The Fabrication Of ZnO Nanowire Arrays Via Hydrothermal Method And Field Emission Behaviors

The field emission display device is a new kind of flat panel display and its development is quickly. It has a broad application prospect owing to the combination of a number of advantages of the cathode-ray tube (CRT) and flat panel display. As wide bandgap oxide semiconductor material, ZnO has good chemical stability, oxidation resistance, morphology controllable, is a good cathode materials of field emission display device. Therefore, this subject was prepared the intrinsic ZnO nanowires array using hydrothermal method, and the research conducted the structures, morphology and the field emission performance. We also investigated the growth and field emission mechanisms of ZnO nanowire arrays. On this basis, in order to further improve the field emission properties, such as the lower open voltage and enhanced field emission factor, ZnO nanowires arrays were doped by Al, La, Cr, and we analyzed the influence of Al, La, Cr impurities on field emission properties of the samples. Main conclusions are as follows:(1) ZnO nanowire arrays have been synthesized on the Zn substrate deposited with the ZnO seed layer using sol-gel and low-temperature hydrothermal method and changing the different parameters of water process. The influence of the structures and morphology of samples using different technological parameters have been compared. The primary and secondary of the factors and the optimal hydrothermal process parameters of the preparation of ZnO nanowire arrays were obtained by range analysis. It is found out that at the optimal hydrothermal process parameters (Zn2+concentration:0.08 mol/L, [OH-]/[Zn2+]:20, reaction temperature:100?, reaction time:4h), the turn-on field and field emission factor of uniform ZnO nanowire arrays obtained are found to be approximately 1.60V/?m and 10835, and the 100?A of emission current with a degradation of 6% was measured after 30 hour.(2) At the optimal process parameters, Al:4.5% doped ZnO nanowire arrays were prepared. Comparing with the pure ZnO sample, Al:4.5% doped ZnO nanowire arrays exhibited the better field emission performance. After the preliminary exploration of field emission properties of Al doped ZnO nanowires array, we introduced the different concentrations of Al doping and the Al:5% doped and undoped of seed layer, have prepared the Al doped ZnO nanowire arrays of based on ZnO seed layer and Al doped ZnO nanowire arrays of based on Al-ZnO seed layer with the different doping concentration, and analyzed their field emission performances. The research showed that these two types of Al doped ZnO nanowire arrays in the 7% of Al doped theory concentration, had the lower open voltage and higher field enhancement factor. Comparing the two types of 7% of Al doped ZnO nanowire arrays, Al doped ZnO nanowire arrays of based on ZnO seed layer with the open voltage of 1.03 V/?m and field enhancement factor for 20658 had a good field emission performance.(3) In order to the results analysis of Al doped ZnO nanowire arrays for reference, La doped and Cr doped ZnO nanowire arrays were respectively synthesized and its field emission performances were analyzed. The results showed that the La:5% doped and Cr:7% doped obviously improved the field emission properties of ZnO nanowires array, and the turn-on fields of them were approximately 1.83V/?m and 2.35V/?m and the field emission factors of them were approximately 9208 and 5600.