Multicolor electroluminescence and stimulated emission of conjugated polymers and oligomers

We present efficient blue electroluminescence devices based on pure soluble poly(paraphenylene) polymers and poly(phenylene) oligomers. Highly efficient green and red emission light is produced with a new color conversion technique by pumping fluorescent dye layers with blue organic light-emitting diodes. The high intrachain order of the laddertype poly(paraphenylene) allows us to observe stimulated emission in the blue-green spectral regions, which does not compete with dissipative processes, like in other conjugated polymers. We discuss the state of the art situation to realize an optically pumped homopolymer solid state laser.