Hits:

Indexed by:期刊论文

Date of Publication:2011-02-01

Journal:PHYSICA B-CONDENSED MATTER

Included Journals:Scopus、SCIE、EI

Volume:406

Issue:3

Page Number:579-583

ISSN No.:0921-4526

Key Words:J-aggregates; Exchange narrowing; Disorder solids; Frenkel-exciton

Abstract:The effect of segment-size fluctuations on exchange narrowing in a molecular J-aggregate of site-energy disordered distributions is studied using a one-dimensional Frenkel-exciton model. It is found that the segment-size disorder leads to the width of the absorption spectra deviating from the scaling law, sigma(4/3) of the site-energy disordered standard deviation sigma, being suitable for the system only with the site-energy disorder. In larger sigma, the segment-size disorder has little influence on the linear absorption spectra. With increasing segment mean-length, the absorption line width monotonically increases, and then approaches a saturated value. By comparing a system of larger mean-length segment with a smaller one, both with the same segment-size disorder, it is found that the absorption line width of the former is broadened, and the exchange narrowing effect is reduced. The present result shows that the correlation effect can be partially maintained for the system with larger mean-length segment. (C) 2010 Elsevier B.V. All rights reserved.