Crystal growth of C₆₀ thin films on layered substrates

The process of the C₆₀ thin film crystal growth on layered materials such as MoS₂ and mica is studied in detail with a combination of atomic force microscopy (AFM) and reflection high-energy electron diffractometry, and is compared to that on alkali-halide (NaCl) substrates. AFM shows that a single crystal containing triangle-shaped grains of 1-2 μm size with a (111) surface terrace is grown on the MoS₂ substrate over a large area through a layer-by-layer process, while the grains on mica are 200-400 nm in size and distribute with some disorder in the orientation. The epitaxial characteristics of the C₆₀ crystal growth on these layered substrates are discussed in comparison with that on alkali-halides.