3D型冷阴极结构形态对场发射影响研究

通过在圆铜片上用导电银胶固定圆柱体和长方体形成3D型冷阴极,采用有限元分析软件ANSYS仿真分析了圆柱体和长方体上表面的电场分布,圆柱体直径为12.7 mm,长方体阴极上表面为正方形,边长为12.7 mm.两种阴极高度相同,采用化学气相沉积法(CVD),以酞菁铁(FePc)为催化剂,在圆柱体和长方体上表面合成了碳纳米管薄膜(CNTs),合成的碳纳米管形貌由场发射扫描电镜(FESEM)进行表征,采用二极管结构,以涂有荧光粉的ITO导电玻璃作为阳极,在真空室中真空度为2×10-4 Pa测设了两种3D型冷阴极的场发射特性,结果表明,随着两种阴极场强最大值比值增大,长方体阴极的场发射性能优于圆柱体阴极.

Effect of 3D Cold Cathode Structure on Field Emission

Cylinder and cuboid were fixed in circular copper by conductive silver glue to form 3D type cold cathode, surface electric field distribution of cylinder and cuboid was analyzed by finite element analysis software ANSYS.The cylinder diameter is 12.7 mm, the cuboid cathode surface is square and length is 12.7 mm.Two kinds of cathode have the same height.The carbon nanotube film (CNTs) were synthesized on the surface of cylinder and cuboid by chemical vapor deposition (CVD) and iron phthalocyanine (FePc) as catalyst.The morphology of carbon nanotubes were characterized by field emission scanning electron microscopy (FESEM).By using the diode structure and ITO conductive glass coated with phosphorpowder as anode, the field emission characteristics of two 3D type cold cathodes were measured in a vacuum chamber when the vacuum degree was 2×10-4 Pa.The results show that the field emission performance of the cuboid cathode is better than the cylinder cathode with the increase of the maximum ratio of the two cathode electric field intensity.