Carbon-nanotube cathode modified by femtosecond laser ablation

Femtosecond laser ablation of carbon nanotube (CNT) cathode was demonstrated in the laser fluence range of 0.05-2 J/cm². It was shown that the CNT ablated by femtosecond laser were aligned perpendicular to the cathode surface. The emission characteristics of the CNT cathode were measured using a diode system. The modified CNT cathode had a turn-on field of 1.8 V/μm, which was approximately half that of the original CNT cathode. As the laser fluence decreased, the turn-on field also decreased.