STM studies of the epitaxial growth of C60 molecules on Si(111)-7×7 surface

Abstract

The results of UHV-STM investigation of C60 at various adsorption sites on Si(111)-7×7 surface using MBE were presented. At room temperature, molecules prefer the faulted half unit cell to unfaulted half unit cell. Through controlling the annealing temperature and time, C60 molecules could directionally move towards step edges where the density of electronic dangling bonds is the highest. The measurement of diameter and height at each adsorption site shows different intensities of interaction between molecules and Si atoms. We also studied the multilayer growth process of C60 molecules on Si(111)-7×7 surface, and observed the local ordering of the first layer after annealing at 600℃, which shows the realization of the growth mode transformation from Stankski-Krastanov to Frank-van der Merwe mode.