Photovoltaics is one major pillar on the way to clean and renewable energy production. After reports on the first silicon based solar cells in the 1950ies the field has been steadily growing and many new types of solar cells have been developed. Lately, organic solar cells have attracted increased research interest due to their attractive features, such as strong and tunable light absorption, mechanical flexibility, reduced manufacturing costs and ecological advantages. In these cells, the light absorbing layer is made from a blend of two different organic materials, called donor and acceptor materials, which are based on organic molecules (or polymers). Regardless of the solar cell type, the central research goal - increased efficiency and reduced manufacturing costs, has remained unchanged since the earliest solar cells. In the current project this goal will be addressed in a systematic way by investigation of the structure-properties relationship of novel terrylene-based acceptor molecules. Terrylenes belong to the class of rylene dyes. Perylene derivatives, which are also member of this class, are already well established acceptor materials for organic solar cells. In comparison to perylenes, terrylenes have improved spectral properties, while being synthetically just as accessible, making them interesting for application in solar cells. However, due to their increased molecular size, terrylenes are more prone to a formation of intermolecular aggregates. Such aggregate formation decreases the solubility and, as a result, solar cell fabrication becomes difficult. Furthermore, aggregation of the acceptor molecules decreases the efficiency of electron transfer in a blend with donor materials, which has a direct, negative impact on the solar cells’ performance. In this project we will address this problem. That will be done by preparing an ensemble of terrylene derivatives. The optical and electronical properties of these compounds then will be characterized. Computational methods will be used to aid the interpretation of the results. Furthermore, blends with electron donors will be prepared and their structural properties characterized using such methods as X-ray scattering measurements and atomic force microscopy. These blends will also be used to build solar cells, whose efficiency then will be determined. From the data acquired the structure-properties relationship for terrylene derivatives will be elucidated. Understanding of this relationship will enable production of terrylene based acceptor materials for solar cells with improved efficiency. These new terrylene dyes and the results on the structure-properties relationship is also interesting to other fields such as material science (e.g. organic field-effect transistors) or analytical chemistry (e.g. new fluorescent dyes).
|Effective start/end date||1/10/19 → 30/09/21|