D.A. Olyanich

Molecular simulations of C60 self-assembly on metal-adsorbed Si(111) surfaces

The authors have proposed a simulation procedure for the evaluation of energetics of C60 islands on crystalline surfaces that allows questions relating to shape, size, and orientation of the islands to be addressed. Simulation consists of placing a patch of close-packed C60 array of a given shape and size on a surface potential relief and finding energy minima by variation of island position and orientation. Upon appropriate adjustment of the surface potential relief, simulations reproduce well all the main results of the scanning tunneling microscopy observations. For C60 islands forming on In-adsorbed Si(111)3×3-Au and pristine Si(111)3×3-Ag surfaces, the optimal surface relief shows up as a periodic array of cosine-shaped peaks. The proposed approach provides a hint for understanding the driving mechanisms of C60 self-assembly, and, in principle, it can be applied to other adsorbate-substrate systems.