旋涂法制备纳米ZnO阴极涂层及场发射性能

Preparation and Field Emission Properties of Nano-ZnO Cathode Coatings by Spin Coating Method

采用水热法制备了烟花状的纳米氧化锌,用X射线衍射仪和扫描电子显微镜对样品的结构和形貌进行了表征与分析。然后通过旋涂技术将掺入不同质量的氧化锌沉积到镍衬底上,经过热处理后进行了形貌表征和场发射特性的测试。结果表明:制备的样品是六方纤锌矿结构的花状纳米晶,镍基片上沉积的纳米Zn O涂层具有突出的发射体尖端且分布较均匀;在一定范围内,电流密度随掺杂氧化锌粉末的增多而增大,开启场强逐渐下降。原因是随着Zn O的增加,有效地增强了涂层的电子输运能力,增加了有效发射体数目进而提高了场增强因子。最后,分析了涂层的场发射机制。

Fireworks-like ZnO was prepared by hydrothermal method. The structure and morphology of the sample were characterized respectively by X-ray diffraction and scanning electron microscopy,and then,different quality ZnO was deposited onto the Ni substrate by spin coating technique,the morphology and field emission characteristics were measured after heat treatment. The results indicate that the prepared sample is flower-like ZnO nanocrystals with a hexagonal wurtzite structure,ZnO coating deposited on Ni substrate is uniform and has prominent emitter tips,within a certain range,the current density increases with increasing of doped-ZnO powder,turn-on field decreased gradually. The reason is that with the increase of ZnO,the electron transport capacity of the coating is effectively enhanced,and the number of effective emitters is increased so that improves the field enhancement factor. Finally,the field emission mechanism of the coating is discussed.