Novel organic sensitizers and hole transport materials for efficient solid-state photovoltaic devices

Sammanfattning: State-of-art solid-state photovoltaic devices, such as solid-state dye sensitized solar cells (ssDSSCs) and perovskite solar cells have attracted significant attention due to their high efficiency and potential low-cost manufacture. However, there are still challenges that limit the application up-scaling.. One important factor that limits the efficiency of ssDSSCs is associated with the sensitizers. In this thesis, we have developed several organic sensitizers for highly efficient and stable ssDSSCs. The compatibility between sensitizers and hole transport materials has also been investigated. Novel blue colored sensitizers have been studied with aesthetic applications in mind. By co-sensitization using two complementary sensitizing dyes, the efficiency of ssDSSCs can be increased significantly.. For both PSCs and ssDSSCs, the hole transport materials (HTMs) represent one of the crucial factors for efficient charge collection as well as future cost of manufacturing. Here, we have studied organic triphenylamine based oligomers as HTMs for both ssDSSCs and PSCs. The influence of the molecular structure of the HTM building blocks on the photovoltaic performance has been studied in detail. In order to minimizing the cost of fabrication of photovoltaic devices, we have also developed sulfur-based cross-linked polymers as HTMs to replace the well-known, expensive HTM Spiro-OMeTAD. The cross-linked polymeric sulfur material work well in both ssDSSCs and PSCs with efficiencies around 2% and 10%, respectively. These results will provides important insights for the future design of inexpensive and efficient solid state photovoltaic devices.