Tadashi Nezu, Nikkei Electronics
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Japanese firm and university prototyped a light emitting device that generates visible light by discharging electrons from a silicon device measuring 5nm or smaller into xenon gas.
The device was developed by Matsushita Electric Works Ltd and the Graduate School of Engineering at the Tokyo University of Agriculture and Technology.
The luminance efficiency of the light emitting device can be enhanced easily because it does not utilize electric discharge, according to Matsushita and the University. In theory, the device can provide a luminance efficiency of 150lm/W or higher, according to the two parties. The device reportedly eliminates the need of mercury, unlike fluorescent lamps.
In the prototype, high energy electrons are generated by applying a voltage to the "nanosilicon electron source." Silicon discharges electrons when it is processed on the nano-scale and the prototype device uses this property.
The electrons thus generated are discharged into xenon gas to directly excite xenon molecules. This produces "vacuum ultraviolet light" with a wavelength of 200nm or less. The vacuum ultraviolet light collides with phosphor to be converted into visible light.
The latest technology is expected to be applied to high-efficiency, high-luminance lighting equipment, the two parties said. They plan to improve the properties of the device by further clarifying the emission mechanism and optimizing the device structure.
Details of the technology will be presented at the 21st International Vacuum Nanoelectronics Conference, which runs from July 13-17, 2008, in Poland.