钛基底的纳米金刚石掺混纳米碳管的场发射特性

在纳米金刚石场发射的基础上, 研究了纳米金刚石掺混纳米碳管的场发射特性。采用电泳沉积法形成了纳米金刚石与纳米碳管的复合涂层, 经热处理后制备出阴极样品, 然后进行微观表征, 再进行场发射特性测试与发光测试。结果表明, 与未掺混的纳米金刚石阴极样品相比, 复合涂层阴极样品的场发射开启电场明显减小, 场发射电流提高, 在较低的电场下阳极表面荧光粉就可以发光, 但发光不均匀, 出现了"边沿发光"的现象。分析了纳米金刚石掺混纳米碳管场发射性能提高的机理, 是由于纳米碳管掺入之后, 涂层的电子输运能力得到增强, 涂层中有效发射体的数目增加。最后, 解释了"边沿发光"现象的成因。

Field Emission Characteristics of CNTs Mixed Nano-diamond Deposited on Titanium Substrate

On the basis of field emission characteristics of nano-diamond, the field emission characteristics of diamond doped CNTs were studied. The composite coating of diamond and CNTs was formed using electrophoretic deposition, and the cathode samples were fabricated after heat treatment. The microstructure, field emission and luminescence performance of the samples were characterized. Compared with the undoped diamond cathode, the turn-on field of the composite coating cathode decreases obviously, the field emission current increases. The fluorescent powder on the anode surface can luminescent under lower electric field, but the luminescence is nonuniform and the phenomena of ‘edge luminescence’ occurs. The improvement of the field emission characteristics is due the enhancement of the electron transportation capacity of the composite coating and the increase of the effective emitter number. Finally, the reasons of ‘edge luminescence’ were explained.