Formation of C-N Nanofibers in High Isostatic Pressure Apparatus and Their Field Emission Properties

Carbon-nitrogen (CN) nanofibers have been formed in High Isostatic Pressure (HIP) apparatus in 1:1 nitrogen-argon gas mixture at 75 GPa using graphite electrical heater. Bamboo-like, beads-like, corrugated and spring-like nanofibers with the diameter of about 100-150 nm and the length over 10 μm have been found in a deposit with a low content of amorphous carbon. The nitrogen content up to 8.5% was found in fibers by EELS analysis. The CN nanofibers were printed on cathode plate and the diode-type flat vacuum lamp with 1 inch diagonal was assembled for the field emission study with the gap between anode and cathode varying in the range of 300-900 μm. The turn-on fields were about 1.3 V/μm, the current density was 0.05 mA/cm2 at 1.35 V/μm. The time reliability and light emission test were carried out for above 100 hours. We suggest that CN nanofibers can be applied to the high brightness flat lamp because of low turn-on field and time reliability.