Study Of ZnO Thin Films Prepared By Nebulized Vapor Deposition

Zinc Oxide is a material widely used in many areas. Traditionally, ZnO is used asacoustic wave devices (SAW), bulk acoustic devices (BAW), Gas sensors, varistors, transparent electrodes, and so on. In recent years, ZnO has gained more and more attention as a wide band semiconductor. Compared to GaN, which is one of the most successful wide-band semiconductor materials at present, ZnO is promising: high-quality ZnO with very low defect densities can be synthesized at much lower temperature than GaN; ZnO can emits light with shorter wavelength than blue light emission from GaN; ZnO has higher excitonic binding energy (~60meV for ZnO, 25meV for GaN), which promises strong photoluminescence from bound excitonic emissions at room temperature; meanwhile, homogeneous bulk ZnO is available.In this paper, the various growth techniques, applications, and the uptodate progresses in the research of ZnO are reviewed. Highly C-axis oriented ZnO thin films are synthesized by Nebulized vapor deposition technique. The structure and properties of the films are characterized by XRD, SEM, AFM, UV-Vis Absorption, and Hall effect measurement, etc. The effects of growth parameters on the quality of ZnO films are discussed, such as substrates, substrate temperature, and solution concentration.P-type zinc oxide thin films were also prepared on glass substrates by nebulized vapor deposition by the addition of ammonia in the zinc acetate solution. Hole concentration as high as 2.5X 1017cm~3 is achieved. In addition, a prottype device consists of Al/n-ZnO/p-Si structure heterojunction was fabricated. It is found that by applying a forward bias of about 6 volts in vacuum, S-type negative differencial resistance (NDR) phenomena were found in such structure, which is of potential application.