Coherent Mechanism of Exciton Transport in Disordered J-Aggregates

详细信息    查看全文

• 作者：Alexander N. Lebedenko ; Roman S. Grynyov ; Gleb Ya. Guralchuk ; Alexander V. Sorokin ; Svetlana L. Yefimova ; Yuri V. Malyukin
• 刊名：Journal of Physical Chemistry C
• 出版年：2009
• 出版时间：July 23, 2009
• 年：2009
• 卷：113
• 期：29
• 页码：12883-12887
• 全文大小：121K
• 年卷期：v.113,no.29(July 23, 2009)
• ISSN：1932-7455

文摘

Using a luminescent exciton trap, a mechanism of the exciton migration in disordered J-aggregates of amphiphilic analogue of pseudoisocyanine (amphi-PIC) dye has been investigated in the temperature range of 80−300 K. Due to a strong topological disorder in amphi-PIC J-aggregates observed in a binary dimethylformamide−water (DMF/W) solution with a low water content, two types of excitonic states have been revealed, delocalized exciton state that forms the main part of the J-aggregates absorption band (J-band) and a state of strongly localized excitons that forms the long-wavelength edge of the J-band. These excitonic states are characterized by the different mechanism of the exciton transport: a coherent mechanism for delocalized excitons and an incoherent one for localized excitons. As localized excitons provide a small contribution to the J-band and appear only at high degree of topological disorder, the coherent mechanism of the exciton transport in amphi-PIC J-aggregates has been concluded. Such a result is nontrivial due to a small delocalization length of excitons in amphi-PIC J-aggregates (11 monomers at 80 K) provided by the moderate energetic disorder and strong exciton−phonon coupling.