The Study On Characteristics Of ZnO Thin Films And Al-doped Zinc Oxide (AZO) Thin Film Prepared By Magnetron Sputtering

Zinc oxide（ZnO）is an extremely important II-VI semiconductormaterial, ZnO has a hexagonal crystal structure and wide band-gap. Because of itsexcellent characteristics, it can be widely used in the electrochemical field, such as thetransparent electrode, solar cell and so on; and it is also used in the field of sensors, suchas gas sensors, surface acoustic wave devices, UV detectors and so on. As effectivealternatives of In2O3:Sn（ITO）material, AZO films is advantageous for its low resistivityand high transmittance in the visible region. Besides, AZO thin films have theadvantages of low price, abundant resources and chemical stability under the exposureto hydrogen plasma. At present, there are many methods for making AZO films.Compared with other methods, magnetron sputtering technique is considered to be oneof the important techniques for preparing AZO films for its high deposition rate anduniformity.In this dissertation, ZnO thin films and AZO thin films have been prepared bymagnetron sputtering on the glass substrate. The main contents and experimental resultsare as follows:Firstly, in this experiment, We use direct current(DC) magnetron sputteringpreparation ZnO thin films on the glass substrates, which are annealed at400℃. Thefilms obtained were characterized and analyzed by x-ray diffractometer (XRD),scanning electron microscope (SEM), ultraviolet-visible and infrared lightspectrophotometer. The experimental results show that the C-axis preferential growth ofthe films is obviously and the grain size becomes larger, increasing from19.80nm to25.19nm. The average transmittance in the visible wave range can be up to90%. Theoptical band gap increases slightly from3.28eV to3.30eV and UV peak becomessharply. The results show that higher quality films are obtained after annealing. The annealing process is beneficial to the regrowth of ZnO thin films.Secondly, ZnO/Al/ZnO/Al/ZnO/Al/ZnO thin films have been deposited bymagnetron sputtering on the glass substrate and annealed under different temperatures,XRD, SEM, ultraviolet-visible and infrared light spectrophotometer are used tocharacterize the structure and properties of the prepared samples. The experimentalresults show that Al-doped multi-layer films have similar crystal structure with ZnOthin films after annealing. Zn atoms are partially replaced by Al atoms in the ZnO lattice.When the annealing temperature is600℃, the results show that the C-axis preferentialgrowth of the film is more obviously and the grain size get the largest, reaching18.5nm.In the visible region, the transmittance of the AZO film exceeds93%after annealing at500℃, Especially in the range of520-580nm, it can be up to97%. There exists asignificant emission peak at the vicinity of390nm. The results show that the intrinsicdefect concentration of ZnO can be adjusted by our experimental method. Meanwhile,the method can improve the transmittance of the AZO film.