Electroluminescence devices with poly(paraphenylene) and derivatives as the active material

Conjugated polymers are promising materials for electro-luminescence devices. We have shown recently that blue light emission can be achieved, when poly(paraphenylene) is used as the active material in a Schottky-like device. The maximum of the electroluminescence emission is observed around 470 nm. Poly(paraphenylene), PPP is stable up to high temperatures and its electronic structure can be tailored by influencing the conjugation length and the tilt angle of consecutive phenyl rings. PPP was synthesized by soluble precursor polymers and as a soluble PPP ladder type polymer. Via the tailoring of the electronic structure, electroluminescence devices with different colors can be fabricated. In contrast to the blue emission of the PPP prepared by a precursor route, the PPP ladder polymer, which has planar structure exhibits a strong yellow-green emission. We report on the physical properties of the different devices, concerning the device structure and the active materials.