Fluorescence spectrum of a blue-phase polydiacetylene obtained by probe saturation spectroscopy
✍ Scribed by A. Yasuda; M. Yoshizawa; T. Kobayashi
- Book ID
- 103035722
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 540 KB
- Volume
- 209
- Category
- Article
- ISSN
- 0009-2614
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✦ Synopsis
The dependence of the transient difference transmission spectrum on probe-light intensity was investigated for a blue-phase polydiacetylene with side groups of substituted urethanes. The spectra of stimulated emission and photoinduced absorption of the lowest 'Et, exciton were separately determined in the polymer, which exhibits extremely weak fluorescence with quantum efficiency c lo-' and ultrashort lifetime of 140 fs, by "probe saturation spectroscopy" newly proposed here. The fluorescence spectrum calculated from the stimulated emission spectrum has a peak near 1.9 eV and is an approximate mirror image to the stationary absorption spectrum. The relaxation time constant from the higher excited state m 'A, exciton to the lowest 'B, exciton is estimated to be shorter than 50 fs.