Dramatic enhancement of photo-oxidation stability of a conjugated polymer in blends with organic acceptor

Photo-oxidation of a prototype conjugated polymer poly[2-methoxy-5-(2(')-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) in blended films with 2,4,7-trinitrofluorenone (TNF) is drastically suppressed upon exposure to green laser radiation under ambient conditions that was observed by using Fourier transform infrared spectroscopy. By increasing the TNF concentration in MEH-PPV, we have found that the photo-oxidation rate and the photoluminescence intensity drop together in a correlated way by three orders of magnitude. We suggest that triplet exciton formation in the MEH-PPV/TNF blends is deeply suppressed blocking the photo-oxidation. These findings may open a way to intrinsically photostable conjugated polymer materials for photonic and photoelectric applications. (c) 2008 American Institute of Physics.