Study looks at blue light-emitting diodes

Sep 05, 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: To conduct, or to insulate? That is the question

Related Stories

Helium-shrouded planets may be common in our galaxy

Jun 11, 2015

They wouldn't float like balloons or give you the chance to talk in high, squeaky voices, but planets with helium skies may constitute an exotic planetary class in our Milky Way galaxy. Researchers using ...

Recommended for you

To conduct, or to insulate? That is the question

Jul 02, 2015

A new study has discovered mysterious behaviour of a material that acts like an insulator in certain measurements, but simultaneously acts like a conductor in others. In an insulator, electrons are largely stuck in one place, ...

How oversized atoms could help shrink

Jul 01, 2015

"Lab-on-a-chip" devices – which can carry out several laboratory functions on a single, micro-sized chip – are the result of a quiet scientific revolution over the past few years. For example, they enable ...

User comments : 0

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.