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| Rensselaer researchers aim to close ’green gap’ in LED technology A team of researchers from Rensselaer Polytechnic Institute has received $1.8 million in federal funding to improve the energy efficiency of green light-emitting diodes (LEDs). As part of the U.S. Department of Energy's (DOE) Solid-State Lighting Program, the team aims to close the "green gap" in LED technology by doubling or tripling the power output of green LEDs in three years, an advance that ultimately could lead to the replacement of incandescent and fluorescent lamps in general illumination applications. The team of scientists and engineers will meet the aggressive performance targets laid out in DOE's solid-state lighting accelerated roadmap, which calls for the development by 2025 of advanced solid-state lighting technologies that are much more energy efficient, longer lasting, and cost competitive than conventional lighting technologies. The prime contender to meet this goal is a white-light unit made from a combination of high-performance red, blue, and green LEDs. Researchers have made major strides in advancing the design of red and blue LEDs, but the technology behind green LEDs has lagged behind substantially. Green light is an essential piece of the puzzle because it addresses the peak of the human eye's sensitivity, providing balance to the colors of red and blue light. Researchers originally discovered that green LEDs could be made by simply adding indium (In) to the gallium nitride (GaN) materials that composed blue LEDs, but the materials produced to date have been inefficient, resulting in green LEDs that are too dim to be used for lighting homes and offices. Researchers plan to focus instead on aspects of the "piezoelectric effect" — a property of some materials that causes them to produce an electrical field when pressure is applied. By controlling this effect, they hope to develop a process to make higher-intensity green LEDs that convert electricity into light more efficiently. The research was one of 16 projects selected for funding through DOE's Solid-State Lighting Core Technologies Funding Opportunity Announcement, which seeks to support multiple enabling or fundamental solid-state lighting technology areas for general illumination applications. write your comments about the article :: © 2006 Construction News :: home page |