Enhancement of field emission of CNTs array by CO2-assisted chemical vapor deposition.

We present a new process to get in-situ-growth carbon nanotubes (CNTs) array device with good FE properties by CO2-assisted thermal chemical vapor deposition (CVD). Field Emission measurement shows that introducing CO2 into CNTs growth system leads to a significant enhancement in the emission properties, both the turn-on field and threshold field decrease. Raman, SEM and TEM investigation results showed that in this CO2-assisted thermal CVD, CO2 can remove amorphous carbon during CNTs growth process, and at the same time, it also creates more defects on the CNTs wall. Both can enhance FE properties of the CNTs at suitable CO2 concentrations.