LED Device Structures with Minimized Light Re-Absorption

Brief Description

A III-nitride light emitting diode (LED), in which light can be extracted from two surfaces of the LED before entering a shaped optical element and subsequently being extracted to air.

Background

The LED structure affects how much light is emitted. In order to increase the light output power from the front side of the LED, conventional LEDs are typically equipped with a mirror placed on the backside of the substrate, or a mirror coating on the lead frame. However, this reflected light is re-absorbed by the active region of the LED, because the photon energy of emitted light is almost same as the band-gap energy of the light emitting materials. Due to this re-absorption of the emitted light by the active region, the net output power or the efficiency of the LED is decreased.  Therefore, to achieve highly output power efficiency of the LED, device structures in which re-absorption of the light is minimized are desirable.

Description

Researchers at the University of California, Santa Barbara have developed a III-nitride light emitting diode (LED), in which light can be extracted from two surfaces of the LED before entering a shaped optical element and subsequently being extracted to air. This technology minimizes the light re-absorption at the LED active region by eliminating light reflection at the p-type side surface of the LED chip.

Advantages

• Reduces light reflections 

• Increased  light extraction efficiency

Applications

This technology is available for licensing.

Patent Status