Efficient synthetic methods for carbazole-based small molecule electron donors with donor–acceptor (D–A) and A–D–A type structures were developed. In order to study the relation between chemical structures and material properties, the prepared compounds were characterized in detail using absorption spectroscopy, differential pulse voltammetry, and computational methods. In addition, symmetrical A–D–A type compounds were tested as an active layer component in bulk heterojunction based organic solar cell (OSC) devices with conventional structure. The results show that the two compound types have many similar properties. However, the extended molecular structure of A–D–A type compounds offer better film forming properties and higher molar absorption coefficients compared with the D–A type materials. Furthermore, the attachment of fluoro substituents in the A units has a positive effect on all solar cell device parameters. Moreover, the computational studies revealed that the molecular structures are twisted between the central carbazole D unit and π-bridge which may result in inefficient intramolecular charge transfer and, also, relatively limited short-circuit currents in OSC devices.

开发了一种高效的合成方法，用于咔唑基小分子电子供体的施主-受主（D - A）和A - D - A型结构。为了研究化学结构与材料性能之间的关系，使用吸收光谱，差分脉冲伏安法和计算方法对制备的化合物进行了详细表征。此外，对称的A – D – A在具有常规结构的基于体异质结的有机太阳能电池（OSC）器件中，测试了两种类型的化合物作为活性层成分。结果表明，两种化合物类型具有许多相似的性质。但是，与D – A型材料相比，A – D – A型化合物的扩展分子结构具有更好的成膜性和更高的摩尔吸收系数。此外，氟取代基在A单元中的附着对所有太阳能电池器件参数都有积极影响。此外，计算研究表明，分子结构在中心咔唑D单元和π-桥可能会导致分子内电荷转移效率低下，并且还会导致OSC器件中的短路电流相对有限。