Probing the nanoscale phase separation in binary photovoltaic blends of poly(3-hexylthiophene) and methanofullerene by energy transfer
The generation of charge carriers in organic photovoltaic devices requires exciton diffusion to an interface of electron donor and acceptor materials, where charge separation occurs. We report a time resolved study of fluorescence quenching in films of poly(3-hexylthiophene) containing a range of fractions of the electron acceptor [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). We show that energy transfer from P3HT to PCBM helps to bring excitons to the interface, where they dissociate into charge carriers. Fluorescence quenching in blends with < or = 50 wt% of PCBM is controlled by exciton diffusion in P3HT. This allows us to estimate the average size of PCBM domains to be about 9 nm in the 1:1 blend. The implications for polymer solar cells are discussed.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.