Elementary excitations in electroluminescent one-dimensional conjugated polymers

电致发光一维共轭聚合物的基本激发

基本信息

批准号：
09440116
负责人：
KURODA Shin-ichi
金额：
$ 1.6万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09440116/
关键词：
Conjugated polymers Electroluminescent polymers Nonlinear excitations Polaron ESR ENDOR One-dimensional electron system

项目摘要

Recent discovery of electroluminescence in a polymer, poly (phenylene vinylene) , PPV has brought much attention to polarons, a nonlinear excitation in one-dimensional conjugated polymers, as a candidate of charge carriers responsible for electroluminescence through charge recombination. We have shown that ESR and ENDOR spectroscopies are useful in observing the microscopic shapes of paramagnetic excitations in conjugated polymers. The purpose of the present project is to conduct ESR and ENDOR observations of polarons generated by light illumination, doping etc. in PPV and its derivatives and to develop a theoretical model to analyze the data to obtain the polaron shapes as well as the electronic states of polymers.In this year, we have been successful in determining the detailed shape of polarons in PPV and the magnitudes of Coulomb interactions affecting the shape by analyzing the ENDOR and newly obtained TRIPLE (electon-nuclear-nuclear triple resonance) data of trapped polarons in the dark state of the polymer, provided from Dr. T.Ohnishi of Sumitomo Chemical Co. The obtained results with the maximum spin densities reside on vinylene sites successfully explained the reduction of ODESR linewidth in a derivative, cyano-PPV where the protons of vinylene sites are substituted by cyano groups, reported by British and American groups. The results have been published in JPSJ.In addition to these, light-induced ESR (LESR) of photogenerated polarons has been successfully detected in cyano-substituted PPV derivatives provided from Prof. R.H.Friend of Cavendish Laboratory. The analysis of the observed LESR line shapes as well as the excitation spectra of LESR intensities are currently under progress to study the effect of molecular structures on the polaron shapes and the electronic states of one-dimensional polymers.

最近发现的聚合物（聚亚苯基亚乙烯基）PPV 中的电致发光引起了人们对极化子（一维共轭聚合物中的非线性激发）的广泛关注，它作为通过电荷重组负责电致发光的电荷载流子的候选者。我们已经证明，ESR 和 ENDOR 光谱可用于观察共轭聚合物中顺磁激发的微观形状。本项目的目的是对PPV及其衍生物中光照射、掺杂等产生的极化子进行ESR和ENDOR观测，并建立理论模型来分析数据以获得极化子形状以及电子态今年，我们通过分析 ENDOR 和新获得的 TRIPLE（电子-核-核三重共振）数据，成功确定了 PPV 中极化子的详细形状以及影响形状的库仑相互作用的大小。住友化学公司的 T.Ohnishi 博士提供了聚合物暗态下捕获的极化子。所获得的最大自旋密度位于亚乙烯基位点的结果成功地解释了衍生物氰基-PPV 中 ODESR 线宽的减小，其中据英国和美国研究小组报道，亚乙烯基位点的质子被氰基取代。该结果已发表在《JPSJ》上。除此之外，在卡文迪什实验室的R.H.Friend教授提供的氰基取代的PPV衍生物中也成功检测到了光生极化子的光致ESR（LESR）。目前正在对观察到的 LESR 线形以及 LESR 强度的激发光谱进行分析，以研究分子结构对一维聚合物的极化子形状和电子态的影响。