Ultrafast Dynamics of Electronic Excitations in Single Conjugated Polymer Chains

单共轭聚合物链中电子激发的超快动力学

• 批准号: 260342502
• 负责人: Professor Dr. Richard Hildner
• 金额: --
• 依托单位: Lehrstuhl für Experimentalphysik II (Optoelektronik weicher Materie)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/260342502?language=en
• 关键词: Ultrafast; Dynamics; Electronic; Excitations; Single

The ultrafast transport dynamics of electronic excitations is a key process in the initial steps of solar energy conversion in organic photovoltaic devices based on p-conjugated polymers. However, the electronic structure of this material class, and in particular the ultrafast (sub-picosecond) formation and transport dynamics of electronic excitations is still not entirely clear and controversially discussed. Although these processes can in principle be investigated by conventional ultrafast ensemble spectroscopy, the development of a detailed understanding is hampered by the large structural and electronic heterogeneity of conjugated polymers. In this project we will therefore employ ultrafast single-molecule spectroscopy to study the properties of a prototypical and technologically important system, oligo- and polythiophenes, on a molecular scale. We aim at resolving the femtosecond formation of fundamental electronic excitations as well as their subsequent transport dynamics within single thiophene chains by measurements as a function of the thiophene chain length, their local environment, and the temperature. We want to retrieve the time scales, the relaxation energies, and the relaxation pathways of electronic excitations during their initial formation and localisation. Moreover, we will investigate the various factors that influence the intra-chain energy transport, such as the precise chain conformation, the electronic interactions, as well as the role of and the coupling to the local chain environment. A particular focus will be to resolve potential coherent transport on ultrashort (< 250 fs) time scales and to identify the relevant parameters that impact on the coherence lifetime.

电子激发的超快传输动力学是基于P偶联聚合物的有机光伏设备中太阳能转化的初始步骤中的关键过程。但是，该材料类别的电子结构，尤其是电子激发的超快（亚比秒）的形成和传输动力学仍然不完全清楚且有争议。尽管这些过程原则上可以通过常规的超快集合光谱进行研究，但详细理解的发展受到共轭聚合物的较大结构和电子异质性的阻碍。因此，在这个项目中，我们将采用超快的单分子光谱法研究典型和技术重要的系统，寡硫醇和聚息烯的特性。我们旨在通过测量硫芬链长度，当地环境和温度来解决基本电子激发的飞秒形成及其随后在单噻吩链中的运输动力学。我们想检索电子激发在其初始形成和定位期间的时间尺度，松弛能和放松途径。此外，我们将研究影响链内能传输的各种因素，例如精确的链构象，电子相互作用以及与当地链环境的作用和耦合。一个特定的重点是解决超时（<250 fs）时间尺度上的潜在相干运输，并确定影响相干寿命的相关参数。