Interface properties and electronic structure of new organic low band gap materials

低带隙（LBG）聚合物是光电器件（如有机太阳能电池或发光二极管）中有活性有机层的有前途的候选者。这些材料在器件中的性能受到其在薄膜中的形态和自组织能力的强烈影响。在第一个资助期内，已经表明（额外的）烷基噻吩基团可以显著改善LBG聚合物薄膜的成膜性能。本文的首要目标是系统地研究在LBG聚合物结构中引入具有不同取代模式的乙烯间隔单元对电子性能和自组织能力的影响。该联合项目的第二个重点是合成和表征新的具有不同程度烷基化的双酮吡咯（DPP）基供体-受体共聚物。我们将研究平面化/阶梯化程度如何影响薄膜的有序性和电子性能。薄膜和界面的实验研究将使用各种互补的光谱和微观技术进行，这些技术将提供关于薄膜中（界面）电子结构和组织的广泛而详细的信息。这包括光发射和各种光谱学，除了原子力和电子显微镜。

Low band gap (LBG) polymers are promising candidates for activeorganic layers in opto-electronic devices, such as organic solar cellsor light emitting diodes. The properties of these materials in devicesare strongly influenced by their morphology and ability for selforganizationin thin-films. It was already shown within the first fundingperiod that (additional) alkyl-thiophene moieties can improve distinctlyfilm forming properties in thin films of LBG polymers. A systematicinvestigation of the influence of the introduction of thienylene spacerunits with different substitution pattern in LBG polymer structures onboth electronic properties and the ability for self-organization is thefirst goal of this proposal. The second focus of the joint project is thesynthesis and characterization of new diketopyrrolopyrrole (DPP)-based donor-acceptor co-polymers with a varying degree ofladderization. We will investigate how the degree ofplanarization/ladderization influences the ordering and electronicproperties in thin films. The experimental investigations of thin filmsand interfaces will be carried out using a variety of complementaryspectroscopic and microscopic techniques that shall provide wide anddetailed information on both (interfacial) electronic structure andorganization in thin films. That includes photoemission and variousoptical spectroscopies in addition to atomic force and electronmicroscopy.