基于C-W复合膜／无定形碳纳米岛的表面传导电子发射阴极

Electron Emission from Amorphous Carbon Nano-Islands Capped with C-W Films

介绍了基于C-W复合膜/无定形碳纳米岛的表面传导电子发射阴极,并对其制备工艺和发射性能进行讨论。利用低熔点纳米Bi岛作为掩模刻蚀得到无定形碳的纳米岛结构,在保留大岛形貌的同时,去除了一定量的小岛结构;同时在无定形碳中掺入少量的W原子,制作导电性极佳的C-W复合膜作为上层发射层,利于激活形成电子发射区域。通过对工艺参数的优化,得到了稳定、均匀的电子发射,电子发射率在阴阳极间距2mm、阳极电压为3 kV时达到0.9%,向器件实用化方向迈出了重要的一步。

An array of amorphous carbon nano-island, fabricated by oxygen plasma etching of the uniform carbon films with Bi-island as the mask, was coated with C-W films, deposited by magnetron co-sputtering. The impacts of sample preparation conditions, including the geometry of C island array, etching rate and W content, on the emission characteris- tics were evaluated. The microstructures and field emission characteristics of the field emitters were characterized with scanning electron microscopy, Raman spectroscopy and conventional probes. The results show that the cathode, fabricated under optimized conditions, generated stable and uniform electron emission. At a cathode-anode separation of 2 mm, and a bias voltage of 3 kV,the emission eitlciency was found to be 0.9%.