纳米金刚石阴极的均匀性及场发射特性研究

A study on nano-diamond cathode coating uniformity and field emission characteristic by electrophoresis

目的研究纳米金刚石阴极电泳工艺对场发射电流的均匀性、稳定性以及场发射特性的影响。方法用金相显微镜、扫描电子显微镜、X射线衍射和拉曼光谱观察了涂层的形貌和结构,经过高温真空退火后测试场发射性能,分析样品发光照片与涂层均匀性的关系,探讨热处理后场发射性能提高的机理。结果基底钛预处理要保持适当的平整度及光滑度,过度粗糙及过度光滑都不利于涂层的均匀性沉积。在同样的工艺条件下采用异丁醇溶剂配方后的金刚石涂层表面均匀性最好,场发射阈值电场最小,为5.5V/μm;当电场强度为15V/μm时,场发射电流密度为85μA/cm2,而且场发射电流的稳定性最好,发光效果最佳。结论异丁醇分散的电泳液制备的纳米金刚石阴极涂层均匀性最好,热处理后场发射性能最佳。

Aim To study the influence of nano-diamond cathode electeophoretic processes on the proportion and the stability of field emission current and light.Methods Observe the surface and structure of the coating by using metaloscope,microscopy,scanning electron microscopy（SEM）,X-ray diffraction（XRD） and Raman spectroscopy.Test the field emission characteristic after anneal.Analyze the relation between the samples′ light photos and the coating proportion;Discuss the mechanism of the improved field emission characteristic after anneal.Results The Titanium substrate pretreatment should be remain proper flatness and smoothness.Excessive crude and smoothness will do harm to the coating proportion deposition.Under the same condition the well-proportioned diamond coating could be by using isobutyl alcohol.It is the minimum threshold electric field emission,5.5 V/μm.the current density can reach to 85μA/cm2 at the field of 15V/μm.Moreover,the field emission current could be steady and best luminescence.Conclusion Nano-diamond cathode coating could be well-proportioned by using electrophoresis and isobutyl alcohol.Field emission characteristic could be best after anneal.