Dynamics of photoexcited charge carriers in self-organized organic bulk semiconductors

自组织有机体半导体中光激发载流子的动力学

• 批准号: 220464899
• 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: Research Units
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/220464899?language=en
• 关键词: Dynamics; photoexcited; charge; carriers; self

The overall project goal is to develop a fundamental understanding of the influence of molecular order on the dynamics of the processes, occurring in molecular bulk semiconductors with variable architecture, along the whole process chain, from light absorption to charge carrier transport. For organic bulk semiconductors, both local and macroscopic mobilities are of importance. The former reflects the potential of the material itself, the second is the essential parameter for device applications. Ideally, one needs to know the whole picture to recognize the application potential of any newly developed material and to deliver feedback on its optimisation: either of the material itself (in case of low local mobility) or of the device under test (macroscopic mobility by far lower than local mobility). In the next project phase, we will apply the method of transient microwave conductivity (TRMC) for selected materials, polymers and oligomers, provided by the FOR 1809 partners, to investigate their microscopic transport properties. TRMC is based on the fact that charge carriers, generated by a light pulse, lead to dielectric losses in the material under study (microwave absorption). A quantitative analysis of TRMC measurements, however, is only possible, if the charge carrier density is known. Therefore, measurement of the microwave response should ideally be done together with measurements of optical density via, e.g. transient absorption (TA) under the same conditions. In the first funding period we succeeded in the construction of a combined set-up, which allows, to carry out both TRMC and TA simultaneously, on the same sample during the same laser excitation pulse, while even including a cryostat for temperature-dependent measurements. We will use this method to systematically study macromolecules based on squaraine conjugates. In contrast to that, indolenine-squaraines can be produced specifically in the form of stretched zig-zag or helical polymer structures. Therefore it is interesting to investigate the influence of the superstructure on the local charge carrier transport. Further, we plan to perform TA/TRMC studies on hierarchical perylenbisimide derivates, forming Jaggregates, which are liquid crystalline in bulk, but may also form aggregates in liquid solution. Again, it will be interesting to find the influence of the aggregate state on local charge dynamics and transport properties. To address the macroscopic conductivity properties of photovoltaic devices, we will perform transient conductivity measurements, such as OTRACE, TDCF, ToF, TPV/TPC. Theoretical analysis will be done in collaboration with the theory partners within the research group.

项目的总体目标是对分子顺序对过程动力学的影响有一个基本的了解，这种影响发生在具有可变结构的分子体半导体中，沿着整个过程链，从光吸收到载流子传输。对于有机块体半导体，局部和宏观迁移率都很重要。前者反映了材料本身的潜力，后者是器件应用的必备参数。理想情况下，人们需要了解整体情况，以认识任何新开发材料的应用潜力，并提供有关其优化的反馈：材料本身（在局部迁移率较低的情况下）或被测设备（宏观迁移率远低于本地流动性）。在下一阶段的项目中，我们将应用 FOR 1809 合作伙伴提供的选定材料、聚合物和低聚物的瞬态微波电导率 (TRMC) 方法来研究它们的微观传输特性。 TRMC 的基础是光脉冲产生的电荷载流子会导致所研究材料的介电损耗（微波吸收）。然而，只有在载流子密度已知的情况下，才能对 TRMC 测量进行定量分析。因此，理想情况下，微波响应的测量应与光密度的测量一起进行，例如通过相同条件下的瞬态吸收（TA）。在第一个资助期间，我们成功构建了一个组合装置，该装置允许在同一激光激发脉冲期间对同一样品同时进行 TRMC 和 TA，甚至还包括用于温度相关测量的低温恒温器。我们将使用这种方法系统地研究基于方酸菁缀合物的大分子。与此相反，假吲哚-方酸菁可以以拉伸之字形或螺旋聚合物结构的形式具体生产。因此，研究上部结构对局部载流子传输的影响是很有趣的。此外，我们计划对多级苝双酰亚胺衍生物进行 TA/TRMC 研究，形成 Jaggregates，其在本体中是液晶，但也可能在液体溶液中形成聚集体。同样，发现聚集态对局部电荷动力学和传输特性的影响将会很有趣。为了解决光伏器件的宏观电导率特性，我们将进行瞬态电导率测量，例如 OTRACE、TDCF、ToF、TPV/TPC。理论分析将与研究小组内的理论合作伙伴合作完成。

项目成果

Singlet Exciton Diffusion in Organic Crystals Based on Marcus Transfer Rates.

• DOI: 10.1021/ct500014h
• 发表时间: 2014-02
• 期刊: Journal of chemical theory and computation
• 影响因子: 5.5
• 作者: V. Stehr;R. Fink;B. Engels;J. Pflaum;C. Deibel

Direct Observation of Spin States Involved in Organic Electroluminescence Based on Thermally Activated Delayed Fluorescence

基于热激活延迟荧光直接观察有机电致发光中涉及的自旋态

• DOI: 10.1002/adom.201600926
• 发表时间: 2017
• 期刊: Advanced Optical Materials
• 影响因子: 9
• 作者: S. Väth;K. Tvingstedt;M. Auth;A. Sperlich;A. Dabuliene;J. V. Grazulevicius;P. Stakhira;V. Cherpak;V. Dyakonov
• 通讯作者: V. Dyakonov

Photophysics of Deep Blue Acridane- and Benzonitrile-Based Emitter Employing Thermally Activated Delayed Fluorescence

• DOI: 10.1021/acs.jpcc.8b08716
• 发表时间: 2018-10-04
• 期刊: JOURNAL OF PHYSICAL CHEMISTRY C
• 影响因子: 3.7
• 作者: Drigo, Nikita A.;Kudriashova, Liudmila G.;Dyakonov, Vladimir
• 通讯作者: Dyakonov, Vladimir

Anisotropy of singlet exciton diffusion in organic semiconductor crystals from ab initio approaches.

• DOI: 10.1063/1.4858464
• 发表时间: 2014-01
• 期刊: The Journal of chemical physics
• 作者: V. Stehr;B. Engels;C. Deibel;R. Fink

Effects of characteristic length scales on the exciton dynamics in rubrene single crystals

• DOI: 10.1103/physrevb.90.205305
• 发表时间: 2014-11-17
• 期刊: PHYSICAL REVIEW B
• 影响因子: 3.7
• 作者: Gieseking, Bjoern;Schmeiler, Teresa;Pflaum, Jens
• 通讯作者: Pflaum, Jens