Third-order nonlinear optical properties in the excited state of well-defined thiophene-dimethylsilyl co-oligomers - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Physical Chemistry B Année : 1998

Third-order nonlinear optical properties in the excited state of well-defined thiophene-dimethylsilyl co-oligomers

Résumé

A new series of oligomers for nonlinear optics (NLO), the thiophene−dimethylsilyl co-oligomers, (TSi)n−T with n = 1−3, have been synthesized in order to combine third-order NLO response and transparency in the visible region. Stationary-state absorption spectra, fluorescence spectra, and time-resolved absorption (picosecond) have been carried out. In sharp contrast with oligothiophenes, the absorption spectra of (TSi)n−T are not red-shifted as n increases, but as for short oligothiophenes their quantum yield of fluorescence is low because of the competitive triplet-state formation and their emission wavelength range is remarkably solvent-independent. These data show slight increase of the dipole moment between the S0 ground state and the S1 excited state, in agreement with theoretical calculations (ZINDO method). Fast intersystem crossing is observed between singlet and triplet states and S1 → Sn and T1 → Tn spectra have been measured. Optical nonlinearity (γ) of the excited state has been measured and compared to the terthiophene. The large molecular second hyperpolarizability of the silyl derivatives associated with their interesting transparency properties shows that such oligomers may be considered, in the excited state, as promising molecules for nonlinear applications.
Fichier non déposé

Dates et versions

hal-01550251 , version 1 (29-06-2017)

Identifiants

  • HAL Id : hal-01550251 , version 1

Citer

C. Moreau, F. Serein-Spirau, J. F. Letard, R. Lapouyade, Gediminas Jonusauskas, et al.. Third-order nonlinear optical properties in the excited state of well-defined thiophene-dimethylsilyl co-oligomers. Journal of Physical Chemistry B, 1998, 102 (9), pp.1487-1497. ⟨hal-01550251⟩

Collections

CNRS LOMA
23 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More