共轭聚合物单分子能量转移的量子相干效应研究

项目名称： 共轭聚合物单分子能量转移的量子相干效应研究

项目编号： No.11504216

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 陈瑞云

作者单位： 山西大学

项目金额： 24万元

中文摘要： 共轭聚合物单分子能量转移中的量子相干效应是影响基于共轭聚合物的单分子器件性能及有机器件中能量转移有效操控的重要特性。本项目旨在研究MEH-PPV共轭聚合物单分子的分子内和分子间能量转移的量子相干效应。利用低温环境抑制声子效应使单分子荧光光谱变窄、能量转移供体和受体光谱易于区分的特性，研究伸展和折叠时单个共轭聚合物分子中分子内和分子间能量转移，测量能量转移效率；采用飞秒脉冲泵浦-探测技术，测量共轭聚合物单分子供体和受体发色团强耦合和弱耦合情况下能量转移的量子相干时间；改变共聚物单分子所处环境温度，研究环境退相干对能量转移效率的影响。通过施加电场调节供体和受体的相互作用，实现能量转移过程中的量子相干调控。相关研究将为进一步实现共轭聚合物能量转移的操控以及制备新型有机光量子器件奠定基础。

中文关键词： 单分子；共轭聚合物；量子相干；能量转移

英文摘要： The role of quantum coherence in energy transfer of single conjugated polymer molecule is particular important for the performance of single molecular optoelectronic devices based on conjugated polymer and for the effective control and manipulation of energy transfer in organic devices. Considering the suppression of phonon effect at low temperature, we devote to investigate the role of quantum coherence in intramolecular and intermolecular energy transfer in single MEH-PPV conjugated polymer molecule. By using the characteristic of narrow spectral of single molecules at low temperature to distinguish donor and acceptor chromophores, the intramolecular and intermolecular energy transfer rate can be extracted from extended and folded single conjugated polymer molecule. Here, femtosecond pulse laser is divided into two pulses with tunable delay time to excite the single molecules. The quantum coherence time of strong and weak electronic coupling between donor and acceptor chromophores can be investigated by changing the time delay of pump-probe pulses and detecting the resulting fluorescence fluctuation. We will also measure the role of environment induced decoherence in energy transfer by altering the temperature. Moreover, the interplay between donor and acceptor chromophores can be controlled by external electric field, which makes it possible to control the quantum coherence in energy transfer. The research will lay the foundations for the further control of energy transfer in conjugated polymer and the development of new type of organic quantum optical devices.

英文关键词： single molecule;conjugated polymer;quantum coherence ;energy transfer