Preparation And Research Of ZAO Thin Films On Flexible Substrate

In this paper, Al-doped zinc oxide(ZAO) films are firstly prepared on flexible substrates by direct current(DC) magnetron sputtering method, and then they would be tested by Adhesive tester, X-ray diffraction(XRD), scanning electron microscope(SEM), four-point probes and ultraviolet-visible spectrophotometer(UV). After that, we analysis the influence on the properties produced by three parameters including the argon pressure, the sputtering power and the sputtering time to obtain the best manufacturing technology. Under this technology, we finally compare the performance of ZAO film on polyimide(PI) and glass substrates.During the test, we can find that all ZAO films have a hexagonal structure and a preferred orientation perpendicular to the substrates along the c-axis. With the increase of argon pressure, the quality of films improves firstly and the optimal performance can be achieved when the argon pressure is 12 Pa. Under that pressure, films can obtain the biggest grain size and the best conductive properties. When comes to the sputtering power, it has great influence on the films of orientation perpendicular along the c-axis. If the sputtering power is too high or too low, the transmittance of 500 to 800 nm would be dropped. Beside, increasing sputtering time within a certain range can increase the thickness of the films and optimize the structure, the grain size and the conductive properties. Thus, the optimum conditions ZAO films for preparing high-performance conditions are as follows: the vacuum of 3103-′ Pa, the argon gas flow of 12 sccm, the argon pressure of 12 Pa, the sputtering power of 50 W, the sputtering time of 30 min.When preparing ZAO films on PI and glass substrates respectively using the best preparation conditions, due to the nature of PI, the lattice matching with films on PI substrates is so low that they have poorer structure and electrical properties comparing with films on glass substrates. But at the 550-800 nm band, the average absolute transmission rate of the ZAO film deposited on PI substrate was 96.5%, higher than 94.5% of the glass substrate.