Highly efficient PLEDs based on poly(9,9-dioctylfluorene) and Super Yellow blend with Cs2CO3 modified cathode

Polymer light emitting diodes (PLEDs) based on the blend of 90% poly(9,9-dioctylfluorene) (F8) and 10% Super Yellow (SY) were used as the emissive layer and it exhibited high luminous efficiency up to similar to 27 cd A(-1). Hole-trapping nature native to the proposed blend system and efficient electron injection via Al/Ca/Cs2CO3 cathode was used against the conventional ITO/PEDOT:PSS anode which provided a well-balanced charge transport across the emissive layer. Thereby, the scheme maximizes the radiative recombination of these excitons within the bulk and away from the cathode. Consequently, non-radiative quenching effects at the cathode surface were avoided which resulted in ultrahigh efficiency of such devices. (C) 2015 Elsevier Ltd. All rights reserved.