Characterizations of fine-pitched carbon nanotube pixels for field emitter arrays

Fine-pitched carbon nanotube (CNT) pixels for field emitter arrays were patterned using a lift-off process. Compared with the conventional screen-printing method, this lift-off process provides a small feature size of 195 μm × 80 μm pixels in emitter arrays. The field emission properties of patterned pixels are highly dependent on surface morphology. The buried carbon nanotubes from the surface barely contribute to field emission in a low electric field range. By using a proper formulation of carbon nanotube slurry for emitters in the patterning layer, we were able to obtain carbon nanotube pixels in which most of carbon nanotubes protruded from the surface layer of patterns after a final heat treatment, to burn out the organic binders at 300°C. Their turn-on field was determined to be less than 2.2 V/μm and the current density was 3.2 mA/cm² at 3.7 V/μm. This lift-off process has the potential for use as an inexpensive patterning method for fine-pitched emitter array on a large substrate.