Enhancement of the field emission of carbon nanotubes straightened by application of argon ion irradiation

The field emission properties of carbon nanotubes (CNTs) were enhanced by argon ion irradiation. Argon irradiation treatment led to an enhancement in the emission properties of CNTs which showed a decrease in turn-on field and an increase in total emission current after the treatment. The irradiation treatment permanently straightened as-grown curly CNTs, and, as a result, the local electric field was increased, due to the increased aspect ratio and reduced mutual shield effect. In addition, increased defects, produced by the argon irradiation are likely to make their effective surfaces more active, thus emitting more electrons.