Low-temperature dynamics of weakly localized Frenkel excitons in disordered linear chains

被引:65
作者
Bednarz, M
Malyshev, VA
Knoester, J
机构
[1] Univ Groningen, Inst Theoret Phys, NL-9747 AG Groningen, Netherlands
[2] Univ Groningen, Ctr Mat Sci, NL-9747 AG Groningen, Netherlands
[3] SI Vavilov State Opt Inst, St Petersburg 199034, Russia
关键词
D O I
10.1063/1.1643720
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
We calculate the temperature dependence of the fluorescence Stokes shift and the fluorescence decay time in linear Frenkel exciton systems resulting from the thermal redistribution of exciton population over the band states. The following factors, relevant to common experimental conditions, are accounted for in our kinetic model: (weak) localization of the exciton states by static disorder, coupling of the localized excitons to vibrations in the host medium, a possible nonequilibrium of the subsystem of localized Frenkel excitons on the time scale of the emission process, and different excitation conditions (resonant or nonresonant). A Pauli master equation, with microscopically calculated transition rates, is used to describe the redistribution of the exciton population over the manifold of localized exciton states. We find a counterintuitive nonmonotonic temperature dependence of the Stokes shift. In addition, we show that depending on experimental conditions, the observed fluorescence decay time may be determined by vibration-induced intraband relaxation, rather than radiative relaxation to the ground state. The model considered has relevance to a wide variety of materials, such as linear molecular aggregates, conjugated polymers, and polysilanes. (C) 2004 American Institute of Physics.
引用
收藏
页码:3827 / 3840
页数:14
相关论文
共 51 条
[1]  
Agranovich V.M., 1982, Electronic Excitation Energy Transfer in Condensed Matter
[2]   Absorption spectra of mixed two-dimensional cyanine aggregates on silver halide substrates [J].
Bakalis, LD ;
Rubtsov, I ;
Knoester, J .
JOURNAL OF CHEMICAL PHYSICS, 2002, 117 (11) :5393-5403
[3]  
Bakalis LD, 1999, J PHYS CHEM B, V103, P6620, DOI 10.1021/jp990354gCCC:$18.00
[4]   Linear absorption as a tool to measure the exciton delocalization length in molecular assemblies [J].
Bakalis, LD ;
Knoester, J .
JOURNAL OF LUMINESCENCE, 2000, 87-9 (87) :66-70
[5]  
BASIEV TT, 1987, SPECTROSCOPY SOLIDS, P275
[6]   Temperature dependent fluorescence in disordered Frenkel chains: Interplay of equilibration and local band-edge level structure [J].
Bednarz, M ;
Malyshev, VA ;
Knoester, J .
PHYSICAL REVIEW LETTERS, 2003, 91 (21)
[7]   Disorder-induced temperature dependence of the radiative lifetime of Frenkel excitons in molecular aggregates [J].
Bednarz, M ;
Malyshev, VA ;
Lemaistre, JP ;
Knoester, J .
JOURNAL OF LUMINESCENCE, 2001, 94 :271-274
[8]   Intraband relaxation and temperature dependence of the fluorescence decay time of one-dimensional Frenkel excitons: The Pauli master equation approach [J].
Bednarz, M ;
Malyshev, VA ;
Knoester, J .
JOURNAL OF CHEMICAL PHYSICS, 2002, 117 (13) :6200-6213
[9]   Site torsional motion and dispersive excitation hopping transfer in π-conjugated polymers [J].
Brunner, K ;
Tortschanoff, A ;
Warmuth, C ;
Bässler, H ;
Kauffmann, HF .
JOURNAL OF PHYSICAL CHEMISTRY B, 2000, 104 (16) :3781-3790
[10]   Scaling of fluorescence Stokes shift and superradiance coherence size in disordered molecular aggregates [J].
Chernyak, V ;
Meier, T ;
Tsiper, E ;
Mukamel, S .
JOURNAL OF PHYSICAL CHEMISTRY A, 1999, 103 (49) :10294-10299