Optically detected magnetic resonance studies of nanostructured PPV-composites

We used the spectroscopic technique of photoluminescence detected magnetic resonance (PLDMR) to monitor the dynamics of singlet excitons as well as po larons of isolated poly(p-phenylenevinylene) (PPV) chains incorporated into a self-assembled matrix, ordered at a nanometer scale, and compare it with the results obtained for bulk PPV. The isolation of the PPV chains in the inorganic matrix which is of hexagonal structure is confirmed by a blue shi ft of the photoluminescence (PL) spectrum and the increase of the PL quantu m yield. The effect on the photo physical properties due to the isolation o f the polymer chains is further proved by the difference in the PLDMR linew idth and the observation of a strong difference in the exponent in power-la w dependence of Delta PL/PL on the laser power. (C) 1999 Elsevier Science B .V. All rights reserved.