Interfacial electronic properties of the heterojunctions C{sub 60}/rubrene/Au and rubrene/C{sub 60}/Au
- Department of Electrophysics, National Chiayi University, 300 University Road, Chiayi 60004, Taiwan (China)
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China)
Using synchrotron-radiation photoemission, we have studied the electronic structures of rubrene:C{sub 60} heterojunctions on Au substrates. The photoelectron spectra show that the interfacial properties at the C{sub 60}/rubrene/Au and rubrene/C{sub 60}/Au interfaces are asymmetric and do not follow the commutation rule. In the C{sub 60}/rubrene case, a gap state appearing in the initial deposition stage results from negative charges transferred from rubrene to C{sub 60}, while in the inverse deposition process, no strong chemical reaction could be found. A significant shift of the vacuum level induced by alignment of the charge neutrality levels of the two materials was observed in both cases. Furthermore, the charge transfer strongly enhances the dipole potential of the C{sub 60}/rubrene interface. The energy level diagrams show that the C{sub 60}-on-rubrene process has a superior number of advantages in the photovoltaic applications.
- OSTI ID:
- 22089344
- Journal Information:
- Journal of Applied Physics, Vol. 112, Issue 2; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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