激光烧蚀对碳纳米管薄膜场发射性能的影响

采用丝网印刷工艺制作了碳纳米管(CNTs)薄膜阴极.经适当能量激光烧蚀后，相互粘连的CNTs随表面粘附有机物的蒸发而分散开，管间隙增加、屏蔽效应减小，使得场发射性能大幅度提高，开启场强降低、场倍增因子β增大.Raman光谱分析表明，随激光能量增加，CNTs表面缺陷增多，成为新的场发射点，对其β增大的贡献加强.相对于两电极结构，三电极中平栅极结构场发射性能经激光烧蚀有更显著的改善.这说明激光烧蚀是提高CNTs场发射性能的有效方法. 关键词： 碳纳米管薄膜 场发射 激光烧蚀 Raman光谱

Ablating of carbon nanotube by laser beam and its effect on field emission performance

Carbon nanotubes (CNTs) cathodes have been made by using screen-printing. Conglutinated CNTs were separated after ablation by laser beam. The spacing between CNTs is increased， the screen effect is diminished. Experiment results show that the field emission properties of CNTs film are highly improved， the relevant turn-on voltage was reduced and the field enhancement factor β was enhanced. From Raman spectra of multi-wall CNT films treated by laser ablation， the defects on CNT surface were increased with increasing laser energy， and became new field emission dots. Compared with diode structure, the flat gate structure showed better field emission performance. So the laser ablation is an effective method that could enhance CNT field emission properties， and has value in the research of CNT cathode materials. At the same time， the flat gate structure has better prospects in the structure design of CNTs field emission flat display.