Reasearch On The Fabrication Of UV Detector Based On Oxide Nanostructures

In this thesis, the traditional chemical vapor deposition (CVD) method was used to prepare gallium oxide (Ga2O3), tin oxide (SnO2), and zinc oxide (ZnO) nanostructures. And a new simple technology was introduced to construct the corresponding UV detectors. Their properties on UV detection were also discussed.The first chapter of this thesis is an introduction to nanotechnology, ultraviolet detector, and one-dimensional nanostructures. The introduction to nanotechnology includes mainly the development, the preparation and the applications of nanomaterials. The introduction to UV detector includes some detection technologies developed in recent years. The future research will be centered on the preparation of UV detector with small size and high sensitivity. The good properties of the nanomaterials have made them the best choice for UV detecting. The one-dimensional metal oxides are also discussed as materials applied widely in UV detection.The second chapter introduces the synthesis of gallium oxide (GaO3) nanowires and their application on solar-blind ultraviolet detection. Firstly, the chemical vapor deposition method was used to prepare gallium oxide nanowires. Then, the synthesized nanowires were characterized by X-ray diffraction (XRD). scanning electron microscope (SEM). transmission electron microscopy (TEM), and other instruments. The growth mechanism was also discussed based on the testing results. Thereafter, a new simple technique was used to fabricate the solar-blind ultraviolet detector based on Ga2O3 nanowires. The photoconductive properties were examined and the results showed that the fabricated detector had a high selectivity and a fast response time to254nm light. The corresponding mechanism was discussed finally.The third chapter introduces the synthesis of tin oxide (SnO2) nanowires and their application on middle ultraviolet detection. Firstly, the chemical vapor deposition method was used to prepare tin oxide nanowires. Then, the synthesized nanowires were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), and other instruments. The growth mechanism was still discussed based on the testing results. Thereafter, the above simple technique was also used to fabricate the middle ultraviolet detector based on SnO2nanowires. The photoconductive properties were examined and the results showed that the fabricated detector had a high selectivity and a fast response time to303nm light. The corresponding mechanism was discussed finally.The fourth chapter introduces the synthesis of tetrapod-shaped ZnO nanostructures and their application on the near ultraviolet detection. Firstly, tetrapod-shaped ZnO nanostructures were synthesized by the chemical vapor deposition method. Then, the synthesized nanowires were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), and other instruments. Thereafter, the similar technique was used to fabricate the flexible ultraviolet photodetector with Au/ZnO/Au structure on PET plate. The corresponding ultraviolet detecting properties were examined and the mechanism was also discussed. The results show that the flexible device based on the tetrapod ZnO nanostructures responds very well to ultraviolet (365nm).The fifth chapter is a summarization about the research work of this paper, from the material-synthesis to the detector-constructing, and their detecting properties. All in all, UV photodetection has drawn a great deal of attention in recent years due to a wide range of civil and military applications. We use the traditional CVD method to prepare Ga2O3, SnO2, and ZnO nanostructures. Then we present a new simple technique to construct the corresponding UV detectors.