Gallium nitride (GaN) is a wide bandgap semiconductor material used in optoelectronic, high-power and high-frequency devices. In solid state physics and related applied fields, the band gap is the energy difference between the top of the valence band and the bottom of the conduction band in insulators and semiconductors. ... A semiconductor is a material with an electrical conductance that is intermediate to those of an insulator and a conductor. ... Optoelectronics is the study and application of electronic devices that interact with light. ...

Until 1993, the only blue light-emitting devices commercially available were based on silicon carbide, which has an indirect bandgap, and so is not capable of sufficient brightness to be of wide interest. Silicon carbide (SiC), also known as carborundum or moissanite, is a ceramic compound of silicon and carbon. ... In semiconductor physics, an indirect bandgap is a bandgap in which the minimum energy in the conduction band is shifted by a k-vector, which is determined by the materials crystal structure. ...

The development of the first high-brightness GaN light-emitting diode (LED) by Shuji Nakamura, working for the Nichia company in Japan, completed the range of primary colors, and made possible applications such as daylight visible full-color LED displays, white LEDs and blue laser devices. GaN-based blue laser diodes are used in the Blu-ray disc technology, used in devices such as the Sony PlayStation 3. Various light-emitting diodes (5 mm reds, 3 mm greens and yellows) A light-emitting diode (LED) is a semiconductor device that emits incoherent monochromatic light when electrically biased in the forward direction. ... Shuji Nakamura (中村修二, born in May 22, 1954, Seto, Ehime, Japan) is a professor at the University of California, Santa Barbara (UCSB). ... Laser (US Air Force) A laser (Light Amplification by Stimulated Emission of Radiation) is a device which uses a quantum mechanical effect, stimulated emission, to generate a coherent beam of light from a lasing medium of controlled purity, size, and shape. ... Blu-ray discs Blu-ray Disc is a next-generation optical disc format meant for high definition video (HD) and high density data storage, and is one of two competing standards for HD optical media. ... Sony Computer Entertainment Inc. ... The PlayStation 3 (colloquially known as the PS3) is the next video game console in Sony Computer Entertainments (SCEI) market-leading PlayStation series. ...

Potential markets for high-power/high-frequency devices based on GaN include microwave radio-frequency power amplifiers (such as used in high-speed wireless data transmission) and high-voltage switching devices for power grids. A potential mass-market application for GaN-based RF transistors is as the microwave source for microwave ovens, replacing the magnetrons currently used. Microwave oven A microwave oven is a kitchen appliance employing microwave radiation primarily to cook or heat food. ... A magnetron is a high-powered vacuum tube that generates coherent microwaves. ...

GaN, when doped with a suitable transition element such as Manganese, is also a promising spintronics material. See Magnetic semiconductor. This article is in need of attention. ... General Name, Symbol, Number manganese, Mn, 25 Chemical series transition metals Group, Period, Block 7 , 4, d Density, Hardness 7470 kg/m3, 6. ... Spintronics (a neologism for spin-based electronics), also known as magnetoelectronics, is an emergent technology which exploits the quantum propensity of electrons to spin as well as making use of their charge state. ... Magnetic semiconductors are materials that exhibit both ferromagnetism (or a similar response) and useful semiconductor properties. ...

Further reading

• Shuji Nakamura, Gerhard Fasol, Stephen J. Pearton, The Blue Laser Diode : The Complete Story, Springer; 2nd edition, October 2, 2000, (ISBN 3540665056)

External link

• UCSB Press release describing Shuji Nakamura's work
• Slide presentation about Shuji Nakamura's work