| Novel High-Performance OLED Sources (Phase II)
Investigating Organization
Universal Display Corporation
Principal Investigator(s)
Dr. Brian W. D'Andrade, bdandrade@universaldisplay.com, (609) 671-0980, x 292
Subcontractor
Princeton University
under the direction of Prof. Stephen R. Forrest
Funding Source
Small Business Innovation R&D, Phase II
Award
DOE Share: $750,000
Contract Period
6/27/03 - 6/25/05
Based on its research in phosphorescent OLED (PHOLED) technology, the project team has demonstrated OLEDs that are up to four times more power efficient than previously thought possible. In this Phase 2 program, Universal Display Corporation, Princeton University, and the University of Southern California are further pursuing two novel approaches to further increase the efficiency of broadband white light generation building on the successful feasibility studies of highly efficient white PHOLED technology demonstrated in our two previous DOE SBIR Phase 1 awards.
Novel Striped Design for White OLED Illumination Sources. Here the Team is investigating the use of PHOLEDs in a striped-pattern R-G-B configuration to demonstrate very-efficient white light generation. In this configuration, each stripe contains one of three colors, red, green and blue, or red, yellow and blue. Fabricating white OLED light sources in this manner offers a number of potential advantages and benefits. These include 1) very high power efficiency, 2) long lifetime, 3) excellent CIE and CRI, 4) full color tunability, and 5) color correction for differential aging.
Monomer-Excimer White OLED Illumination Sources While there are a number of possible approaches to produce white OLED (WOLED) lighting; USC and Princeton University recently demonstrated a novel approach using high-efficiency phosphorescent excimers. In addition to offering a power efficient approach, this approach also offers provides opportunities to reduce both the number of dopants and the number of discrete emissive layers, simplifying the device structure, the fabrication process and the resulting manufacturing costs. Our approach to reduce the number of dopants and structural heterogeneities inherent in the preceding architectures is to employ a lumophore that forms a broadly emitting state, such as an excimer or exciplex (i.e. an excited state whose wavefunction extends over two identical or dissimilar molecules, respectively).
Recently, the team has accomplished the following: New platinum functionalized random copolymers for use in solution processable white organic light emitting devices were synthesized and evaluated. A record 100% internal quantum efficiency green [CIE (0.30, 0.64)] device was fabricated. This device had EQE = 20% and a luminous efficiency = 75 cd/A at 100 cd/m2. A new record efficiency blue device has been developed. Blue [CIE (0.14, 0.21)] devices were fabricated with a luminous efficiency of 19 cd/A and an external quantum efficiency of 12% at 100cd/m2. This is a much higher efficiency than can be achieved from fluorescent emitters, and is a 60% improvement over previous blue device reports provided by UDC. Developed a model to predict the ability of an end-user to differentiate between the various colored striped lines.
In Phase 2, the team will demonstrate white OLEDs with greater than 20 lm/W efficiency at 800 cd/m2, and deliver 6” x 6” prototype lighting panels, based on tiling four 3” x 3” sub-panels. This work will then be coupled with parallel development programs focusing on improving PHOLED performances through new materials development, device optimization, lifetime improvement, and novel approaches to enhance the optical extraction efficiency. The successful completion of this Phase 2 program will significantly accelerate the use of OLED devices as commercial sources of general illumination.
Content dated 2/08 |
