高场发射性能碳纳米管薄膜的沉积与表征

利用电泳法将碳纳米管（CNTs）沉积在表面镀覆了50～150 nm Ti薄膜的Si基底表面,900℃真空退火后形成了具有良好场发射性能的Ti-CNTs薄膜阴极.利用X射线衍射和扫描电子显微镜对制备的Ti-CNTs薄膜进行了表征.结果表明,高温退火过程中,CNTs的C原子和基底表面的Ti原子发生化学反应,在CNTs与基底之间形成了导电性钛碳化物,明显改善了CNTs与基底之间的电导性和附着力等界面接触性能;与Si基底表面直接电泳沉积的CNTs薄膜相比,制备的Ti-CNTs薄膜的开启电场从1.31 V/μm降低到1.19 V/μm;当电场强度为2.50 V/μm时,Ti-CNTs薄膜的场发射电流密度可达13.91 mA/cm^2;制备的Ti-CNTs薄膜显示出改善的发射稳定性.

Deposition and Characterization of Carbon Nanotubes Film with Excellent Field Emission Properties

Ti-carbon nanotubes （CNTs） film with excellent field emission properties was prepared by electrophoretic deposition （EPD） of CNTs onto the titanium （Ti）-coated Si substrate, followed by vacuum annealing at high temperature （900℃ ）. The as-prepared Ti-CNTs film was characterized by XRD and SEM. The measurement results indicate that the carbon atoms of CNTs reacted with titanium to form conductive titanium carbide at the titanium-CNTs contact interface during annealing, which greatly improved the contact properties including electrical conductivity and adhesive strength between CNTs and the sub- strate. The field emission measurements show that, compared with that of EPD CNTs film on bare Si substrate, the turn-on field of Ti-CNTs film decreased from 1.31 V/μm to 1.19 V/μm; The emission current density of Ti-CNTs film reached 13.91 mA/cm^2 at the electric field of 2.50 V/μm. Besides, the Ti- CNTs film showed a more stable field emission at high applied electric field.