Novel, Active Layer Nanostructures for White Light Emitting Diodes (LEDS)

75630-The most efficient solid-state white lights developed so far typically use a bright blue light emitting diode. The diode is used not only as a blue source, but also for the simultaneous optical excitement of an inorganic downconverter, which converts a fraction of the blue light to yellow. When the yellow light is mixed with the remaining blue, it is perceived by the human eye as white. However, the energy efficiency of such a ¿white light emitting diode¿ is limited because the photonic downconversion process suffers from a fundamental energy loss as the higher energy blue photons are converted to yellow. This project will develop technology for creating white light by mixing different color photons from distinct electrically pumped nanostructured active layers. The nanostructured active layers will be optimized to produce the most efficient energy conversion and white light quality. By eliminating the optical downconversion loss, the broadband emission is potentially more efficient. In Phase I, light emitting device tests structures will be fabricated, and performance will be compared to commercial packaged white solid-state lights. Commercial Applications and Other Benefits as described by the awardee: Custom colored lighting technology has the potential to replace a large percentage of inefficient incandescent lighting with energy efficient illumination, resulting in devices with previously unattainable colors and efficiencies. Lighting consumers (industrial, residential, retail, commercial) will be able to choose custom lighting colors to accent mood, style, or safety.