Systematic study of the vibrational properties of poly(phenylene vinylene) and related oligomers

Journal Article · Thu Sep 01 00:00:00 EDT 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.50.6068· OSTI ID:6981600

Wang, W Z; Saxena, A; Bishop, A R ^[1]

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1. Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

Within a two-dimensional Su-Schrieffer-Heeger-like Hamiltonian, the electronic and vibrational properties of poly(phenylene vinylene) (PPV) and its model oligomers are investigated systematically. The stable geometric and electronic configurations of this PPV series are determined within the Bogoliubov--de Gennes formalism, with good agreement with the observed variation of the electronic gap with chain length, and the observed spatial extent of the nonlinear excitations (polarons, bipolarons, etc.). The dynamics of lattice relaxation subsequent to electron dopoing is also analyzed, and suggests relatively weak [ital e]-ph coupling in this system. The two-dimensional vibrational spectra of the PPV series have been obtained in the random-phase and frozen-phonon approximations, and certain doping-induced localized modes are identified to be either ir or Raman active. The ir, Raman, and resonant Raman spectra of the pristine and charged PPV series are calculated and compared carefully with corresponding experiments, with overall good agreement.

• OSTI ID: 6981600
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 50:9; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
POLYPHENYLS
VIBRATIONAL STATES
POLYVINYLS
ELECTRON-PHONON COUPLING
RAMAN SPECTRA
RANDOM PHASE APPROXIMATION
TWO-DIMENSIONAL CALCULATIONS
AROMATICS
COUPLING
ENERGY LEVELS
EXCITED STATES
HYDROCARBONS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
POLYMERS
SPECTRA
360606* - Other Materials- Physical Properties- (1992-)