The generation of energy is one of the most important scientific and technological challenges of the 21st century. Solar energy is one of the fastest growing renewable energy sources: it does not produce pollutants or harmful byproducts and is free of emissions. In the search for low cost energy alternatives, thin film photovoltaics based on organic materials have attracted a great deal of attention over the last two decades due to some key advantages, as low weight, flexibility, and significantly lower manufacturing costs compared to conventional inorganic technologies. Among organic solar cells, dye-sensitized solar cells (DSSCs) have the most promising future. The main objective of this project is to develop dye-sensitized solar cells (DSSCs) using novel, molecularly engineered, phenoxazine (POZ)- or phenothiazine (PTZ)-based sensitizers able to complete or substitute the sensitizer structures currently in use.