纳米裂缝位置可控的表面传导电子发射薄膜

Controllable nano-scale gap formation in surface conduction-electron emitter

提出一种新型结构的表面传导电子发射导电薄膜,该导电薄膜在中间位置向内有凹陷,基于电形成过程中焦耳热引起薄膜龟裂的原理,会在凹陷附近诱导纳米级裂缝形成,控制纳米裂缝形成位置。分析了此结构导电薄膜对裂缝产生位置的影响及2种不同电形成方法对裂缝形貌的影响,测试了电子发射性能,得到了发射电流特性曲线和发光图像。实验结果表明,这种新型导电薄膜能一定程度上控制纳米裂缝的形成位置,有利于改进表面传导电子发射的均匀性,在阳极高压2.0kV、阴极板电子发射单元施加的器件电压14V时,新型结构导电薄膜实现了均匀发光,发射电流最大为18μA。

A conductive film with new structure for surface conduction electron emitter is proposed in this paper.Since the specific conductive film structure is narrower in the middle part,the joule heat in this region can be larger than that in the other region.This may lead to a thermal stress concentration in the middle region,and finally cause the nano-scale fissure to be generated easily from this position.With this new conductive film structure,the formation position of the nano-scale fissure can be controlled easily.The results indicate that the nano-scale gap position formed in the conductive film can be controlled to some extent.SCEs with the specific conductive film have better uniformity compared with the SCEs with the conventional conductive film structure.For an anode voltage of 2.0kV and a device voltage of 14 V,the emission current of the SCEs with the specific conductive film can reach 18μA.