High Efficiency ZnO-Based LEDs on Conductive ZnO Substrates for General Illumination

76064-General lighting applications use about 22% of total U.S. electric energy production. The potential high efficiency of white light LEDs offers the promise of significantly reducing this energy usage, but first, higher efficiency and lower costs will be required. In this project, high efficiency, white light LEDs will be fabricated from alloys of ZnO placed on conductive ZnO substrates. Phosphors will be used to convert the nearly monochromatic blue or near UV light of the LED to white light. The inherent, high luminous efficiency of ZnO will result in increased efficiency and lower cost than current technology. In Phase I, a single quantum well LED will be constructed using a CdZnO alloy as the quantum well and MgZnO as the barriers. The ZnO-based LED structures will be fabricated and characterized, and the resulting data will be used to project the efficiency of an optimized LED device based on these compounds. Phosphors for the conversion to white light will be selected, and their impact on the overall efficiency will be evaluated. Commercial Applications and Other Benefits as described by the awardee: The technology should result in high efficiency, low cost, white light LEDs for general illumination; in high brightness blue and ultra violet LEDs for application in displays and backlighting; and in high efficiency diode lasers used in the high density optical storage (DVDs, etc.) and in printing (i.e., direct computer writing to printing plates).