超声波焊接振幅对碳纳米管场发射阴极性能的影响

Influence of amplitude of ultrasonic welding on the performance of carbon nanotubes field emission cathode

通过高频超声波焊接来改善电泳后碳纳米管阴极的场发射性能,深入探讨了焊接振幅对碳纳米管焊接效果以及场发射性能的影响。结果表明,焊接振幅太小,碳纳米管无法与金属紧密接触;焊接振幅过大,在高超声能和剪切力的作用下碳纳米管阴极被破坏,场发射性能明显降低。选择20%~50%的焊接振幅,可有效焊接碳纳米管与基底,使两者之间形成可靠接触。开启电压随着振幅的加大而显著降低,从而构造出稳定的场发射阴极。

A high frequency ultrasonic welding was used to improve the performance of carbon nanotubes field emission cathode deposited by electrophoretic deposition.The effect of amplitude on the carbon nanotube ultrasonic welding and field emission characteristics were investigated.The results showed that carbon nanotubes could not be bonded to metal electrodes completely at low amplitude.While at high amplitude,carbon nanotubes were destructed due to the higher ultrasonic energy and shear force,and the performance of cathode was reduced evidently.Our work also revealed that at the amplitudes of 30%~50%,carbon nanotubes were welded firmly with metal to form a reliable contact.With the increase of amplitude,turn-on voltage decreased significantly and a stable field emission cathode was fabricated.