Ultrasonic Atomizing Vapor Deposition Of Zno Films Prepared And Its Properties,

ZnO, which has a wurtzite structure, is a wide band gap, low dielectric constant and high chemical stability semiconductor. Because of its electrical, optical and piezoelectric properties, ZnO thin film has many potential applications. Traditionally, ZnO is used as acoustic 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 (25 emV), high-quality ZnO with a higher binding energy of 60 emV can be synthesized at much lower temperature, which promises strong photoluminescence from bound excitonic emission 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 were prepared by self-made Ultrasonic Spray Pyrolysis deposition technique. The structure and properties of the films were characterized by XRD, AFM, etc. The effects of growth parameters on the quality of ZnO films are discussed, such as solution concentration, substrate temperature, N₂ flow rate, the distance between the spray head and the substrate annealing temperature.As the results shown, the highly preferential orientation along c-axis of ZnO thin films could be prepared under optimized deposition condition:solution concentration 0.1 mol/L,deposition tempature 320℃, air flow rate 5.0 L/min, distance between spout and substrate 60 cm , reaction time 30min. The crystalline of the ZnO thin films become better annealed at 600℃in oxygen ambient. Al-doped ZnO thin films were also deposited on SiO₂/Si substrates by incorporating aluminum chloride (AlCl₃·6H₂O) in the zinc solution. The results showed that low doping concentration and high temperature are advantageous to grow c-axis oriented ZnO thin films.