| Al-doped Zn O(AZO)thin films are widely used in various fields such as flat panel displays and thin film photovoltaics, not only due to its comparable electrical and optical properties with ITO thin films, but also its abundance in raw materials, low manufacture cost, high performance-price ratio, environmental-friendly nature and good environmental stability and convenience for later processing, etc. It is a tendency that AZO thin films will take the place of ITO thin films. In decades, the researchers from home and abroad have done a lot of work on preparation method and performance optimization. At the same time, they also had a great deal of achievements. The magnetron sputtering is the most commonly used and mature method because of its outstanding advantages of simple operation, stable process and evenly coating. However, AZO thin films are deposited under high temperature according to most reports about the magnetron sputtering method, namely heating the substrate during the deposition process or annealing treatment to the samples after the deposition process. So, this has greatly limited its application on the materials which can not tolerate high temperature such as flexible substrate and some sensitive photo resist materials.Given this, the study and research on the deposition of AZO thin films by magnetron sputtering at room temperature is conducted in this thesis. Al-doped Zn O(AZO)films were deposited by RF magnetron sputtering of Zn O target mixed with Al2O3(2 wt% Al2O3)on glass substrate at room temperature. This thesis has a systematic study about the influence of several parameters has to the properties of AZO films. I used the figures of merit to measure the photoelectric integrated performance. In the meanwhile, I proposed the way of the introduction of Si O2 thin film as a buffer layer and compared the properties of the samples with and without the buffer layer. The conclusions are as follows:(1) Under the conditions described in this thesis, the AZO films had a good crystallization. The grains in all of the samples showed a highly oriented(002) plane;(2) After comparing the performance of each sample, I got the best technical parameters of the preparation of AZO thin films: sputtering power 300 W, working pressure 0.25 Pa and deposition time 30 min. Under the best technical parameters, the films showed large grain size and structural integrity.The sheet resistance was 27.98?/□. The average transmittance in visible region was beyond 80%. The film showed a figure of merit of 4.32×10-3 ?-1;(3) The introduction of Si O2 thin film as the buffer layer can effectively improve electrical property of the AZO films. The sheet resistance of these samples had a significant decrease compared with the samples prepared directly on glass substrate. The insertion of buffer layer with a appropriate thickness can reduce the stress in the thin films and inhibit the Na+ in the glass substrate into the film. It could ensure the integrity of the lattice, improve the crystallization of the film and make grain size larger. When the buffer layer had a thickness of 30 nm, sheet resistance was 14.12?/□ while the average transmittance in visible region was 82%, which had a very tiny change compared with the samples prepared directly on glass substrate. The resistivity was 9.6×10-4 ?.cm and the figure of merit we calculated was 9.56×10-3 ?-1, better than these ITO thin films which were prepared at room temperature. |
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