Nitrides blue

Atomic arrangement of GaN

Nitrides have wurtzite atomic structure as in the left figure, which is different from conventional semiconductor materials such as Si and GaAs, and leads to asymmetric physical properties.


About "Nitride"? You may know the device lighting blue at an antenna of handy phone, which is made of nitride. In this device called the light-emitting diode (LED), injected current is directly converted into light. This light source has no heating parts nor discharging parts, therefore, it has very effective and long lifetime. If all traffic signals in Japan were replaced into LEDs, it is possible to save energy corresponding to 7 atomic power plants. The blue LED, which emits one of three primary colors, had not been achieved until the 2nd half of 80s.

http://www.meijo-u.ac.jp/ST/coe/ENGLISH/NNtoha.html