Low-threshold amplified spontaneous emission in blends of conjugated polymers

Low thresholds (similar to 500W/cm(2)) for amplified spontaneous emission ( ASE) are reported in films of soluble poly(paraphenylene vinylene)-based co njugated polymer blends. Efficient Forster energy transfer from the absorbi ng host polymer to the emitting guest polymer is observed. Emission in the blends originates predominantly from the guest polymer. The large spectral shift between the absorption and emission wavelengths lowers the self-absor ption losses and results in low ASE thresholds. Initial results show an enh ancement in photoluminescence quantum efficiency of the blends. (C) 1998 Am erican Institute of Physics. [S0003-6951(98)01550-2].