The Effect of Inorganic/Organic Hybrid Quantum-Well Structure on Efficient White Organic Light Emitting Devices
In this study, the effect of MQW structures adopting inorganic material (sodium fluoride) has been demonstrated. Brightness, current efficiency was significantly enhanced with a NaF/NPB MQW structure being inserted. The admittance spectroscopy was measured to explain the different mechanism of reducing hole between organic/organic inorganic/organic MQW
Organic light-emitting diodes with improved hole-electron balance by using copper phthalocyanine/aromatic diamine multiple quantum wells
Organic light-emitting diodes (OLEDs) with multiple-quantum-well structures, which consist of copper phthalocyanine and N,N′-bis-(1-naphthyl)-N,N′-diphenyl-1,1′ biphenyl 4, 4′-diamine, have been fabricated. The effect of the MQW structure upon the performance of OLEDs with tris(8-hydroxyquinoline) aluminum as the emitting material has been investigated. Compared with the luminous efficiency of the conventional diode with the MQW number of 0, that of the diode with the MQW number of 4 has been sharply increased up to 10.8 cd/A. Such an improvement in the device performance was attributed to the improved hole-electron balance, which can be further attributed to the introduction of the MQW structure.
Highly efficient white organic light-emitting diodes with single small molecular emitting material
We demonstrate a highly efficient white organic light emitting device with fluorescent small molecule 4,4′-bis(9-(1-naphthyl)anthracene-10-yl)biphenyl (BUBH-3). With a simple device architecture of indium tin oxide/tris 4,4′,4″-tris-N-naphthyl-N-phenylamino-triphenylamine (60nm)∕N,N′-bis-(1–naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine (10nm)/BUBH-3 (45nm)∕Alq3 (15nm)∕LiF (1nm)∕Al (150nm), a white light with CIEx,y color of (0.31,0.36) was generated. The device achieved one of the best single-emitting-material electroluminescence performance of white organic light-emitting devices with efficiencies of 7.0cd∕A and 3.17lm∕W at 6.9V.