Cesium doping at C{sub 60}/rubrene heterointerfaces for improving the performance of organic light- and current-generating devices

Journal Article · Wed Jan 07 04:00:00 EST 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4905547· OSTI ID:22399237

Cheng, Chiu-Ping; Lu, Meng-Han; Chu, Yu-Ya ^[1]; Wei, Ching-Hsuan ^[2]; Pi, Tun-Wen ^[3]

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1. Department of Electrophysics, National Chiayi University, Chiayi 60004, Taiwan (China)
2. Department of Material Science, National Chiao-Tung University, Hsinchu 30076, Taiwan (China)
3. National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China)

This study examined the effect of adding cesium (Cs) at C{sub 60}/rubrene heterointerfaces by using synchrotron-radiation photoelectron spectroscopy. A C{sub 60}/rubrene heterostructure is the basis of a novel organic dual device found to facilitate efficient integration of both electroluminescent and photovoltaic functions. With Cs doping, the interfacial dipole potential was considerably enlarged, as was the separation between the lowest unoccupied molecular orbital of C{sub 60} and the highest occupied molecular orbital of rubrene. However, the energy-level diagram indicated that a high Cs concentration prevents the formation of photoexcitons. By contrast, adding a small amount of Cs can effectively improve the efficiency of light- and current-generating devices. In particular, the deficiency of the dopants at the heterointerface may benefit the survival of photoexcitons.

• OSTI ID: 22399237
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 1 Vol. 117; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CESIUM
CONCENTRATION RATIO
DIPOLES
DOPED MATERIALS
ELECTROLUMINESCENCE
ENERGY LEVELS
EXCITONS
FULLERENES
HETEROJUNCTIONS
INTERFACES
MOLECULAR ORBITAL METHOD
PERFORMANCE
PHOTOELECTRON SPECTROSCOPY
PHOTOVOLTAIC EFFECT
POTENTIALS
SYNCHROTRON RADIATION
VISIBLE RADIATION