EMISSION ENHANCEMENT IN SINGLE-LAYER CONJUGATED POLYMER MICROCAVITIES

We have studied the luminescence properties of microcavities which are formed by a single layer of poly(para-phenylenevinylene) sandwiched b etween a dielectric mirror coated with a conducting indium tin oxide l ayer and a semitransparent metal electrode. Compared with a device wit hout cavity structure, the spectral and spatial emission are significa ntly narrowed, and the forward emission intensity is enhanced. We meas ure a spectral linewidth (full width at half maximum) of the cavity mo des of about 4 nm in photoluminescence and 20 nm in electroluminescenc e and an enhancement of luminescence intensity in the forward directio n of more than an order of magnitude. The implications of the narrowin g of the emission and possible transfer mechanisms for excitation ener gy are discussed. (C) 1996 American Institute of Physics.