Based-ZnO P-n Junction UV Photodetector

UV photodetector has the character of small volume, fast response, high sensitivity, low cost and so on, therefore, UV photodetector has very important application value in the civilian and military area. It has been attracted more and more attention. Because ZnO semiconductor has low growth temperature, electronic-included defects, threshold voltage, high photoconductivity, chemical stability, thermal stability and so on, the research of ZnO UV photodetector achieves rapid development. To obtain high property of ZnO UV photodetector, researchers design device from different aspects including material composition, material size, device structure. The work mainly aims at the aspect of device structure, which respectively designs and studies the perpendicular p-n junction UV photodetector and radial p-n junction UV photodetector. The concrete studies are included as follow:The work in the first part includes fabrication of NiO film via Magnetron Sputtering and fabrication of ZnO film through sol-gol technology. Novel NiO/ZnO film perpendicular p-n junction UV photodetector is fabricated using these two materials. Subsequently, we study the working principle of the device. At last, compared to ZnO film UV photodetector, electrical properties of NiO/ZnO film perpendicular p-n junction UV photodetector has decreased the dark current by an order of magnitude, the on/off ratio is increased an order of magnitude as the photocurrent is maitained, besides this the response speed is also accelerated.The second part includes fabrication of ZnO/CdS/CdTe core-shell nanowire arrays via chemical vaper deposition and electrochemical deposition. Radial p-n junction UV photodetector is designed making use of ZnO/CdS/CdTe core-shell nanowire arrays. Subsequently, working principle of the device is elaborated. At last, the experimental result showed that the responsed time is on the order of a hundered milliseconds.