Study on structure of heat-treated fullerene nanowhiskers and their field electron emission characteristics

Single-crystalline fullerene nanowhiskers heated in a high vacuum at 2373K were characterized by scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The field electron emission from the heat-treated nanowhiskers was studied by field emission microscopy. The outer shape of the heat-treated nanowhiskers maintained its original morphology before heat treatment, that is, a straight shape with a uniform diameter along the long axis and a hexagonal cross section, whereas the inner structure was transformed from a single crystal of C60 to glassy carbon composed of crumpled graphitic layers. The field emission microscopy images of the heat-treated nanowhiskers, reflecting the atomic structures of the crumpled graphitic layers in the emitting region, exhibited striped patterns that are characteristic of graphite emitters. Copyright (c) 2011 John Wiley & Sons, Ltd.