We synthesized the new copolymer, which was composed of dialkoxy naphthalene, N-alkylcarbazole, and fluorine, by Suzuki coupling reaction. The resulting copolymer was soluble in common organic solvents and showed the weight-average molecular weight (MW) of 288,000 with a polydispersity index of 2.56. Cyclic voltammetry and UV-vis study revealed that the HOMO energy level and optical band gap of copolymer was 5.66 and 3.03 eV, respectively. The ITO/PEDOT/polymer/LiF/Al device emits bright deep blue light with a maximum peak around 422 nm. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 43-48, 2011