Research Highlights 2007-2008

 

Photo of what looks like a transparent three-dimensional pyramid containing compartments with the top sliced off, the top remaining part being a white rectangle.  There appears to be a person's finger above it.

Record Efficacy for White OLED

Universal Display Corporation has successfully demonstrated an all phosphorescent white organic light emitting diode (WOLED™) with a record power efficacy of 45 lm/W at 1,000 cd/m2. This high-efficacy device was enabled by lowering the device operating voltage, increasing the outcoupling efficiency, and incorporating highly efficient phosphorescent emitters. (June 2007) Learn more.

Photo of a bright purple square with a purple frame containing a bright white light in the center.

High-Efficiency Nitride-Based Photonic Crystal Light Sources

The University of California Santa Barbara is maximizing the efficiency of white LEDs by enhancing the external quantum efficiency using photonic crystals to extract light that would normally be confined in a conventional structure. (January 2008). Learn more.

Photo of a microscope image of a mini deep green LED. Image shows part of a circle with intersecting green bands, green and black shapes, and a smaller glowing circle at the center.

Increasing Efficiency of Green LEDs

DOE-funded research at Rensselaer Polytechnic Institute (RPI) has shown the importance of both the epitaxial structure and the substrate material in improving green light efficiency. The RPI team is working on non-polar epitaxial multi-quantum well LEDs on Gallium Nitride substrates that produce deep green light directly. (January 2008) Learn more.

Image of two people standing in a modernistic room with walls and floor composed of a grid of transparent glass rectangles, and glowing rectangles hanging from the ceiling.

Record White OLED Performance Exceeds 100 lm/W

Universal Display Corporation has successfully demonstrated a record-breaking white OLED with a power efficacy of 102 lm/W at 1000 cd/m2 using its proprietary, high-efficiency phosphorescent OLED technology. (June 2008) Learn more.

Photo of a dark blue square on a circuit board, with four tiny light blue lights lit within the square.  Wires connect on both the right and left.

Achieving Record Efficiency Blue OLEDs by Controlling the Charge Balance

University of Florida researchers have demonstrated a blue phosphorescent organic light-emitting diode (OLED) with a peak power efficiency of 50 lm/W and an external quantum efficiency exceeding 20 percent at a luminance of 1,000 cd/m2, using no external light extraction techniques. This accomplishment is believed to be the world record in blue OLED efficiency. (September 2008) Learn more.

Photo of an LED: a bright semi-globe atop a square substrate.

New Benchmarks for LED Efficacy and Brightness

Cree has successfully created a cool white LED prototype that delivers 107 lm/W at 350mA. This achievement builds on the Cree EZBright® LED chip platform, developed in part with prior funding support from DOE. (September 2008) Learn more.

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