两步化学沉积法制备ZnO薄膜及其场发射特性

在低温常压条件下,以ITO玻璃为衬底,采用电化学法与湿化学法结合的两步化学沉积法制备了团簇状ZnO薄膜。利用XRD,SEM分析了薄膜结构和表面形貌,并采用二极管结构在高真空条件下对薄膜进行了场发射性能测试。稳定发射后,开启电场为3.0 V/μm。当电场为5.8 V/μm时,电流密度为583.3 μA/cm²。研究表明:两步化学沉积法低温制备ZnO薄膜是可行的,且该薄膜具有良好的场发射性能。

The Preparation of ZnO Film by Two Step Chemical Deposition Method and Its Field Emission Properties

As the cathode electrode of field emitters, ZnO films were deposited under low-temperature and normal atmosphere conditions. To prepare the ZnO clustered rods, a ZnO film was firstly deposited on ITO glass substrates by electrodeposition method as an interlayer.Clustered ZnO rods were then grown on the ZnO films by wet chemical method. The morphology and structure were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). X-ray diffraction analysis showed that the ZnO rods are hexagonal wurtzite structure, and the c-axes of rods are mostly along the normal direction of substrate surface. It can be seen that there are a large number of flower-like clusters configuration consisting of many nanorods with diameters in the range of around 300 nm by scanning electron microscopy. This method was proved to be a repea-table, low-cost and high-yield route to synthesize ZnO nanocrystals. The field emission properties of ZnO films were measured with a parallel diode-type configuration in a vacuum chamber.The synthesized ZnO clustered films were used as the cathode, and the ITO glass sheet as the anode. The vacuum in the tested chamber is under 10-4 Pa. The field emission of ZnO films showed that:turn-on field of about 1.3 V/μm and emission current density up to about 909.1 μA/cm2 at a bias field of 5.1 V/μm for the first measurement. Over three times measurements, the field emission is getting stabile. The turn-on field is about 3.0 V/μm and emission current density is 583.3 μA/cm2 at the electric field of 5.8 V/μm. It was proved that it is possible to synthesize clustered nanostructure of ZnO films by two step chemical deposition method, and the prepared ZnO films have good field emission properties. It could be a field emission cathode with charming future.