Abstract
Fluorescent copolymers based on 3,4-diphenylmaleimide-thiophene-fluorene triad were newly synthesized and characterized. The copolymers exhibited orange-red fluorescence (λmaxem in the range of 598-620 nm) with fluorescence quantum yields of 32-37% in solution and of 13-22% in solid film. Polymer light-emitting diodes with simple device structure of ITO/PDOT:PSS/copolymers/LiF/Al, where PEDOT:PSS is (poly-ethylenedioxythiophene) :poly(styrene sulfonate), were preliminarily fabricated and tested. Similar color to solution photoluminescence, the devices showed orange-red electroluminescence with a maximum electroluminance of 2020 cd/m 2 and peak efficiency of 1.25 cd/A. © 2005 Elsevier B.V. All rights reserved.