电泳沉积纳米金刚石涂层场发射阴极工艺研究

Study on the Process of Nano-diamond Coating Field Emission Cathode by Electro-Phoretic Deposition

采用电泳沉积(EPD)制备薄膜的方法,在金属钛片上均匀地涂覆纳米金刚石涂层,经真空热处理,制成场发射阴极。该文主要研究了不同的电泳液配方、电泳电压及电泳时间对涂层制备的影响。实验结果表明,粘度系数较大的电泳液及较低的电泳电压下适当延长电泳时间有利于改善涂层的均匀性和致密性;典型样品开启电场为5.5 V/μm,在20 V/μm场强下的电流密度达到169μA/cm^2。发光测试表明,发光点密度较大且均匀分布,发光稳定,亮度较高。用X-射线衍射(XRD)和扫描电子显微镜(SEM)对样品的成份及形貌进行了分析,结合其场发射测试结果,解释了样品性能的差异和变化。

The nano-diamond powders were coated on the surface of titanium by the electrophoretic deposition （EPD） and through the thermal treatment in the vacuum system, the cathode was formed. In the paper, the effect of the different electrophoretic liquor, different electrophoretic voltage and the electrophoretic time on the preparation of the coating has been studied. The electron transmitted mechanism was discussed. The experimental result showed that the uniformity and the compactness of the coating can be improved by using the eleetrophoretic liquor of big viscosity coefficient and lower electrophoretic voltage as well as time extension. The opening electric field of the typical samples can be 5.5 V/μm, and the current density can be up to 169 μA/cm^2 at the field density of 20 V/ μm. The luminescent testing showed that the luminescent point has big density and uniform distribution, the luminescence was stable and has high brightness. X-ray diffraction （XRD） and scanning electron microscopy （SEM） were employed to study the component and surface of the samples. The diversity of the performance of the samples was explained combining with the field emission properties.