Emory Krall

Phosphorescent organic light-emitting diodes for high-efficacy long-lifetime solid-state lighting

We report data for a pair of singlestack all-phosphorescent 15 × 15 cm 2 organic light emitting-diode (OLED) light panels with high efficacy, long lifetime, and very low operating temperature: Panel 1 has 62 lm∕W efficacy, CRI ¼ 81 and lifetime to LT70 ¼ 18;000 h at 1000 cd∕m 2 , while Panel 2 has 58 lm∕W efficacy, CRI ¼ 82 and lifetime to LT70 ¼ 30;000 h at 1000 cd∕m 2 . Operating at a higher luminance of 3000 cd∕m 2 , Panel 2 has 49 lm∕W efficacy with lifetime to LT70 ¼ 4000 h. Excellent panel lifetime is enabled by a stable light blue phosphorescent materials system. Panel temperatures are within 10°C of ambient temperature at 3000 cd∕m 2 . Panel 2 was further used as a building block to demonstrate an all-phosphorescent OLED luminaire for under-cabinet lighting applications. Operating at approximately 3000 cd∕m 2 , theluminairedelivers570lmwith52 lm∕Wtotalsystemefficacy,CRI ¼ 86andCCT ¼ 2940 K.© 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). (DOI: 10.1117/1.JPE.2.021205)