Photosensitive carbon nanotube paste based on acrylated single-walled carbon nanotubes

A novel photosensitive carbon nanotube (CNT) paste based on an acrylated single-walled carbon nanotube (ac-SWNT), a cross-linking agent, and a photoinitiator has been prepared. Unlike the conventional photosensitive CNT pastes reported to date, our photosensitive paste system does not use a polymeric binder for the photopolymerization following UV exposure because the ac-SWNT itself has cross-linkable groups. Therefore, the subsequent firing process can be performed at relatively low temperatures and the residue of the organic vehicle in the SWNT pattern is minimized after firing. The ac-SWNT was synthesized from the reaction between carboxylated SWNT (ca-SWNT) and methacryloyl chloride in the presence of base, and its structure was characterized by Fourier transform infrared, Raman, and X-ray photoelectron spectroscopy. After UV exposure and development with N,N-dimethyl formamide a pattern with a resolution of 8 mu m was obtained from the photosensitive CNT paste, which was then fired at 300 degrees C to give a clear SWNT pattern. When the photosensitive CNT paste was used for the fabrication of a cathode emitter for field emission displays, the CNT pattern emitted electrons under an applied electrical field with emission characteristics comparable with those obtained with screen-printing from conventional CNT pastes. Therefore, such a photosensitive paste for fabricating SWNT patterns can be used in the production of field-emission displays and in future device integration requiring carbon nanotubes, because it provides large-area patterning of SWNT with high stability and uniformity.