Key points are not available for this paper at this time.
A promising approach to improve the processability of semiconducting polymers is their incorporation into host matrices formed by conventional polymers such as polyethylene (PE) or polystyrene (PS). We have characterized the linear optical properties of several guest–host systems by absorption and luminescence measurements and probed the excited states by photoinduced absorption measurements (PIA) and light induced electron spin resonance (LESR). The interesting photophysics of conjugated polymer/fullerene donor–acceptor system, showing an ultrafast photoinduced electron transfer and a metastable charge separation in the pristine state, has been investigated in such composites where the photoactive components are further embedded into a conventional polymer matrix. The composition of the blend and the relative concentration of the components are found to strongly influence the photoinduced interaction between the conjugated polymer and the fullerenes (C60 and functionalized fullerenes). Photoinduced electron transfer between a soluble polyphenylenevinylene (PPV) derivative and C60 is observed in a system with PS as host when the concentration of the both electroactive components is 33%. In diluted composites with PS as matrix we find strong luminescence quenching of the PPV derivative but no electron transfer upon adding C60. Dominant photoexcitations in these PS systems are triplet states as follows from intensity dependencies and lifetime measurements. In diluted systems with PE as matrix neither charge transfer nor luminescence quenching has been observed.
Brabec et al. (Wed,) studied this question.