Poly(p-phenylene)-based materials for light-emitting diodes : Electroluminescence and photo-oxidation

A series of alkoxy-substituted poly (p-phenylene) derivatives were synthesized using the well-known Suzuki reaction. The present polymers have strong UV-visible absorption bands around 340450 nm and their PL spectra give a highest peak around 430550 nm in the blue-green region. In this paper, π -conjugated chain lengths were molecularly regulated, leading to the color tune from PPP-based materials. Their EL spectra in a single-layered device show a highest peak around 430550 nm in the blue-green region with the operating voltage of lower than 7V. Also, the photo-oxidation for poly(p-phenylene) derivatives in air was studied.