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A laser diode is a semiconductor device similar to a light-emitting diode in which a diode pumped directly with electrical current can create lasing conditions at the diode's junction.
Gallium arsenide (GaAs) is a III-V direct band gap semiconductor with a zinc blende crystal structure.
Epitaxy refers to a type of crystal growth or material deposition in which new crystalline layers are formed with one or more well-defined orientations with respect to the crystalline seed layer. The deposited crystalline film is called an epitaxial film or epitaxial layer. The relative orientation(s) of the epitaxial layer to the seed layer is defined in terms of the orientation of the crystal lattice of each material. For most epitaxial growths, the new layer is usually crystalline and each crystallographic domain of the overlayer must have a well-defined orientation relative to the substrate crystal structure. Epitaxy can involve single-crystal structures, although grain-to-grain epitaxy has been observed in granular films. For most technological applications, single domain epitaxy, which is the growth of an overlayer crystal with one well-defined orientation with respect to the substrate crystal, is preferred. Epitaxy can also play an important role while growing superlattice structures.
Gallium nitride is a binary III/V direct bandgap semiconductor commonly used in blue light-emitting diodes since the 1990s. The compound is a very hard material that has a Wurtzite crystal structure. Its wide band gap of 3.4 eV affords it special properties for applications in optoelectronic, high-power and high-frequency devices. For example, GaN is the substrate which makes violet (405 nm) laser diodes possible, without requiring nonlinear optical frequency-doubling.
A quantum well is a potential well with only discrete energy values.
A high-electron-mobility transistor, also known as heterostructure FET (HFET) or modulation-doped FET (MODFET), is a field-effect transistor incorporating a junction between two materials with different band gaps as the channel instead of a doped region. A commonly used material combination is GaAs with AlGaAs, though there is wide variation, dependent on the application of the device. Devices incorporating more indium generally show better high-frequency performance, while in recent years, gallium nitride HEMTs have attracted attention due to their high-power performance. Like other FETs, HEMTs are used in integrated circuits as digital on-off switches. FETs can also be used as amplifiers for large amounts of current using a small voltage as a control signal. Both of these uses are made possible by the FET’s unique current–voltage characteristics. HEMT transistors are able to operate at higher frequencies than ordinary transistors, up to millimeter wave frequencies, and are used in high-frequency products such as cell phones, satellite television receivers, voltage converters, and radar equipment. They are widely used in satellite receivers, in low power amplifiers and in the defense industry.
Aluminium nitride (AlN) is a solid nitride of aluminium. It has a high thermal conductivity of up to 321 W/(m·K) and is an electrical insulator. Its wurtzite phase (w-AlN) has a band gap of ~6 eV at room temperature and has a potential application in optoelectronics operating at deep ultraviolet frequencies.
Magnetic semiconductors are semiconductor materials that exhibit both ferromagnetism and useful semiconductor properties. If implemented in devices, these materials could provide a new type of control of conduction. Whereas traditional electronics are based on control of charge carriers, practical magnetic semiconductors would also allow control of quantum spin state. This would theoretically provide near-total spin polarization, which is an important property for spintronics applications, e.g. spin transistors.
The heterojunction bipolar transistor (HBT) is a type of bipolar junction transistor (BJT) which uses differing semiconductor materials for the emitter and base regions, creating a heterojunction. The HBT improves on the BJT in that it can handle signals of very high frequencies, up to several hundred GHz. It is commonly used in modern ultrafast circuits, mostly radio frequency (RF) systems, and in applications requiring a high power efficiency, such as RF power amplifiers in cellular phones. The idea of employing a heterojunction is as old as the conventional BJT, dating back to a patent from 1951. Detailed theory of heterojunction bipolar transistor was developed by Herbert Kroemer in 1957.
Indium nitride is a small bandgap semiconductor material which has potential application in solar cells and high speed electronics.
Indium gallium phosphide (InGaP), also called gallium indium phosphide (GaInP), is a semiconductor composed of indium, gallium and phosphorus. It is used in high-power and high-frequency electronics because of its superior electron velocity with respect to the more common semiconductors silicon and gallium arsenide.
Indium gallium arsenide (InGaAs) is a ternary alloy of indium arsenide (InAs) and gallium arsenide (GaAs). Indium and gallium are group III elements of the periodic table while arsenic is a group V element. Alloys made of these chemical groups are referred to as "III-V" compounds. InGaAs has properties intermediate between those of GaAs and InAs. InGaAs is a room-temperature semiconductor with applications in electronics and photonics.
Indium gallium nitride is a semiconductor material made of a mix of gallium nitride (GaN) and indium nitride (InN). It is a ternary group III/group V direct bandgap semiconductor. Its bandgap can be tuned by varying the amount of indium in the alloy. InxGa1−xN has a direct bandgap span from the infrared for InN to the ultraviolet of GaN. The ratio of In/Ga is usually between 0.02/0.98 and 0.3/0.7.
Aluminium gallium indium phosphide is a semiconductor material that provides a platform for the development of novel multi-junction photovoltaics and optoelectronic devices, as it spans a direct bandgap from deep ultraviolet to infrared.
Indium gallium aluminium nitride is a GaN-based compound semiconductor. It is usually prepared by epitaxial growth, such as metalorganic chemical vapour deposition (MOCVD), molecular-beam epitaxy (MBE), pulsed laser deposition (PLD), etc. This material is used for specialist opto-electronics applications, often in blue laser diodes and LEDs.
A quantum well laser is a laser diode in which the active region of the device is so narrow that quantum confinement occurs. Laser diodes are formed in compound semiconductor materials that are able to emit light efficiently. The wavelength of the light emitted by a quantum well laser is determined by the width of the active region rather than just the bandgap of the materials from which it is constructed. This means that much shorter wavelengths can be obtained from quantum well lasers than from conventional laser diodes using a particular semiconductor material. The efficiency of a quantum well laser is also greater than a conventional laser diode due to the stepwise form of its density of states function.
IQE PLC is a British semiconductor company founded 1988 in Cardiff, Wales, which manufactures advanced epitaxial wafers for a wide range of technology applications for wireless, optoelectronic, electronic and solar devices. IQE specialises in advanced silicon and compound semiconductor materials based on gallium arsenide (GaAs), indium phosphide (InP), gallium nitride (GaN) and silicon. The company is the largest independent outsource producer of epiwafers manufactured by metalorganic vapour phase epitaxy (MOCVD), molecular beam epitaxy (MBE) and chemical vapor deposition (CVD).
Steven P. DenBaars is an American material scientist, electrical engineer, and academic. He is a professor of Materials and Electrical and Computer Engineering, and the executive director of the Solid State Lighting and Energy Electronics Center at the University of California, Santa Barbara. He is also a Fellow of National Academy of Inventors (NAI), and was selected as a Member of National Academy of Engineering (NAE) in 2012 for contributions to gallium nitride-based materials and devices for solid state lighting and displays.
Aristos Christou is an American engineer and scientist, academic professor and researcher. He is a Professor of Materials Science, Professor of Mechanical Engineering and Professor of Reliability Engineering at the University of Maryland.
References
- ↑ Maier, D.; Alomari, M.; Grandjean, N.; Carlin, J.-F.; Diforte-Poisson, M.-A.; et al. (2012). "InAlN/GaN HEMTs for Operation in the 1000°C Regime: A First Experiment". IEEE Electron Device Letters. Institute of Electrical and Electronics Engineers (IEEE). 33 (7): 985–987. doi:10.1109/led.2012.2196972. ISSN 0741-3106. S2CID 328833.
- ↑ Smith, M D; O’Mahony, D; Vitobello, F; Muschitiello, M; Costantino, A; et al. (2015-12-14). "A comparison of the 60Co gamma radiation hardness, breakdown characteristics and the effect of SiNx capping on InAlN and AlGaN HEMTs for space applications". Semiconductor Science and Technology. IOP Publishing. 31 (2): 025008. doi:10.1088/0268-1242/31/2/025008. ISSN 0268-1242.
- ↑ Xue, JunShuai; Hao, Yue; Zhou, XiaoWei; Zhang, JinCheng; Yang, ChuanKai; et al. (2011). "High quality InAlN/GaN heterostructures grown on sapphire by pulsed metal organic chemical vapor deposition". Journal of Crystal Growth. Elsevier BV. 314 (1): 359–364. Bibcode:2011JCrGr.314..359X. doi:10.1016/j.jcrysgro.2010.11.157. ISSN 0022-0248.
- ↑ Higashiwaki, M., et al, (2006), Molecular Beam Epitaxy, 2002 International Conference on, p. 235
- ↑ Smith, Matthew D.; Sadler, Thomas C.; Li, Haoning; Zubialevich, Vitaly Z.; Parbrook, Peter J. (2013-08-19). "The effect of a varied NH3 flux on growth of AlN interlayers for InAlN/GaN heterostructures". Applied Physics Letters. AIP Publishing. 103 (8): 081602. Bibcode:2013ApPhL.103h1602S. doi:10.1063/1.4818645. hdl: 10468/4280 . ISSN 0003-6951.
- ↑ Smith, M. D.; Taylor, E.; Sadler, T. C.; Zubialevich, V. Z.; Lorenz, K.; et al. (2014). "Determination of Ga auto-incorporation in nominal InAlN epilayers grown by MOCVD" (PDF). Journal of Materials Chemistry C. Royal Society of Chemistry (RSC). 2 (29): 5787. doi:10.1039/c4tc00480a. ISSN 2050-7526.
- ↑ Smith, M. D.; O'Mahony, D.; Conroy, M.; Schmidt, M.; Parbrook, P. J. (2015-09-14). "InAlN high electron mobility transistor Ti/Al/Ni/Au Ohmic contact optimisation assisted by in-situ high temperature transmission electron microscopy". Applied Physics Letters. AIP Publishing. 107 (11): 113506. Bibcode:2015ApPhL.107k3506S. doi:10.1063/1.4930880. ISSN 0003-6951.