Dispersion of Resonant Raman Scattering in {ital {pi}} -Conjugated Polymers: Role of the Even Parity Excitons

Journal Article · Mon Sep 01 04:00:00 EDT 1997 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.79.1762· OSTI ID:664460

Ozaki, M; Benner, R E; Vardeny, Z V ^[1]; Ozaki, M; Yoshino, K ^[2]; Ehrenfreund, E ^[3]; Barton, T J ^[4]

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1. Departments of Physics and Electrical Engineering, University of Utah, Salt Lake City, Utah 84112 (United States)
2. Department of Electronic Engineering, Osaka University, Suita Osaka 565 (Japan)
3. Department of Physics and Solid State Institute, The Technion, Haifa 32000 (Israel)
4. Department of Chemistry, Iowa State University, Ames, Iowa 50011 (United States)

Resonant Raman scattering dispersion of the most strongly coupled phonon frequencies with the excitation laser photon energy is measured in terms of a dispersion rate parameter D and quantified in a variety of {pi} conjugated polymer films. D was found to be large in nonluminescent polymers and small in luminescent polymers. We show that D is determined by the dependence of the {ital even} parity excitons (A{sub g}) on the polymer conjugation length, and this may serve as a useful spectroscopy for the 2A{sub g} exciton in nonluminescent polymers where it is otherwise optically inactive. {copyright} {ital 1997} {ital The American Physical Society}

• DOE Contract Number: FG03-93ER45490
• OSTI ID: 664460
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 9 Vol. 79; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DISPERSION RELATIONS
EXCITED STATES
EXCITONS
PHONONS
POLYMERS
RAMAN SPECTRA
RESONANCE
THIN FILMS