Green LEDs

Researchers from Rensselaer Polytechnic Institute have developed a new method for the production of green LEDs with increased light output.

A team of researchers led by physics professor, Christian Wetzel (Christian Wetzel) could improve the technique of etching nanoscale layers at the interface between the sapphire base and a layer of gallium nitride, which gives the green glow of LEDs. The new technique significantly improves the light output of green LEDs, which has long eluded.
"Creating a vibrant cheap green LEDs was much more difficult than thought academia and industry, - says Christian Wetzel. - Every computer screen and the TV generates a color image using red, blue and green colors. We already have a powerful, cheap red and blue LEDs. As soon as we can develop a similar green, it will be possible to move to a new generation of high-performance, energy efficient displays.
Sapphire is a widely used and one of the least expensive materials for the production of LEDs. Hence the opening Wetzel may have good prospects for rapidly growing LED industry.
LED lighting requires a small fraction of electricity needed conventional incandescent lamps. In addition, LEDs are very durable and almost not heated. Color LED light emission depends on the type of semiconductor material. The first LEDs were red, and then appeared orange. Years later came blue LEDs, which are now widely used to backlight screens of mobile phones, laptop computers and other electronic devices. Real breakthrough began with a white LED light, which immediately found application in automotive headlamps, flashlights, lighting chambers of refrigerators, etc. In fact, white light in such devices is usually obtained by coating with yellow phosphorus conventional blue LEDs. It adds "extra" step in the production process and leads to "false" white lights with a noticeable bluish tint.
The key to this white LEDs, according to, Christian Wetzel, lies in creating a bright green LED light - enough to combine with the existing high red and blue LEDs, and you can get any color visible to the human eye, including this white.
The research team from Rensselaer Polytechnic Institute as close as to overcome the gap in the brightness of green LEDs and resolve technological barrier to the development of new cost-effective displays.