Photonic crystals have received an increasing amount of interest for use as light extractors in light-emitting diodes (LEDs), but their implementation on the surface of LEDs has thus far produced little improvement in extraction efficiency.
Researchers at the University of California, Santa Barbara have developed a gallium nitride (GaN) LED design using embedded air-gap photonic crystals within the device — an implementation allowing control over the direction of light emission and increased efficiency. These LEDs exhibit highly directional light emission and have achieved extraction efficiencies of up to 94%. They are ideal for use in applications requiring high-efficiency and/or high-brightness LEDs, such as solid-state lighting and automobile headlights.
This technology is available for licensing.