A novel luminescent block copolymer (TEO-MPV), containing alternating distyrylbenzene and tri(ethylene oxide) segments, has been synthesized through a Wittig polycondensation reaction. The structure of the copolymer was verified using FT-IR, H-1 NMR, and elemental analysis. The electrochemical properties of the copolymer were evaluated and the HOMO and LUMO energy levels of the copolymer were estimated by cyclic voltammetry. Thermal analysis showed that the glass transition temperature (T-g) of the copolymer is about 85.6 degreesC, and the decomposition temperature is over 384 degreesC. The fluorescence quantum yield of TEO-MPV chloroform solution reaches 99.05%, much higher than that of other analogous polymers, ITO/TEO-MPV/Al single layer LED, ITO/PEDOT-PSS/TEO-MPV/Ca (Al) bilayer LED and a light-emitting electrochemical cell (LEC) have been successfully fabricated, respectively. The performances of the devices have demonstrated that the copolymer is a promising candidate for LEC devices. (C) 2002 Elsevier Science B.V. All rights reserved.