钛基纳米金刚石涂层场发射阴极

Ti-based Nano-diamond Coating Field Emission Cathode

设计了一种新的金刚石场发射阴极工艺.用旋涂法在金属钛片上涂覆纳米金刚石涂层,经过适当条件的真空热处理,实现钛与金刚石之间的化学键合即欧姆接触,从而形成以金属钛为衬底,碳化钛键合层为过渡层,金刚石纳米颗粒为场发射体的场发射阴极.样品的阈值场强可达6.3 V/μm,场发射电流密度在21 V/μm场强下可达到60.7μA/cm2.提出了样品的结构模型,并分析了其电子输运方式.样品的Fowler-Nordheim曲线基本为一直线,根据经典场发射理论,可以证实其电子发射机制为场发射.观察到在获得稳定的场发射性能之前存在激发过程,并对其作了简单解释.

A new type of field emission cathode was devised. Nano-diamond powders were coated on the surface of titanium by spinning coating. After thermal treatment under proper condition in vacuum system, the bonding between diamond and substrate could be realized, and the cathode was formed with titanium as substrate,TiC as interlayer and nano-diamond powders as emitters. This kind of field emission cathode is adapted to large area preparation and batch production. The lowest threshold electric field of the samples as-prepared can be 6.3 V/μm, and the current density can reach to 60.7 μA/cm^2 at the field of 21 V/μm. The structure model of samples was supposed and the electron transmission mode during emission process was analyzed. According to conventional field emission theory, the emitted electrons mainly follow the field emission mechanism because of their approximately straight Fowler-Nordheim（F-N）plots. Before gained the stable field emission state, the excited process was observed and this phenomenon was explained.