Synthesis and electro-optical properties of polythiophene derivatives for electroluminescence display

Abstract A new series of light emitting polymers composed of thiophene repeating units were synthesized and characterized by oxidative polymerization. Introduction of alkyloxyphenyl substitutent into the 3-position of the thiophene unit not only influences solubility but also controls the emission colors and electro-optical properties. Chemical structures of the resulting polymers were confirmed by UV–visible, 1H- and 13C-NMR spectra. The resulting polymers were soluble in common organic solvents and could be spin-cast onto ITO glass substrate to obtain optical thin films without defects. The turn-on voltage of the polymers were about 4.5–6.5 V and emitted a red color on forward bias.