ZnO纳米棒/CNTs复合阴极的制备及其场发射性能的研究

Improvement of Field Emission Properties of ZnO Nanorods Array with Spray-Coated Carbon Nanotubes

采用水热法和喷涂法制备ZnO纳米棒/CNTs复合材料,并测试其场发射性能。首先采用水热法在ITO电极基面生长ZnO纳米棒阵列,随后通过喷涂技术在ZnO纳米棒阵列表面沉积碳纳米管(CNTs)。使用扫描电子显微镜和X-射线衍射分别表征样品的结构和形貌特征。结果表明,经喷涂沉积的CNT薄膜均匀地包裹在ZnO纳米棒尖端。对该复合材料采用二极结构测试其场发射性能,通过测试结果发现,ZnO纳米棒/CNTs复合材料可明显改善ZnO纳米棒阵列及CNT薄膜的场发射性能,该复合材料具有低开启电场强度(约0.96V/μm),高场增强因子(9881)。因此,ZnO纳米棒/CNTs复合材料是最有前景的场发射阴极材料之一。

The ZnO nano-rods/carbon nano-tubes（CNTs）composite was synthesized by spray-coating of CNTs on ZnO nano-rods array,pre-deposited in hydrothermal method on the glass substrate coated with indium tin oxides（ITO）films.The influence of the synthesis conditions on the microstructures and field emission properties was investigated.The composite was characterized with X-ray diffraction（XRD）and scanning electron microscopy（SEM）.We found that the uniformly distributed ZnO nano-rods,500 nm in diameter,stand vertically,whereas the CNTs lie flat on the substrates.Uniformly wrapping the tips of ZnO nano-rods with the homogenously dispersed CNTs significantly improved the field emission characteristics of the ZnO arrays.For instance,its onset field and field enhancement factor increased up to 0.96V/μm and 9881,respectively.Possible mechanisms responsible for the property enhancement were also tentatively discussed.