AVS 52nd International Symposium
    Electronic Materials and Processing Tuesday Sessions
       Session EM-TuP

Paper EM-TuP8
Scanning Tunneling Microscopy Study of Rubrene on Au(100) Substrate

Tuesday, November 1, 2005, 4:00 pm, Room Exhibit Hall C&D

Session: Electronic Materials and Processing Poster Session
Presenter: Y.S. Cho, CSNS, Seoul National University, Korea
Authors: Y.S. Cho, CSNS, Seoul National University, Korea
Y.J. Song, CSNS, Seoul National University, Korea
H.J. Yang, CSNS, Seoul National University, Korea
S.H. Kim, CSNS, Seoul National University, Korea
Y. Kuk, CSNS, Seoul National University, Korea
Correspondent: Click to Email
Rubrene has become a strong candidate for an organic thin film transistor (OTFT) because of its high mobility 8 cm@super 2@/Vs,@footnote 1@ and easy processing on various substrates, together with pentacene. It has been pointed out that interface states work as scattering centers and results in poorly reproduced potential barriers for various metal contacts in the transport measurement. In this work, we investigated the geometrical and electronic structures of a single rubrene molecule and up to 10-monolayer rubrene adsorbed on Au(100) surface with scanning tunneling microscopy and spectroscopy. In the geometry of metal-rubrene-metal transport measurement, the molecule is positioned as if it flat on the contact metal. This geometry can be achieved by adsorbing the molecule on a metal substrate. At low coverages, rubrene molecules grow as a single phase from step edges, showing step flow growth. They show well ordered growth pattern at high coverages. We will show the coverage dependence of the HOMO-LUMO gap states and possible implication to the transport measurement. @FootnoteText@ @footnote 1@Vikram C. Sundar et al., Science, 303, 1644 (2004).