Journal of Fluorescence

, Volume 5, Issue 4, pp 307–319

Nonradiative excitation energy transport in one-component disordered systems

  • Piotr Bojarski
  • Leszek Kulak
  • Czeslaw Bojarski
  • Alfons Kawski
Article

DOI: 10.1007/BF01152557

Cite this article as:
Bojarski, P., Kulak, L., Bojarski, C. et al. J Fluoresc (1995) 5: 307. doi:10.1007/BF01152557

Abstract

High-accuracy Monte Carlo simulations of the time-dependent excitation probabilityGs(t) and steady-state emission anisotropyrM/r0M for one-component three-dimensional systems were performed. It was found that the values ofrM/r0M obtained for the averaged orientation factor\(\overline {\kappa ^2 } \) only slightly overrate those obtained for the real values of the orientation factor κik2. This result is essentially different from that previously reported. Simulation results were compared with the probability coursesGs(t) andR(t) obtained within the frameworks of diagrammatic and two-particle Huber models, respectively. The results turned out to be in good agreement withR(t) but deviated visibly fromGs(t) at long times and/or high concentrations. Emission anisotropy measurements on glycerolic solutions of Na-fluorescein and rhodamine 6G were carried out at different excitation wavelengths. Very good agreement between the experimental data and the theory was found, with λex≈λ0-0 for concentrations not exceeding 3.5·10−2 and 7.5·10−3M in the case of Na-fluorescein and rhodamine 6G, respectively. Up to these concentrations, the solutions investigated can be treated as one-component systems. The discrepancies observed at higher concentrations are caused by the presence of dimers. It was found that forλex0-0 (Stokes excitation) the experimental emission anisotropies are lower than predicted by the theory. However, upon anti-Stokes excitation (λex0-0), they lie higher than the respective theoretical values. Such a dispersive character of the energy migration can be explained qualitatively by the presence of fluorescent centers with 0-0 transitions differing from the “mean” at λ0-0.

Key words

Energy migrationMonte Carlo simulationfluorescence decayemission anisotropy

Copyright information

© Plenum Publishing Corporation 1995

Authors and Affiliations

  • Piotr Bojarski
    • 1
  • Leszek Kulak
    • 2
  • Czeslaw Bojarski
    • 2
  • Alfons Kawski
    • 1
  1. 1.Institute of Experimental PhysicsUniversity of GdańskGdańsk, Wita Stwosza 57Poland
  2. 2.Department of Applied Mathematics and Technical PhysicsTechnical University of GdańskGdańsk, Majkowskiego 11/12Poland