Light-Emitting Conjugated Polymers in Optical Microcavities

We studied the luminescence of microcavities consisting of a single-layer of poly(para-phenylenevinylene), PPV, sandwiched between a dielectric mirror coated with a conducting indium-tin oxide layer and a semi-transparent metal electrode. Compared with a device without cavity structure, the emission is spectrally and spatially narrowed, and the forward emission intensity enhanced. The Full Width at Half Maximum of the modes is about 4 nm in photoluminescence and we measure an enhancement of intensity in the forward direction of more than an order of magnitude. The PL efficiencies and lifetimes on a sub-ns time scale show only minor alterations with respect to PPV on glass.