Composite and Blends of PFD and MEH-PPV Conjugated Polymer Nanoparticles: Combined Optical Properties and Quantum Yield Increase by FRET

More importantly, our results show that in CPNs fabricated with both polymers mixed prior to the formation, PFD can transfer energy by Förster resonance energy transfer (FRET) to MEH-PPV. The FRET efficiency is highly dependent on the concentration and ratio of the polymers, reaching values of efficiency above 90% for distances of the order of 4 nm. This energy transfer in blend nanoparticle samples (CPN/PFD:MEH-PPV) resulted in an overall enhancement of the photoluminescence quantum yield of the hybrid nanoparticles, reaching values up to two times higher than those measured for pure CPN/MEH-PPV nanoparticles.

These findings show that the donor–acceptor ratio controls energy-transfer efficiency by regulating the fraction of interacting donor–acceptor pairs in hybrid conjugated polymer nanoparticles, enabling applications in luminescent nanostructures, sensing, and photonic devices.