Field emission performance of vertically aligned carbon nanotubes and their improved enhancement factors by the simple solution treatment

Abstract

In this study, the vertically aligned carbon nanotubes (VACNTs) are fabricated on substrate via a simply spraying chemical vapor deposition method. The relationship between the field emission performance and the aspect ratio of the VACNTs is systematically studied. The optimal growth conditions of the VACNTs with outstanding field emission performance are obtained. Meanwhile, the field emission properties of the VACNTs are further improved via a simple acetone-densification treatment. After the densification, the turn-on electric field and threshold electric field could decrease to 0.83 V/μm and 2.45 V/μm, respectively, and the field enhancement factor will increase to 26,588. In addition, the field emission current stability of the VACNTs is also strengthened. The improvement of field emission performance could be resulted from the reduction of field shielding effect after tip densification. The high current density and good stability demonstrate that the densified VACNTs are the promising and highly efficient field electron emitters.