High Brightness LEDs based on the (A1, Ga,In)N Materials System

116 High Brightness LEDs based on the (Al, Ga,In)N Materials System--Advanced Technology Materials, Inc., 7 Commerce Drive, Danbury, CT 06810-4131; Dr. Karim Boutros, Principal Investigator Dr. Duncan W. Brown, Business Official DOE Grant No. DE-FG02-97ER82319 Amount: $75,000 Based on a combination of physical, electronic and optical properties, the semiconductor materials system (aluminum, gallium, indium nitride) has emerged over the last two years as the clear choice for fabricating optical devices producing green, blue, and ultra-violet light. These materials are very attractive for use with advanced sensors for use in detecting and monitoring, for instance, the illegal diversion of nuclear weapons materials. However the widespread use of nitride-based devices is currently limited by fabrication yield due to the lack of a suitable starting substrate material. The choice of the starting substrate is crucial for insuring the quality of subsequent device layers. In this project a new wafer substrate for the nitride-based Light-Emitting Devices (LEDs) will be used to eliminate a major source of device defects (and consequently yield loss). This substrate consists of a low defect density gallium nitride prepared by hydride vapor phase epitaxy. In Phase I the material synthesis technology of key elements of LEDs will be developed on the gallium nitride substrates. A functional device having blue light emission will be demonstrated at the end of Phase I. The demonstration of high brightness blue and green LEDs will be the goal of Phase II. Commercial Applications and Other Benefits as described by the awardee: High brightness blue and green LEDs are essential components in the design of full-color displays, high density data storage systems, and spectroscopic analysis systems. The LEDs are also potential candidates for replacing incandescent lamps (e.g., traffic signals) because of their low power consumption and long life. The gallium nitride substrate proposed for use in this program could potentially become the substrate of choice for all nitride-based devices. Finally the device technology developed in Phase I and Phase II would be directly applicable to the fabrication of blue semiconductor lasers._