BROWSE
Detail
Conference Paper
Transparent white organic light emitting diodes with improved cathode transparency
Cited 1 time in 
Share 
Share
- Issue Date
- 2009-08
- Citation
- Organic Light Emitting Materials and Devices XIII (SPIE 7415), v.7415, pp.1-7
- Publisher
- SPIE
- Language
- English
- Type
- Conference Paper
- Abstract
- We have fabricated transparent white organic light emitting diode (WOLED) for lighting application based on a hybrid white OLED and a phosphorescence white OLED. For the hybrid WOLED, a blue fluorescence emitting layer (FL-EML) and green and red phosphorescence emitting layers (PH-EMLs) have been used in the device structure of ITO/hole transporting layer (HTL)/PH-EMLs/interlayer/FL- EML/ETL/LiF/Al. The balanced emissions from the FL-EML and the PH-EMLs have been obtained by using appropriate carrier (hole) trapping effects in the PH-EMLs, which resulted in external and power efficiencies of 15 % and 27 lm/W, respectively, at a luminance of 1000 cd/m2 without any out-coupling enhancement. The Commission Internationale de L'Eclairage (CIE) coordinates of this hybrid WOLED is (0.43,0.44) with color rendering index (CRI) of 80 and correlated color temperature (CCT) of 3200 K, respectively, in the bottom emission structure. Based on this hybrid WOLED, we established highly efficient transparent WOLED by introduction of a transparent cathode, and obtained over 19 lm/W of power efficiency at a total luminance of 1000 cd/m2 as well as over 60 % of transmittance at 550 nm with the conventional glass encapsulation. Moreover, when the phosphorescent white OLED was combined with a transparent cathode, the power efficiency was reached up to 24 lm/W of power efficiency at a total luminance of 1000 cd/m2. © 2009 SPIE.
- KSP Keywords
- Color rendering index, Device structure, Emission structure, Hole transporting layer, Organic light-emitting diodes(OLEDS), Power Efficiency, Red phosphorescence, Transparent cathode, Trapping effects, White organic light-emitting diodes, blue fluorescence