Stable electron field emission from PMMA-CNT matrices.

We have created PMMA-CNT matrices by embedding opened-tip vertically aligned multiwalled carbon nanotubes (VA-MWCNTs) with poly(methyl methacrylate) (PMMA). These PMMA-CNT matrices are excellent electron field emitters with an emission threshold field of 1.675 V/μm, more than 2-fold lower that that of the as-grown sample. In addition, the emission site density from these matrices is high, merely filling up the entire sample surface. Emission stability test at ∼1.35 mA/cm(2) was performed continuously for 40 h with no significant degradation. On the basis of our theoretical simulation and hypothetical modeling, we attribute these performances to the reduced screening effect and fewer Joule heatings due to the shorter effective transport distance of the electrons in MWCNTs.