The nano-structure of C-60 photopolymers has been investigated using in sit
u Fourier-Transform Infrared spectroscopy (FTIR), X-ray photoelectron spect
roscopy (XPS), and scanning tunneling microscopy (STM). The FTIR and XPS st
udies revealed that the C-60 photopolymer has a cross-linking via a [2+2] c
ycloaddition four-membered ring and formed a 2D rhombohedral structure when
the polymerization was saturated. Using STM, we have successfully observed
the direct real-space imaging of the C-60 dimers and trimers in a C-60 mon
olayer supported on a clean semiconductor surface.