¡Broughness of the surface and photoelectric character will change. Then we accede AmAc to sol-gel solution will dope n ion into the ZnO thin film, and the thin film with doping n ion has better electric characteristic than without doping. In the end, we Prepare ZnO thin film to apply as thin film transistor, we can make a p-type channel TFT successfully. TFT's critical voltage is -0.72V,carrier mobility is 0.29 cm2/Vs and On/Off ratio is 1.1E4.