Two novel copolymers of polyfluorenes/poly(p-phenylenevinylene)s copolymers with p-tert-butyl-phenylenemethylene groups in the C-9 position of alternating fluorene unit, poly[1,4-(2,5-dibutyloxyl)-phenylenevinylene-alt-9-(p-tert-butyl-phenyle nemethylene)fluorene] and poly[1,4-(2,5-dioctyloxyl)-phenylenevinylene-alt-9-(p-tert-butyl-phenyle nemethylene)fluorine], have been synthesized via the Heck polycondensation reaction. The synthesized polymers were characterized by FTIR, NMR, DSC, TGA, UV-vis, and PL spectra. The polymers showed high glass transition temperatures and good thermal stability. A polymer light-emitting diode with the configuration ITO/PEDOT:PSS/P2/Ca/Al has been fabricated. The device emitted a yellow light with a peak wavelength of 578 nm similar to the PL spectra of the copolymer film. A maximal luminance of 534 cd/m(2) was obtained at a driving voltage of 24.5 V. (c) 2006 Wiley Periodicals, Inc.