| AVS 55th International Symposium & Exhibition | |
| Synchrotron-based Spectroscopy and Spectro-Microscopy Topical Conference | Tuesday Sessions |
| Session SY+SS+BI-TuM |
| Session: | Synchrotron-based Spectroscopy and Spectro-Microscopy |
| Presenter: | J.F. Zhu, University of Science and Technology of China |
| Authors: | Y.X. Guo, University of Science and Technology of China W. Zhao, University of Science and Technology of China X.F. Feng, University of Science and Technology of China L. Zhang, University of Science and Technology of China W.H. Zhang, University of Science and Technology of China J.F. Zhu, University of Science and Technology of China |
| Correspondent: | Click to Email |
Interfaces of metal/polyfluorene have attracted much research interests in both technological and scientific point of view. Polyfluorene-based light emitting devices have been proved to have a high luminescene effciency. However, the occurrence of gap states in most cases will affect the luminescence properties of organic materials. In this paper, the interface formation and energy level alighment for Ca/PDHFV and Ca/PHF have been studied by synchrotron radiation photoemission spectroscopy (SRPES) and X-ray photoelectron spectroscopy (XPS). The results imply that the chemical reaction at the interface of Ca/PDHFV is stronger than that of Ca/PHF. However, no gap states at the Ca/PDHFV interface can be observed, which is different from the observations on Ca/PHF. Both of these two interfaces display low electron injection barrier. Our findings suggest that the gap states can be removed at metal/polyfluorene interface by introducing vinylene units into polyfluorene, which may provide a new way to eliminate the gap states.