Interplay between microscopic structure and intermolecular charge transfer processes in polymer-fullerene bulk-heterojunctions

聚合物-富勒烯体异质结微观结构与分子间电荷转移过程之间的相互作用

• 批准号: 65143984
• 负责人: Professor Dr. Vladimir Dyakonov
• 金额: --
• 依托单位: Lehrstuhl für Experimentelle Physik VI
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/65143984?language=en
• 关键词: Interplay; between; microscopic; structure; intermolecular

In this follow-up project we plan to perform systematic studies of charge transfer (CT) processes in polymer semiconductors and their blends with electron acceptor moieties. Our investigations are aimed at clarifying the correlation between CT and film morphology on the microscopic level. In the first application period, we developed a unique set of tools to study film structure on the nanometer scale as well as excited states in organic bulk heterojunction solar cells. We implemented and applied an optically detected magnetic resonance setup, and found surprising results related to formation of triplet excitons with different spatial extent in the conjugated polymer rr-P3HT (regio-regular poly-hexylthiophene). Triplet excitons are generally considered as loss factors in organic photovoltaics. We determined spatial extents of these triplet states ranging from few Ångstroms (molecular triplet excitons) to several nanometers. The latter we identify with CT excitons, or polaron pairs, the precursor state of free charges in organic solar cells—and thus crucial for their performance. The different triplet states occur depending on the film morphology, which we studied by scanning force microscopy (SFM) based nanotomography. SFM-nanotomography was for the first time adapted to study conjugated polymers and donor-acceptor blends by development of a suitable plasma-etching recipe. So far we demonstrated 3D volume imaging with 10 nm resolution of a P3HT:PCBM blend. Although the results of the first proposal period are novel and interesting, the microscopic nature of the triplet states remains unresolved.

在这个后续项目中，我们计划对聚合物半导体中的电荷转移（CT）过程进行研究纳米尺度量表和有机体中的陈述状态均暗示，施用，并被检测到三胞胎激子范围Ångsstroms的Trise三重态的范围使我们使用CT激素识别后者识别后者，这是有机太阳能CELP中的自由电荷的态度。扫描力显微镜（SFM）基于纳米摄影。第一个提案期的结果，旅行状态的微观性质仍然存在。