有机溶剂高压气流法改善碳纳米管阴极场发射特性

Field emission property of CNT cathodes improved by post-treatment of high pressure airflow with organic solvent

针对丝网印刷碳纳米管阴极,提出有机溶剂高压气流法进行表面后处理,有效改善碳纳米管阴极场发射特性。利用表面轮廓仪、扫描电子显微镜及高分辨透射电子显微镜表征有机溶剂高压法处理前后CNT阴极表面形貌变化,并对处理前后CNT阴极进行场发射特性测试。结果表明,有机溶剂高压法处理后CNT阴极表面整洁无包覆,开启电场下降,场发射电流密度大幅度提升,发射点密度明显增大,均匀性提高,处理前后场增强因子比值为1∶2.8。

This paper presented a novel post-treatment method of high pressure airflow with organic solvent, which could effectively improve the field emission characteristics of screen-printed CNT cathodes. Notable changes in the surface morphologies of screen-printed CNT cathodes were investigated by stylus profiler,scanning electron microscope （SEM） and transmission electron microscope （TEM） as the function of treatment by high pressure airflow with organic solvent. The results showed the post-treated CNT cathodes hold lower turn-on electric field,higher field emission current density,more emission sites, and better uniformity than those of untreated ones. It was also found that the ratio of electric field enhancement factor for untreated and treated CNT cathodes was 1 to 2.8. And it was proved that the field emission properties had been improved evidently,for removal of residual materials covered on the surface of CNTs.