Posted: June 3, 2009

Replacing traditional lighting can have major impact on saving energy

(Nanowerk News) Add the search for economical, long-lasting, brighter lights that use less energy to the list of energy topics occupying the attention of West Virginia University scientists and engineers.
Clean coal technology, biomass energy generation, solar panels and wind turbines may take center stage in the public’s perception of major energy research, but according to WVU Associate Professor Dimitris Korakakis, the quest for alternatives to traditional lighting can also have a major impact on saving energy.
Korakakis, along with Assistant Professor Xian-An Cao, of the WVU Lane Department of Computer Science and Electrical Engineering, have been developing the next generation of light-emitting diode ( LED ) lighting that will be much more efficient than anything now on the commercial market.
The team’s work was the subject of an initial grant based on IC INOVA’s LED design and funding. A recent memorandum of understanding between the WVU Research Corporation and IC INOVA, a Japanese company, demonstrates their support in the progress of the WVU LED research. Officials of IC INOVA recently visited Morgantown to add encouragement to the research efforts.
LED lighting was first invented in Russia in the 1920s and became a practical electronic component in America in the early 1960s. It is based on the discovery that when, in solid state physics, a semiconductor diode is switched on, electrons ( a subatomic particle that carries a negative electric charge ) recombine with “holes” and energy is released in the form of light. The process is called electroluminescence.
The advantages of LED lights are that they use less energy and last longer than conventional sources, like the incandescent or fluorescent bulbs. But, they are expensive because they require advanced materials and device design that traditional light sources do not require. That expense sometimes stands as a barrier to more effective use of LED lighting and an additional conservation of energy on a widespread scale.
At WVU, Korakakis, Cao, and IC INOVA are working on making the lights less expensive and even more efficient thus contributing to the drive to reduce the world’s energy consumption. Among the graduate research assistants that work on the project is Lee Rodak, a West Virginia native who received a National Science Foundation ( NSF ) fellowship in Summer 08 to work on this project in Japan.
Korakakis said their work centers on getting more light output per power used in LED structures. He said that in current LED lighting, only about 50 percent of the power consumed comes out as light whereas for a commercially viable device a target of 70-80 percent is set.
“We are working toward the goal of getting those numbers into the range of 60 to 80 percent,” Korakakis said. “It is research to increase the light extraction efficiency rate.”
Because the WVU research focuses on manipulation of subatomic particles and electron holes as part of the solid state LED process, the researchers are a part of WVNano. The main objective of WVNano is to advance the state’s research environment and diversify the economic base by cultivating a vigorous nanoscale research and engineering program.
Nanoscience is the science of the extremely tiny - not as small as atoms or molecules, but much smaller than anything that can be seen without assistance. WVNano’s research focuses on potential applications in the areas of public security, health, energy and the environment.
WVNano hosted a signing ceremony where representatives of IC INOVA and WVU put signatures to a document pledging further cooperative work on the projects.
John Liddell, director of IC INOVA USA said the company has worked with WVU for about five years and looks forward to commercializing the new LED technology resulting from this research.
“This is an agreement to continue cooperation in further development of research to enhance the capabilities of LED lighting,” Liddell said. “We recognize the successes of previous WVU research and we look forward to continuing our relationship.”
Source: West Virginia University