Preparation and electron field emission of carbon nanowall by Cat-CVD

Carbon nanowall (CNW) films have been prepared by catalytic chemical vapor deposition using only CH4 gas. In the SEM images of the samples prepared at a substrate heating temperature, Ts, of 500 °C, the wall structures on the substrates were observed. In those prepared at Ts of 400 °C, however, the wall structure was not observed. The electron field emission from the CNW films was observed at small electric field. The wall width and height increased when the Raman intensity ratio, ID/IG, decreased. Then, the threshold electric field decreased. The smallest threshold electric field was 2.6 V/μm in this work.