OPTICAL-EMISSION FROM CONFINED POLY(THIOPHENE) CHAINS

We discuss the stages of the luminescence processes in substituted and soluble poly(thiophenes), using results from determinations of absolu te quantum yields of photoluminescence, fast pump-probe experiments an d microcavity devices. Enhancement of the quantum yield of photolumine scence, with poly(thiophenes) in the solid state, call be obtained by dispersing the conjugated chain in a molecularly dispersed polymer ble nd, or by adding side chains designed for forcing the conjugated main chains apart. At the wavelength of stimulated emission, we observe a n arrow bandwidth emission in the high-Q one-dimensional microcavity dev ices prepared by sandwiching two dielectric mirrors around a thin poly mer film, A strong enhancement of the power efficiency is observed at a pump power of 1 mu W/cm(2), but does not conclusively show lasing ch aracteristics. (C) 1998 Elsevier Science B.V.