CNTs-TiO_2复合薄膜的场发射及其在电离规中的应用

Field Emission and Their Application in Ionization Gauge of CNTs-TiO_2 Films

介绍一种制备碳纳米管(CNTs)薄膜的方法—擦涂法。利用这种方法制备了CNTs薄膜以及CNTs-TiO2复合薄膜,对其场发射性能进行了研究,发现CNTs+(7%～10%(质量比))TiO2复合薄膜的场发射性能与纯CNTs薄膜相比有较大改善,开启电场由2.5V/μm降低到1.3V/μm,阈值电场由4V/μm降低到3.1V/μm,场发射的均匀性与稳定性也有显著的提高。利用CNTs+7%TiO2薄膜样品作为电离真空规的冷阴极,实现了在2×10-2～3×10-5 Pa范围内的近似线性响应,灵敏度约为3.36Pa-1。这种电离真空规具有体积小、低能耗的特点。

We present a simple rubbing method for fabricating films of carbon nanotubes（CNTs） and CNTs-based composite materials.The CNT films and CNTs-TiO2 films are fabricated utilizing this method.The field emission properties of the films are systematically studied in comparison experiments.It is found that,with an optimum proportion（7%~10%）（wt.） of TiO2 nanoparticles mixed with the CNTs,the field emission properties of the composite films could be dramatically improved compared with simplex CNT films,in lowering turn-on field to 1.3 V/μm（CNT films： 2.5 V/μm） and threshold-field to 3.1 V/μm（CNT films： 4 V/μm）,increasing the field emission uniformity and stability.The applicability of CNTs-TiO2 films to cold electron sources for ionization gauges is investigated.The gauges exhibit good measurement of linearity in the pressure range of 2×10-2~3×10-5 Pa,and the sensitivity is about 3.36 Pa-1.The gauges also have the advantages of small volume and low power consumption.