Direct imaging of intrinsic molecular orbitals using two-dimensional, epitaxially-grown, nanostructured graphene for study of single molecule and interactions

Abstract

Using epitaxially grown graphene on Ru(0001) as a buffer layer, the intrinsic molecular orbitals of perylene-3,4,9,10-tetracarboxylic dianhydride, pentacene, and C60 molecules were imaged by means of scanning tunneling microscope (STM). Combined with density functional theory calculations, our high resolution STM images of the molecules reveal that the graphene layer decouples the individual molecules electronically from the metallic substrate. Our results show that graphene-based moiré pattern can be used as a unique way to probe the intrinsic electronic structures of molecular adsorbates and their interactions.