Combining Fluorescence and Phosphorescence to Achieve Very Long Lifetime and Efficient White OLEDs (Final Technical Report)
- Univ. of Southern California, Los Angeles, CA (United States); University of Southern California
- Univ. of Michigan, Ann Arbor, MI (United States)
The objective of our project was to develop a high efficiency, long lived WOLED using a hybrid approach to harvesting singlet and triplet excitons, as described above. WE met out GONOGO metric at the end of year one, achieving an efficiency of nearly 50 lm/W for high quality white light emission. We faced an unforeseen problem in achieving this high efficiency level at high brightness. Our hybrid devices showed a significant roll off in device efficiency as the current is raised, such that our efficiency dropped to ca. 10 lm/W at 1000 nits. This roll off precluded us form achieving our send year targets with regards to efficiency at high brightness and long device lifetime. We spent the majority of our efforts in year two trying to decrease or eliminate this efficiency roll off, but this roll off prevented us from reaching our end of program target of high efficiency at high brightness with long device lifetime. Toward the end of the sixth quarter of the program we began to investigate a new approach, which involved a tandem WOLED, with a hybrid blue/red OLED stacked on a phosphorescent green OLED. The resultant emission from the stack will be white and the tandem structure relaxes the constraints on the materials, which we believe is key issue in the high roll off in efficiency.
- Research Organization:
- Univ. of Southern California, Los Angeles, CA (United States); Univ. of Michigan, Ann Arbor, MI (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE)
- DOE Contract Number:
- EE0008244
- OSTI ID:
- 1797354
- Report Number(s):
- DOE-USC--8244
- Country of Publication:
- United States
- Language:
- English
Similar Records
Printed Anodes and Internal Light Extraction Layers on Flexible Glass to Create Cost Effective and High Efficacy Bendable OLED Lighting Panels
High Brightness OLED Lighting
Technical Report
·
Mon Apr 15 00:00:00 EDT 2019
·
OSTI ID:1507567
High Brightness OLED Lighting
Conference
·
Wed May 25 00:00:00 EDT 2016
·
OSTI ID:1342752