Adsorption structure of copper-phthalocyanine molecules on a Si(100)2x1 surface observed by scanning tunneling microscopy

Isolated copper-phthalocyanine (CuPc) molecules adsorbed on a Si(100)2 x 1 surface have been observed by scanning tunneling microscopy; (STM). The molecular images indicate three configurations which are dominated by the interaction between the aromatic rings of CuPc molecules and dangling bonds of the Si surface. We suggest that STM images reflect the molecular orbital formed by aromatic rings of CuPc and Si dangling bonds.