SBIR Phase I: Efficient Light Out Coupling from AlGaN Light Emitting Diodes

Phosphortech Corporation, Kennesaw GA

Investigators

Abstract

This Small Business Innovation Research (SBIR) Phase I project propose to develop new device concepts and manufacturing techniques to greatly increase light extraction efficiency. Current solid state devices suffer from poor light extraction efficiencies (<10%) as the result of the mismatch in the index of refraction between the light emitting diode (LED) material and epoxy/air interface. The new concept maximizes output coupling through detailed control of the optical properties (refractive index, scattering, absorption, etc.) of the materials surrounding the LED die. This will be accomplished through the use of a nanotechnology based material deposition technique suitable for high volume production of LEDs and LED arrays. The commercial application of this project is in energy efficient replacements for incandescent and fluorescent lighting. These techniques have applicability to all LED light sources. Thus, any current application, such as lighting in portable electronics, automobiles, traffic signaling, etc., will immediately benefit from the increased efficiency. Increased efficiency will also open new markets where traditional light sources currently dominate and will lead to significantly reduced energy requirements, lower levels of pollution, reduced toxic waste (e.g., Hg from fluorescent lamps) and a reduced dependence on foreign oil suppliers.