High dielectric constant donors and acceptors for organic photovoltaics

Organic solar cells bear the potential to develop a long-term technology that is environmentally clean and economically promising for large-scale power generation. Thanks to higher absorption coefficient, organic materials can be incorporated as thin films in organic photovoltaic (OPV) devices leading to a 10-fold reduction in the consumption of the material as compared to their inorganic counterparts. The dielectric constant is an essential parameter for efficient solar cells. Current organic materials for organic photovoltaics have low dielectric constants in the range of 2 to 4. This imposes an efficiency limiting factor in changing light into free charge carriers making them not competitive to their high dielectric inorganic counterparts, like Si which has a dielectric constant of ~12. It is feasible to design more efficient organic solar cells by introducing high-dielectric-constant organic donors and/or acceptors leading to next generation OPV. With this project we want to characterize the performance of organic semiconductors with high dielectric constant for photovoltaic applications. We focus the research on the PEO-PPV and PTEG-1, these materials have triethylene glycol (TEG) side chains which increase their dielectric constant. In previous studies has been seen that PEO-PPV has a dielectric constant of 6 at low frequency ranges (f