Effect of K doping on CuPc: C{sub 60} heterojunctions

Journal Article · Thu Dec 01 04:00:00 EST 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3665711· OSTI ID:22036785

Cheng, Chiu-Ping; Chen, Wen-Yen ^[1]; Wei, Ching-Hsuan; Pi, Tun-Wen ^[2]

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1. Department of Electrophysics, National Chiayi University, Chiayi 60004, Taiwan (China)
2. National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China)

Here, the electronic properties of K-doped copper phthalocyanine (CuPc): C{sub 60} heterojunctions are studied via synchrotron-radiation photoemission. The K-doped heterointerfaces were obtained by means of C{sub 60} on K{sub 1.5}CuPc and CuPc on K{sub 3}C{sub 60}. The photoelectron spectra show that the potassium prefers to combine with C{sub 60}. At the C{sub 60}/K{sub 1.5}CuPc interface, the K diffuses and transfers negative charge into the C{sub 60} overlayer, while no strong chemical reaction could be found at the CuPc/K{sub 3}C{sub 60} interface. A significant shift of the vacuum level was observed in both cases, which was caused by the charge transfer for the C{sub 60}/K{sub 1.5}CuPc and by the induced density of interface states (IDIS) dipole for the CuPc/K{sub 3}C{sub 60}. The energy level diagrams show that using C{sub 60} adsorption on a K-doped CuPc film is good for the improvement of photovoltaic devices. However, the inverse process, that of CuPc on a K-doped C{sub 60}, is unfavorable for the photovoltaic effect.

• OSTI ID: 22036785
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 11 Vol. 110; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ADSORPTION
CHARGE EXCHANGE
CHEMICAL REACTIONS
COPPER COMPOUNDS
DIFFUSION
DOPED MATERIALS
ENERGY LEVELS
FULLERENES
HETEROJUNCTIONS
INTERFACES
LAYERS
PHOTOEMISSION
PHOTOVOLTAIC EFFECT
PHTHALOCYANINES
POTASSIUM
SYNCHROTRON RADIATION
THIN FILMS
X-RAY PHOTOELECTRON SPECTROSCOPY