| Abstract
| - A series of copolymers, poly{9,9-bis(2‘-ethylhexyl)fluorene-2,7-diyl-co-2,5-bis(2-thienyl-1-cyanovinyl)-1-(2‘-ethylhexyloxy)-4-methoxybenzene-5‘ ‘,5‘ ‘‘-diyl} (PFTCVB), were synthesized from themonomers 2,7-dibromo-9,9-bis(2‘-ethylhexyl)fluorene and 2,5-bis(2-(5‘-bromothienyl)-1-cyanovinyl)-1-(2‘ ‘-ethylhexyloxy)-4-methoxybenzene (BTCVB) through the Ni(0)-mediated polymerization. The copolymerswere characterized using FT-IR spectroscopy, UV−vis spectroscopy, TGA, photoluminescence (PL) andelectroluminescence (EL) spectroscopy, elemental analysis, and molecular weight studies. The synthesizedcopolymers showed an absorption maximum at about 380 nm, and between 425 and 600 nm the absorptionincreased with increasing fraction of thiophene-containing monomer 4 (BTCVB). In PL, the emissionmaxima of the copolymers were red-shifted as the fraction of BTCVB increases, despite the copolymersshowing little variation in UV−vis absorption characteristics. Light-emitting devices were fabricated inan ITO (indium−tin oxide)/PEDOT/polymer/LiF/Al configuration. The EL spectra showed similar emissionsto the PL results, and the copolymer containing 15 mol % of BTCVB showed bright-red emission.
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