Charge carrier generation and exciton quenching at M3EH-PPV/small-molecule and M3EH-PPV/oxide interfaces

The need for efficient exciton dissociation is one of the most important factors limiting improved efficiencies in organic photovoltaic devices. Using luminescence as a probe, we studied the quenching of excitons in semiconducting polymers for a variety of quenching materials, including transparent conducting oxides (TCOs) and small molecule perylene diimide thin films. Perylene benzimidazole (PBI) is shown to be the best quencher of those studied. This result is consistent with the improved conversion efficiencies demonstrated when this material is used in a polymer bilayer photovoltaic device.