Correlation between electronic and optical properties of materials used in printed organic solar cells (Project 7)

印刷有机太阳能电池所用材料的电子和光学特性之间的相关性（项目7）

• 批准号: 511599979
• 负责人: Professor Dr. Dietrich R. T. Zahn
• 金额: --
• 依托单位: Professur Halbleiterphysik
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/511599979?language=en
• 关键词: Correlation; between; electronic; optical; properties

In this project we apply photoemission spectroscopy (PES) and inverse photoemission spectroscopy (IPES) as well as spectroscopic ellipsometry (SE) for the determination of electronic and optical properties, respectively, of neat non-fullerene acceptor (NFA), donor, and multiblock co-oligomers layers and donor-acceptor blends as-prepared and as a function of various ageing processes. PES and IPES deliver information on the densities of occupied states and unoccupied states, respectively, from which valuable parameters such as the work function, the ionization energy, the electron affinity, and thus the transport or single particle bandgap can be derived. Ellipsometry spectra, on the other hand, are defined by the joint density of states and provide the dielectric function respectively the optical constants, from which the optical bandgap can be derived. Moreover, SE can be employed to determine thin film thicknesses, composition and compositional gradients, optical anisotropies induced by molecular orientation, surface and interface roughnesses, as well as horizontal and vertical inhomogeneities. There are three research foci in this project, namely the investigations of a) neat NFA, donor, and multiblock co-oligomers layers, b) donor-acceptor blends, and c) the influence of degradation/ageing processes. Regarding neat layers we study available NFAs, donors, and novel NFA-containing multiblock co-oligomers synthesized within the Research Unit. The parameters obtained serve as reference data and as input for the device modelling within the Research Unit. The second focus lies on donor-acceptor blends and PES/IPES in combination with SE deliver the same valuable parameters as for neat layers. However, the role of SE becomes more important as it can be employed to investigate the morphology by using effective medium approximation (EMA) approaches. EMA modelling delivers information on the intermixing of donors and acceptors and phase separation. Approaches beyond the common EMA approaches are addressed to detect interaction-induced effects in both spin-coated and printed blends as a function of processing parameters. SE is further employed to investigate inhomogeneities of blended layers both lateral and in depth. Finally, we focus on degradation/ageing processes of blended layers using mainly SE and its in situ monitoring capabilities.

在这个项目中，我们应用光电子能谱（PES）和逆光电子能谱（IPES）以及光谱椭圆偏振法（SE）的电子和光学性质的测定，分别为净非富勒烯受体（NFA），供体，和多嵌段共低聚物层和供体-受体共混物作为制备和作为各种老化过程的函数。PES和IPES分别提供关于占据态和未占据态的密度的信息，从这些信息中可以导出有价值的参数，例如功函数、电离能、电子亲和势，从而可以导出传输或单个粒子带隙。另一方面，椭圆偏振光谱由联合态密度定义，并分别提供介电函数和光学常数，从中可以导出光学带隙。此外，SE可以用来确定薄膜厚度，成分和成分梯度，光学各向异性诱导的分子取向，表面和界面粗糙度，以及水平和垂直的不均匀性。该项目有三个研究重点，即a）纯NFA、供体和多嵌段共聚低聚物层的研究，B）供体-受体共混物的研究，以及c）降解/老化过程的影响。关于整齐的层，我们研究可用的NFA，捐助者，和新的NFA含多嵌段共聚低聚物内的研究单位合成。所获得的参数作为参考数据，并作为研究单位内器械建模的输入。第二个焦点在于供体-受体共混物和PES/IPES与SE组合提供与纯层相同的有价值的参数。然而，SE的作用变得更加重要，因为它可以通过使用有效介质近似（EMA）方法来研究形态。EMA建模提供了关于供体和受体的混合以及相分离的信息。超越常见的EMA方法的方法被解决，以检测相互作用引起的影响，在旋涂和印刷的共混物作为一个函数的处理参数。SE进一步被用来调查混合层的横向和深度的不均匀性。最后，我们专注于降解/老化过程的混合层主要使用SE和原位监测能力。