Multilayer fluorescent polymer light emitting diode with low voltage and high efficiency
Résumé
This study reports highly efficient green multilayer polymer light-emitting diodes (PLEDs). The fluorescent polymer is poly[(9,9-dioctyl-2,7-divinylene-fluorenylene)-alt-co-{2-methoxy-5-(2-ethylhexyloxy)- 1,4-phenylene}] end capped with dimethylphenyl (ADS108GE). This emissive polymer has been found to behave as an electron transport emitter. A poly(N-vinylcarbazole) (PVK) layer has been introduced as both hole transporting layer/electron blocking layer. Thicknesses of both ADS108GE and PVK layers have been optimized. 3.1 lm/W have been achieved which corresponds to an improvement by a factor 2 comparing to devices without PVK. Luminances as high as 25 000 Cd/m2 at low operating voltage are reported.