Interfacial electronic properties of the heterojunctions C{sub 60}/rubrene/Au and rubrene/C{sub 60}/Au

Journal Article · Sun Jul 15 04:00:00 EDT 2012 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4739720· OSTI ID:22089344

Cheng, Chiu-Ping; Chan, Yi-Wei; Hsueh, Chih-Feng ^[1]; Pi, Tun-Wen ^[2]

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1. Department of Electrophysics, National Chiayi University, 300 University Road, Chiayi 60004, Taiwan (China)
2. 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, Journal Name: Journal of Applied Physics Journal Issue: 2 Vol. 112; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ASYMMETRY
CHARGE EXCHANGE
DEPOSITION
ELECTRONIC STRUCTURE
ENERGY LEVELS
FULLERENES
GOLD
HETEROJUNCTIONS
INTERFACES
ORGANIC COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PHOTOEMISSION
PHOTOVOLTAIC EFFECT
SUBSTRATES
SYNCHROTRON RADIATION