Enhanced resonance energy transfer from PVK to MEH-PPV in nanoparticles.

Organic semiconductor nanoparticles were prepared from poly(N-vinylcarbazole) (PVK), poly(2-methoxy-5-(2(')-ethyl-hexyloxy)-p-phenylene vinylene) (MEH-PPV) and their blend solution via a reprecipitation method, respectively. A wide photoluminescence band centred at 430 nm has been found in the PVK nanoparticles, which is obviously red-shifted by comparison with the PVK film. The red-shifted emission from the PVK nanoparticles has a good spectral superposition with the absorption of the MEH-PPV nanoparticles. However, the spectral superposition is very poor between the two polymers in the composite films. The markedly enhanced emission from MEH-PPV is experimentally observed in the composite polymer nanoparticles and attributed to Förster energy transfer from PVK to MEH-PPV for excitation at the absorption maximum of PVK.