Please use this identifier to cite or link to this item:
DC FieldValue
dc.titleEffect of molecule-substrate interaction on thin-film structures and moleculer orientation of pentance on silver and gold
dc.contributor.authorZheng, Y.
dc.contributor.authorQi, D.
dc.contributor.authorChandrasekhar, N.
dc.contributor.authorGao, X.
dc.contributor.authorTroadec, C.
dc.contributor.authorWee, A.T.S.
dc.identifier.citationZheng, Y., Qi, D., Chandrasekhar, N., Gao, X., Troadec, C., Wee, A.T.S. (2007-07-31). Effect of molecule-substrate interaction on thin-film structures and moleculer orientation of pentance on silver and gold. Langmuir 23 (16) : 8336-8342. ScholarBank@NUS Repository.
dc.description.abstractEvaporated pentacene thin films with thicknesses from several nm to 150 nm on gold and silver substrates have been studied by ultraviolet photoelectron spectroscopy (UPS), near-edge X-ray absorption fine structure (NEXAFS), scanning tunneling microscopy (STM), and atomic force microscopy (AFM). It was found that pentacene thin-film structures, particularly their molecular orientations, are strongly influenced by the metal substrates. UPS measurements revealed a distinct change in the valence band structures of pentacene on Au compared to those on Ag, which is attributed to the different packing between adjacent molecules. Using NEXAFS, we observed 74 ±5° and 46 ±5° molecular tilt angles on Ag and Au, respectively, for all measured thicknesses. We propose that pentacene molecules stand up on the surface and form the "thin-film phase" structure on Ag. On Au, pentacene films grow in domains with molecules either lying flat or standing up on the substrate. Such a mixture of two crystalline phases leads to an average tilt angle of 46° for the whole film and the change in valence band structures. STM and distance-voltage (z- V) spectroscopy studies confirm the existence of two crystalline phases on Au with different conducting properties. z-V spectra on the low conducting phase clearly indicate its nature as "thin-film phase". © 2007 American Chemical Society.
Appears in Collections:Staff Publications

Show simple item record
Files in This Item:
There are no files associated with this item.

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.