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3 reference results for: Gan

Columbia Encyclopedia

Gan or Kan, river, c.550 mi (885 km) long, flowing north through the plain of central Jiangxi prov., SE China, past Nanchang to Poyang lake. Despite many rapids, it is navigable for junks below Ganzhou and for steamers up to Nanchang. The lower Gan valley is fertile; rice and tea are the main crops.

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IEEE Research Is Hi-Tech, Trusted, And Current - Get A Free Trial.
www.IEEE.org/Innovate

LED, Laser, Solar Wafers
GaN, InGaN, ZnO Substrates/Films High Quality, High Purity, Low Cost
www.cermetinc.com

Wikipedia

Gan may refer to:

A Romanization of the Chinese character 甘 (Gān), an abbreviation for Gansu Province in the People's Republic of China
A Romanization of the Chinese character 赣 (Gàn), an abbreviation for:

Gan River
Jiangxi Province in the People's Republic of China, through which the river flows
Gan (linguistics) varieties of Chinese, which are concentrated in and form the typical speech of Jiangxi
gan is the ISO 639-3 language code for Gan

Gan (deity) a deity worshipped in the vicinity of Thistle Mountain, in Guangxi Province, China.
Gan (Stephen King), the creative overforce in The Dark Tower series by Stephen King
GAN (cycling team), a French cycling team
GaN, Gallium(III) nitride, a direct-bandgap semiconductor material of wurtzite crystal structure
.gan, the file extension for documents created by GanttProject
gan, an Elvish board game played in The Obsidian Trilogy by Mercedes Lackey and James Mallory

In places:

Gan, Norway, a village in Fet in Norway
Gan, Pyrénées-Atlantiques, a commune in the Pyrénées-Atlantiques département in France
Gan (Huvadhu Atoll), Republic of Maldives
Gan (Laamu Atoll), Republic of Maldives
Gan (Seenu Atoll), Republic of Maldives
Gan International Airport, Maldive by IATA code
Gananoque, Ontario, Canada, by local nickname

In fictional characters:

Olag Gan, a fictional character in the British television series Blake's 7
Gan Isurugi, a fictional character from the Rival Schools video game series

GAN as an acronym may refer to:

Generic Access Network formerly known as Unlicensed Mobile Access (UMA)
Giant axonal neuropathy and is also the name of the gene that when mutated causes the disorder.
Global Area Network

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Wikipedia

| Section8 = }} Gallium nitride is a very hard material commonly used in bright LEDs since the 1990s.

The compound is a direct-bandgap semiconductor material of wurtzite crystal structure, with a wide (3.4 eV) band gap, used in optoelectronic, high-power and high-frequency devices. It is a binary group III/group V direct bandgap semiconductor. Its sensitivity to ionizing radiation is low (like other group III nitrides), making it a suitable material for solar cell arrays for satellites. Because GaN transistors can operate at much hotter temperatures and work at much higher voltages than GaAs transistors, they make ideal power amplifiers at microwave frequencies.

Physical properties

GaN is a very hard, mechanically stable material with large heat capacity. In its pure form it resists cracking and can be deposited in thin film on sapphire or silicon carbide, despite the mismatch in their lattice constants. GaN can be doped with silicon (Si) or with oxygen to N-type and with magnesium (Mg) to P-type, however the Si and Mg atoms change the way the GaN crystals grow, introducing tensile stresses and making them brittle. Gallium nitride compounds also tend to have a high spatial defect frequency, on the order of a hundred million to ten billion defects per square centimeter.

GaN-based parts are very sensitive to electrostatic discharge.

Developments

The high crystalline quality of GaN can be realized by low temperature deposited buffer layer technology. This high crystalline quality GaN led to the discovery of p-type GaN, p-n junction blue/UV-LEDs and room-temperature stimulated emission (indispensable for laser action). This has led to the commercialization of high-performance blue LEDs and long-lifetime violet-laser diodes (LDs), and to the development of nitride-based devices such as UV detectors and high-speed field-effect transistors.

High-brightness GaN light-emitting diodes (LEDs) completed the range of primary colors, and made applications such as daylight visible full-color LED displays, white LEDs and blue laser devices possible. The first GaN-based high-brightness LEDs were using a thin film of GaN deposited via MOCVD on sapphire. Other substrates used are zinc oxide, with lattice constant mismatch only 2%, and silicon carbide (SiC).

Group III nitride semiconductors are recognized as one of the most promising materials for fabricating optical devices in the visible short-wavelength and UV region. 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. The large band gap means that the performance of GaN transistors is maintained up to higher temperatures than silicon transistors.The first Gallium Nitride metal/oxide semiconductor field-effect transistor (GaN MOSFET) was experimentally demonstrated by Weixiao Huang of Rensselaer Polytechnic Institute in early 2008

Applications

GaN, when doped with a suitable transition metal such as manganese, is a promising spintronics material (magnetic semiconductors).

Nanotubes of GaN are proposed for applications in nanoscale electronics, optoelectronics and biochemical-sensing applications

A GaN-based blue laser diode is used in the Blu-ray disc technologies, and in devices such as the Sony PlayStation 3.

The mixture of GaN with In (InGaN) or Al (AlGaN) with a band gap dependent on ratio of In or Al to GaN allows to build light emitting diodes (LEDs) with colors that can go from red to blue.

Synthesis

GaN crystals can be grown from a molten Na/Ga melt held under 100atm pressure of N₂ at 750^oC. As Ga will not react with N₂ below 1000^oC the powder must be made from something more reactive, and is usually made in one of the following ways:

Ga + NH₃ -> GaN + 3/2H₂
Ga₂O₃ + NH₃ -> GaN + H₂O

Safety and toxicity aspects

The toxicology of GaN has not been fully investigated. The dust is an irritant to skin, eyes and lungs. The environment, health and safety aspects of gallium nitride sources (such as trimethylgallium and ammonia) and industrial hygiene monitoring studies of MOVPE sources have been reported recently in a review.