Optical mode structure in a single-layer polymer microcavity

We report investigations of the electroluminescence (EL) and photoluminescence (PL) of a microcavity which is formed by 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 aluminium electrode. Compared with a device without cavity structure, the spectral and spatial emission distributions are significantly narrowed, and the forward emission intensity is enhanced. We measure a spectral linewidth (FWHM) of the cavity modes of 10 nm in PL and 20 nm in EL.