低成本制备的高稳定性碳纳米管复合阴极

Fabrication of High Stability Carbon Nanotube Composite Cathode with Low Cost

通过改变SiO2纳米溶胶与碳纳米管的比例,选择合适的表面活性剂解决SiO2表面湿润问题,使SiO2得以均匀包裹CNT。采用Sol-Gel工艺制备CNT/SiO2复合物阴极,使用TEM对复合物的形貌、结构进行表征,对其场发射性能与稳定性进行了研究,获得了高增强因子及低屏蔽效应的阴极。发射测试实验表明:复合物中SiO2/CNT含量为80%时,阴极具有高发射电流和较佳的场发射稳定性能。在场强为2V/mm时,发射电流为56mA/cm2,开启场为0.71V/mm,发射电流波动3h,波动<3%。该阴极发射电流高,稳定性良好,容易采用低成本的丝网工艺制备成各种不同尺寸FED阴极。

The new composites of carbon nanotube with silicon dioxide （SiO2） nanopartical for FED cathode was studied, which have high current density and stable emission property than pure CNT cathode. SiO2 nanopartical was fabricated by sol-gel process, which has significantly improved emission current density property and stable emission characterization of cathode, it has higher enhancement factor and less shield-effect by adjusting silicon nanopartical content. It was found that when about 20% CNT is optimum content, the current density at the electric field 2 V/μm is 56 mA/mm^2 , the turn-on field of the CNTs cathode was about 0.71 V/μm. The fluctuation of emission current is less than 3% for 3h. It is suitable for FED cathode with high current density due to good stability and low cost.