Green LED TVs and computers ‘a step closer to reality’

Scientists have developed a new method for manufacturing green-colored LEDs with greatly enhanced light output, which could likely lead to a new generation of high-performance, energy-efficient display devices.

First discovered in the 1920s, LEDs – light-emitting diodes – are semiconductors that convert electricity into light.

The research team, led by Christian Wetzel, professor of physics at Rensselaer Polytechnic Institute, etched a nanoscale pattern at the interface between the LED’s sapphire base and the layer of gallium nitride (GaN) that gives the LED its green color.

Overall, the new technique resulted in green LEDs with significant enhancements in light extraction, internal efficiency, and light output.

The discovery has brought Wetzel a step closer to his goal of developing a high-performance, low-cost green LED.

“Green LEDs are proving much more challenging to create than academia and industry ever imagined,” Wetzel said.

“Every computer monitor and television produces its picture by using red, blue, and green. We already have powerful, inexpensive red and blue LEDs. Once we develop a similar green LED, it should lead to a new generation of high-performance, energy-efficient display and illumination devices.

“This new research finding is an important step in the right direction,” he said.

Pairing the existing high-performance red LEDs and blue LEDs exist with a comparable green LED should allow devices to produce every color visible to the human eye – including true white, Wetzel added.

The study has been published in the Virtual Journal of Nanoscale Science & Technology.