A new bipolar conjugated polyfluorene copolymer with triphenylamine and cyanophenylfluorene as side chains poly{[9 9 di(triphenylamine)fluorene] [9 9 dihexyl fluorene] [2 7 bis(4' cyanophenyl) 9 9' spirobifluorene]} (PTHCF) was synthe sized for studying the polymer backbone emission Its absolute weight average molecular weight was determined as 485 x 10(4) by using gel permeation chromatography with a multiangle light scattering detector In contrast to the electronic absorp non spectrum in dilute solution the absorbance of PTHCF in thin film was slightly blue shifted By comparison of the solu tion and thin film photoluminescence (PL) spectra, a red shift of Delta/ = 8-9 nm was observed in the thin film PL spectrum The HOMO and LUMO energy levels of the resulting polymer were electrochemically estimated as -5 68 and -2 80 eV respectively Under the electric field intensity of 48 x 10(5) V cm(-1) the obtained hole and electron mobilities were 2 41 x 10(-4) and 1 40 x 10(-4) cm(2) V-1 s(-1) respectively An electro luminescence device with configuration of ITO/PEDOT PSS/PTHCF70%+PBD30%/CsF/Ca/Al exhibited a deep blue emission as a result of excitons formed by the charges migrating along the full fluorene main chain The incorporation of the bipolar side chains into the polymer structure prevented the intermolecular interaction of the fluorene moieties balance charge injection/transport and thereby improve the polymer backbone emis sion (C) 2010 Wiley Periodicals Inc J Polym Sci Part A Polym Chem 48 5930-5937 2010