Field Emission from Conducting Polymer/Single-Walled Carbon Nanotube Composite Prepared by AC Coupled Electrophoresis

Abstract

The field emission properties of a carboxylic-acid-terminated single-walled carbon nanotube (SWNT–COOH)/conducting polymer [poly(3-octylthiophene), P3OT] composite film prepared by ac-coupled electrophoresis have been investigated. It was found that positively charged SWNT–COOH/P3OT colloids were selectively deposited onto an indium tin oxide (ITO) electrode, and the spatial resolution of about 1 µm was successfully obtained when ITO was coated selectively with partially fluorinated polyimide (FPI). The field emission properties of the composites were improved markedly for an amplitude of ac voltage and a frequency of higher than 100 V and 10 kHz, respectively. The emission properties were also improved for the film deposited on patterned electrodes probably owing to the vertical alignment of CNTs on the etched side of the FPI film, which contributes to a low turn-on field of 1.2 V/µm and a high field enhancement factor of 4300.