Efficient and color stable phosphorescent white organic light-emitting devices based on an ultra wide band-gap host

• Published in: Synthetic metals Vol. 159; no. 11; pp. 991 - 994
• Main Authors: Lee, Jonghee, Lee, Jeong-Ik, Chu, Hye Yong
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.06.2009; Elsevier
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Optoelectronic devices; Organic light-emitting diodes (OLEDs); Phosphorescent; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; White OLED; White OLED; Phosphorescent; Organic light-emitting diodes (OLEDs); Interfacial layer; Performance evaluation; Exciton; White light; Hole mobility; Quantum yield; Ultra wide band; Biphenyl; Organic light emitting diodes; Optoelectronic device; Phenanthrolines; Chromaticity; Phosphorescence; Wide band gap semiconductors; Organic electronics
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/j.synthmet.2008.12.031

We report high efficiency phosphorescent white organic light-emitting devices (WOLEDs) employing single emissive layer (EML) based on an ultra wide band-gap host. Effective exciton/charge confinement and balanced recombination within EML was achieved by employing adequate interlayer and stepwise hole-transporting layer (step HTL) system. Moreover, this step HTL system lower driving voltage of WOLEDs, therefore power efficiency was enhanced over 40%. These WOLEDs showed external quantum, and power efficiencies of 17.6%, and 37.5 lm/W at 100 cd/m 2 without outcoupling enhancements. We also found that these WOLEDs exhibited little change of color coordinate from 100 to 10,000 cd/m 2.