Selective formation of thickness-controlled fullerene disks by vapor-solid process

Abstract

Thin C-60 disks were selectively prepared without any solvent using a vapor-solid process. A tube furnace with three separate heating zones was used. Controlling the substrate temperature and the vapor temperature made the selective formation of the thin C-60 disks possible. The temperature of the first and second zones for evaporation of C-60 was fixed at 650 degrees C, the temperature of the third zone at 500 degrees C, and the temperature of the substrate between 150 and 300 degrees C by water circulation through the sample stage. The thickness of the thin C-60 disks decreased as the substrate temperature increased in the range of 150-300 degrees C. This occurred because the growth rate of a crystal increases as the difference between the evaporation temperature and the substrate temperature (crystallization temperature) of the fullerene increases.