聚噻吩-卟啉-富勒烯分子薄膜中光诱导电子转移的动力学

Kinetics of photoinduced electron transfer in polythiophene-porphyrin-fullerene molecular films.

作者信息

Vuorinen Tommi, Kaunisto Kimmo, Chukharev Vladimir, Tkachenko Nikolai V, Efimov Alexandre, Lemmetyinen Helge

机构信息

Institute of Materials Chemistry, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland.

出版信息

J Phys Chem B. 2006 Oct 5;110(39):19515-20. doi: 10.1021/jp063076b.

DOI:10.1021/jp063076b

PMID:17004813

Abstract

Photoinduced electron transfer (ET) processes were studied by the time-resolved Maxwell displacement charge (TRMDC) method in bilayer structures consisting of an electron donor-acceptor and conductive polymer monolayers, porphyrin-fullerene dyad and polyhexylthiophene, respectively, both layers prepared by the Langmuir-Blodgett (LB) method. The charge separation involves two fast steps: an intramolecular ET in the dyad molecule followed by an interlayer ET from the polymer to the formed porphyrin radical cation. These fast vertical intra- and interlayer processes could not be time-resolved by the TRMDC method. The lifetime of the charge separated state in the system was extended to hundreds of milliseconds by lateral electron and hole transfers in fullerene and polymer sublayers. The kinetics of the system was described by a model involving two long-living energetically different complete charge separated states. The data analysis indicates that the charge separation has a recombination time of 0.5 s. This is a promising result for possible applications.

摘要

通过时间分辨麦克斯韦位移电荷（TRMDC）方法，在由电子供体 - 受体和导电聚合物单分子层、卟啉 - 富勒烯二元体系和聚己基噻吩分别组成的双层结构中研究了光诱导电子转移（ET）过程，这两层均通过朗缪尔 - 布洛杰特（LB）方法制备。电荷分离涉及两个快速步骤：二元分子内的分子内电子转移，随后是从聚合物到形成的卟啉自由基阳离子的层间电子转移。这些快速的垂直层内和层间过程无法通过TRMDC方法进行时间分辨。通过富勒烯和聚合物子层中的横向电子和空穴转移，系统中电荷分离态的寿命延长至数百毫秒。该系统的动力学由一个涉及两个能量不同的长寿命完全电荷分离态的模型描述。数据分析表明电荷分离的复合时间为0.5秒。这对于可能的应用来说是一个很有前景的结果。