Gallium(III) nitride
From Wikipedia, the free encyclopedia
| Gallium(III) nitride | |
|---|---|
| General | |
| Systematic name | Gallium(III) nitride |
| Other names | None Listed. |
| Molecular formula | GaN |
| Molar mass | 83.7297 g/mol |
| Appearance | Yellow powder. |
| CAS number | [25617-97-4] |
| Properties | |
| Density and phase | 6.1 g/cm3, solid |
| Solubility in water | Reacts. |
| Melting point | >2500°C |
| Boiling point | - |
| Basicity (pKb) | N/A |
| Hazards | |
| MSDS | External MSDS |
| EU classification | None listed. |
| R-phrases | R36, R37, R38, R43. |
| S-phrases | S24, S37. |
| NFPA 704 | N/A |
| Flash point | Non-flammable. |
| Supplementary data page | |
| Structure and properties |
n, εr, etc. |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Related compounds | |
| Other anions | None listed. |
| Other cations | None listed. |
| Related bases | None listed. |
| Related compounds | BN, InN, AlN |
| GaP | |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
|
Gallium nitride (GaN) 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.
Contents |
[edit] Applications
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.
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.
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).
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.
GaN, when doped with a suitable transition metal such as Manganese, is also a promising spintronics material. See Magnetic semiconductor.
GaN nanotubes have also been produced, with proposed applications in nanoscale electronics, optoelectronics and biochemical-sensing applications
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, despite the mismatch in their lattice constants. GaN can be doped with silicon to N-type, however the silicon atoms change the way of the growth of the GaN crystals, introducing tensile stresses and making them brittle. GaN crystals are also rich in defects; 100 million to 10 billion per cm². [3]
Mixing GaN with InN yields InGaN, a semiconductor material with band gap dependent on ratio of InN to GaN and a high tolerance to lattice defects.
GaN and InGaN based parts are very sensitive to electrostatic discharge.
[edit] Precautions
The toxicology of GaN has not been fully investigated. The dust is an irritant to skin, eyes and lungs.
[edit] Further reading
- Shuji Nakamura, Gerhard Fasol, Stephen J. Pearton, The Blue Laser Diode : The Complete Story, Springer; 2nd edition, October 2, 2000, (ISBN 3-540-66505-6)
- Jacques I. Pankove, T. D. Moustakas, Gallium Nitride (GaN) II: Semiconductors and Semimetals, Academic Press, 1998 (ISBN 0-12-752166-6)
[edit] References
- ↑ - Shuji Nakamura, Gerhard Fasol, Stephen J Pearton The Blue Laser Diode: The Complete Story, Springer Verlag, 2nd Edition (October 2, 2000)
- ↑ - Harafuji, Tsuchiya and Kawamura, J. Appl. Phys. 96, 2501-2512 (September 1, 2004)
- ↑ - Goldberger et al, Nature 422, 599-602 (10 April 2003)
[edit] External links
[edit] Generic
- The Cambridge center for galium nitride (GaN).
- External MSDS Data Sheet.
- Ioffe data archive
- National Compound Semiconductor Roadmap page at ONR
- Nitronex Nitronex is a corporation that is experimenting with GaN on silicon to make RF power transistors.
