Benzoquinoline-based fluoranthene derivatives as electron transport materials for solution-processed red phosphorescent organic light-emitting diodes. Issue 45 (30th May 2017) - Park, So-Ra
Abstract : A new electron transport material (ETM) with two fluoranthene and a benzoquinoline moiety was synthesized for the fabrication of solution-processed phosphorescent organic light-emitting diodes (PHOLEDs). Abstract : A new electron transport material (ETM) with two fluoranthene and a benzoquinoline moiety was synthesized for the fabrication of solution-processed phosphorescent organic light-emitting diodes (PHOLEDs). In particular, we designed a bulky structure with a large twisted angle and improved thermal stability as compared to those of the common ETMs [ e.g., 2, 2′, 2′′-(1, 3, 5-phenylene)tris(1-phenyl-1 H -benzimidazole) (TPBI)] for device stability. As a result, we found that 4-(3-(fluoranthen-3-yl)-5-(fluoranthen-4-yl)phenyl)-2-phenyl-benzo[ h ]quinoline (FRT-PBQ ) showed high glass transition temperature ( T g : ∼184 °C) and moderately high electron transport behavior despite its bulky structural moieties. Moreover, we fabricated solution-processed red PHOLEDs withFRT-PBQ, and a relatively high current efficiency and external quantum efficiency of up to 20.7 cd A −1 and 15.5%, respectively, were achieved. In addition, the device lifetime was extended by a factor of 1.7 as compared to that of the device fabricated with TPBI as a common ETM.