Light sources with low color temperature (CT) are essential for their markedly less suppression effect on the secretion of melatonin, and high power efficiency is crucial for energy-saving. To provide visual comfort, the light source should also have a reasonably high color rendering index (CRI). In this report, we demonstrate the design and fabrication of low CT and high efficiency organic light-emitting diodes. The best resultant device exhibits a CT of 1,880 K, much lower than that of incandescent bulbs (2,000-2,500 K) and even as low as that of candles, (1,800-2,000 K), a beyond theoretical limit external quantum efficiency 22.7 %, and 36.0 lm/W at 100 cd/m ². The high efficiency of the proposed device may be attributed to its interlayer, which helps effectively distribute the entering carriers into the available recombination zones.

Date Published: 17 December 2011
PDF: 9 pages
Proc. SPIE 8312, Display, Solid-State Lighting, Photovoltaics, and Optoelectronics in Energy III, 83120D (17 December 2011); doi: 10.1117/12.902714

Published in SPIE Proceedings Vol. 8312:
Display, Solid-State Lighting, Photovoltaics, and Optoelectronics in Energy III
Min Gu, Editor(s)