Novel Low-Cost Technology for Solid State Lighting

73106-In the United States, the amount of electricity used annually for lighting residential and commercial buildings is equal to approximately 20% of the total power generated. Widespread use of white LEDs would reduce the overall electrical demand for lighting by 50%. At this time, the major hurdle for solid-state lighting is the high cost of GaN-based LED production technology. This project will develop a novel epitaxial technology with substantially reduced process cost for the fabrication of group-III nitride epitaxial structures for white LEDs. This novel technology is based on hydride vapor phase epitaxy (HVPE), a low-cost method for fabricating thick quasi-bulk GaN materials, GaN-on-sapphire, and AlN-on-sapphire templates used as substrates for device fabrication. Phase I demonstrated that the technology could be used to cost-effectively fabricate AlGaN-based structures and package violet, ultraviolet, and white LED lamps for lighting application. White LED lamps were assembled by packaging the violet LEDs with a white light conversion phosphor blend. Phase II will focus develop cost effective HVPE manufacturing technology for multi-wafer, Al(In)GaN-based structures production. The efficiencies of violet, UV and white LED lamps will be improved, with brightnesses up to 100 Lm/W anticipated. Commercial Applications and Other Benefits as described by awardee: The low cost and high throughput of HVPE should dramatically lower overall device cost and enhance device and component development. White-light LEDs are needed for wide variety of applications including commercial, residential and building lighting, task lighting, aviation, and hazard indicators. UV LEDs are needed for biochemical agent detection and/or eradication systems. Blue-violet LEDs already have found a market in full-color displays, back lighting, and indicator lights.