Preparation Of ZnO Based UV Sensor And Analysis Of Its Electron Micromechanism

As an important short-wave photoelectric material ZnO has won great regards and perspective.The thesis explored ZnO based photoconductive UV sensor's performance by Sol-Gel and reactional magnetron sputtering method and seek the best technological parameters; analyzed the mechanism of photoconductive senor and the factors which impact the capability; finally, analyzed the change of the band structure in the electrons'micromechanism perspective.Fast Rapid photo-response and high sensitivity MSM structured UV sensor based on ZnO films were prepared by Sol-gel method. Besides, the stability was improved evidently by encapsulating an insulative pastern. Experiments were arranged according to the orthogonal experiment design. After analyzing effects of experiments, the optimized parameters were obtained: stirring time 2. Oh; rotate velocity 4000rpm; coated layers 3; annealing temperature 500℃; annealing time 2. 5h; drying temperature 200℃. The ascending time and descending time of photo response were 5s and 3s respectively under the UV light of 0. 85mw/cm at the bias of 10v. the resistance show decaying exponential with the UV intensity increasing.ZnO films were prepared by reactional magnetron sputtering method. Non-ohmic contact was found in the both annealed and non-annealed samples, and the non-annealed sample show faster response capability and higher sensitivity. Finally, target sintering flow parametres was researched and obtained right target.By using semi-conductor theory mechanism of the sensor was explained. Point defects and trap's effect on the performance was analyzed.Using first-principles ultrasoft pseudopotential method based on density-functional theory in the generalized gradient approximation we investigated the band structure of wurtzite ZnO,Zn₉O₇,Zn₈MgO₇ and analyzed the change of the three band structures from electrons' micromechanism. All the calculation were progressed in the MS. CASETP software.