Abstract
Angle resolved near-edge absorption fine structure measurements of the C 1s edge of a film of the star-shaped molecule 4(HPBT) show a high degree of order, with the molecules maintaining a largely planar geometry in an upright configuration. X-ray excited optical luminescence measurements showed a dependence of the luminescence spectrum on the excitation energy, with (0-0), (0-1), and (0-2) vibrational modes being clearly visible when exciting off-resonance; the appearance of these features under off-resonance is attributed to a scattering process that is quenched when the excitation approaches a core absorption resonance. The HOMO-LUMO gap is estimated from the luminescence measurements (2.28 eV), and this value is confirmed by the comparison of the C 1s absorption and C Kα emission spectra.
Original language | English |
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Pages (from-to) | 355-359 |
Number of pages | 5 |
Journal | Journal of Electron Spectroscopy and Related Phenomena |
Volume | 184 |
Issue number | 7 |
DOIs | |
Publication status | Published - 2011 Jul |
Bibliographical note
Funding Information:We gratefully acknowledge the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canada Research Chair program. D.H. Choi thanks the support by a grant from the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Knowledge Economy, Republic of Korea (M2007010004). The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The Canadian Light Source is supported by NSERC, NRC, CIHR, and the University of Saskatchewan.
Keywords
- NEXAFS
- Soft X-ray emission spectroscopy
- XEOL
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Radiation
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Spectroscopy
- Physical and Theoretical Chemistry