Study looks at blue light-emitting diodes

September 5, 2006

Japanese scientists have proposed a solution to the puzzle of why blue light-emitting diodes are so bright.

Despite huge commercial success, until now the reason for the unusual brightness has not been known. The material they are made from -- indium gallium nitride -- can only be fabricated to such a poor quality that it would not be expected to emit much light.

Shigefusa Chichibu and colleagues at the University of Tsukuba used positron annihilation spectroscopy to show the blue light emission originates from structures that consist of only a few atoms, which is what made them so difficult to observe in experiments.

The authors propose their results agree with an older model of structures formed from just three indium atoms in a chain, alternating with nitrogen, that is, In-N-In-N-In. The researchers suggest in the future, such tiny atomic arrangements might be created on purpose to achieve highly efficient light emission in other materials as well.

Shuji Nakamura, one of the authors of the paper, developed blue LEDs from nitride materials in 1993. For that achievement, he is to be presented Friday with Finland's Millennium Technology Prize.

The research appears in the journal Nature Materials.

Copyright 2006 by United Press International

Explore further: Researchers construct atomic model of an immature retrovirus

Related Stories

Droplets levitate on a cushion of blue light

August 11, 2015

Researchers in France have discovered a new way to levitate liquid droplets, which surprisingly also creates a mini light show, with the droplet sparking as it floats above a faint blue glowing gap.

Is your fear of radiation irrational?

July 14, 2015

Bad Gastein in the Austrian Alps. It's 10am on a Wednesday in early March, cold and snowy – but not in the entrance to the main gallery of what was once a gold mine. Togged out in swimming trunks, flip-flops and a bath ...

Recommended for you

Seeing quantum motion

August 28, 2015

Consider the pendulum of a grandfather clock. If you forget to wind it, you will eventually find the pendulum at rest, unmoving. However, this simple observation is only valid at the level of classical physics—the laws ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.