Characterization of 2,9-Dihexylpentacene Films on Graphite (0001) by Metastable Atom Electron Spectroscopy and Ultraviolet Photoelectron Spectroscopy

Using metastable atom electron spectroscopy and ultra-violet photoelectron spectroscopy, the electronic structure and the molecular orientation of 2,9-dihexylpentacene are studied for two kinds of films prepared by vapor deposition onto a graphite (0001) substrate. It is found that the molecules lie flat in a monolayer of 0.4 nm thickness but stand up in a 16-nm film with the methyl ends of the chains exposed outside.