05-13-2023-1631 - Proto-Uralic, 7000–2000 BCE, Western Siberia or West Siberia , etc. (draft)

Proto-Uralic is the unattested reconstructed language ancestral to the modern Uralic language family. The hypothetical language is thought to have been originally spoken in a small area in about 7000–2000 BCE, and expanded to give differentiated Proto-Languages. Some newer research has pushed the "Proto-Uralic homeland" east of the Ural Mountains into Western Siberia.^[2] 

https://en.wikipedia.org/wiki/Proto-Uralic_language

Western Siberia or West Siberia (Russian: Западная Сибирь, romanized: Zapadnaya Sibir'; Kazakh: Батыс Сібір) is a part of the larger region of Siberia that is mostly located in the Russian Federation. It lies between the Ural region and the Yenisei River, which conventionally divides Siberia into two halves.

Western Siberia covers an area of 2,500,000 square kilometers (970,000 sq mi), nearly 80% of which is located within the West Siberian Plain. The largest rivers of the region are the Irtysh and the Ob.^[1]

The West Siberian petroleum basin is the largest hydrocarbon (petroleum and natural gas) basin in the world covering an area of about 2.2 million km², and is also the largest oil and gas producing region in Russia.^[2]

In medieval times, the region was part of the Golden Horde. After its gradual decline during the 15th century, the Khanate of Sibir, centered on Tyumen, was formed within the area. In the late 16th century, most of Western Siberia was conquered by the Russian Empire, while its southern region became part of the Kazakh Khanate. The current international borders between Russia and Kazakhstan came into being in the late 20th century following the dissolution of the Soviet Union. 

https://en.wikipedia.org/wiki/Western_Siberia

 

 

05-13-2023-1630 - Gothenburg

 

Gothenburg (/ˈɡɒθənbɜːrɡ/ (listen);^[5] abbreviated Gbg;^[6][7] Swedish: Göteborg [jœtɛˈbɔrj] (listen)) is the second-largest city in Sweden, fifth-largest in the Nordic countries, and capital of the Västra Götaland County. It is situated by the Kattegat, on the west coast of Sweden, and has a population of approximately 590,000 in the city proper and about 1.1 million inhabitants in the metropolitan area.^[8]

Gothenburg was founded as a heavily fortified, primarily Dutch, trading colony, by royal charter in 1621 by King Gustavus Adolphus. In addition to the generous privileges (e.g. tax relaxation) given to his Dutch allies from the ongoing Thirty Years' War, the king also attracted significant numbers of his German and Scottish allies to populate his only town on the western coast. At a key strategic location at the mouth of the Göta älv, where Scandinavia's largest drainage basin enters the sea, the Port of Gothenburg is now the largest port in the Nordic countries.^[9]

Gothenburg is home to many students, as the city includes the University of Gothenburg and Chalmers University of Technology. Volvo was founded in Gothenburg in 1927.^[10] The original parent Volvo Group and the now-separate Volvo Car Corporation are still headquartered on the island of Hisingen in the city. Other key companies are Ericsson, SKF and AstraZeneca.

Gothenburg is served by Göteborg Landvetter Airport 25 km (16 mi) southeast of the city center. The smaller Göteborg City Airport, 15 km (9.3 mi) from the city center, was closed to regular airline traffic in 2015.

The city hosts the Gothia Cup, the world's largest youth football tournament, and the Göteborg Basketball Festival, Europe's largest youth basketball tournament, alongside some of the largest annual events in Scandinavia. The Gothenburg Film Festival, held in January since 1979, is the leading Scandinavian film festival, with over 155,000 visitors each year.^[11] In summer, a wide variety of music festivals are held in the city, including the popular Way Out West Festival.

During 2020, Gothenburg's population increased by 3,775 inhabitants.^[12]

Name

Further information: Name of the Goths

The city was named Göteborg in the city's charter in 1621^[13] and simultaneously given the German and English name Gothenburg.^[14] The Swedish name was given after the Göta älv, called Göta River in English,^[15] and other cities ending in -borg.^[16][17][18]

Both the Swedish and German/English names were in use before 1621 and had already been used for the previous city founded in 1604 that burned down in 1611.^[19] Gothenburg is one of few Swedish cities to still have an official and widely used exonym.

The city council of 1641 consisted of four Swedish, three Dutch, three German, and two Scottish members. In Dutch, Scots, English, and German, all languages with a long history in this trade and maritime-oriented city, the name Gothenburg is or was (in the case of German) used for the city. Variations of the official German/English name Gothenburg in the city's 1621 charter existed or exist in many languages. The French form of the city name is Gothembourg, but in French texts, the Swedish name Göteborg is more frequent. In addition, the traditional forms ("Gothenburg" in English, or Gotemburgo in Spanish and Portuguese) are sometimes replaced with the use of the Swedish Göteborg, for example by The Göteborg Opera and the Göteborg Ballet. However, Göteborgs universitet, previously designated as the Göteborg University in English, changed its name to the University of Gothenburg in 2008.^[20] The Gothenburg municipality has also reverted to the use of the English name in international contexts.^[21]

In 2009, the city council launched a new logotype for Gothenburg. Since the name "Göteborg" contains the Swedish letter "ö", they planned to make the name more "international" and "up to date" by turning the "ö" sideways. As of 2015, the name is spelled "Go:teborg" on a large number of signs in the city.^[22] 

https://en.wikipedia.org/wiki/Gothenburg

05-13-2023-1629 - Aluminium gallium indium phosphide (AlGaInP, also AlInGaP, InGaAlP, GaInP, etc.)

Aluminium gallium indium phosphide

Identifiers
CAS Number	163207-18-9
Properties
Chemical formula	AlGaInP
Structure
Crystal structure	Cubic
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Aluminium gallium indium phosphide (AlGaInP, also AlInGaP, InGaAlP, GaInP, etc.) 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.^[1]

AlGaInP is used in manufacture of light-emitting diodes of high-brightness red, orange, green, and yellow color, to form the heterostructure emitting light. It is also used to make diode lasers.

Formation

AlGaInP layer is often grown by heteroepitaxy on gallium arsenide or gallium phosphide in order to form a quantum well structure. Heteroepitaxy is a kind of epitaxy performed with materials that are different from each other. In heteroepitaxy, a crystalline film grows on a crystalline substrate or film of a different material.^{[citation needed]}

This technology is often used to grow crystalline films of materials for which single crystals cannot 1D view.^{[citation needed]}

Another example of heteroepitaxy is gallium nitride (GaN) on sapphire.^[2]

Properties

AlGaInP is a semiconductor, which means that its valence band is completely full. The eV of the band gap between the valence band and the conduction band is small enough that it is able to emit visible light (1.7 eV - 3.1 eV). The band gap of AlGaInP is between 1.81 eV and 2 eV. This corresponds to red, orange, or yellow light, and that is why the LEDs made from AlGaInP are those colors.^[1]

Optical properties
Refractive index	3.49
Chromatic dispersion	-1.68 μm−1
Absorption coefficient	50536 cm−1

Zinc blende structure

A zincblende unit cell

AlGaInP's structure is categorized within a specific unit cell called the zinc blende structure.^[3] Zinc blende/sphalerite is based on a face-centered cubic lattice of anions. It has 4 asymmetric units in its unit cell. It is best thought of as a face-centered cubic array of anions and cations occupying one half of the tetrahedral holes. Each ion is 4-coordinate and has local tetrahedral geometry. Zinc blende is its own antitype—you can switch the anion and cation positions in the cell and it has no effect (as in NaCl). In fact, replacement of both the zinc and sulfur with carbon gives the diamond structure.^[4]

Applications

AlGaInP can be applied to:

• Light emitting diodes of high brightness
• Diode lasers
• Quantum well structures
• Solar cells (potential). The use of aluminium gallium indium phosphide with high aluminium content, in a five junction structure, can lead to solar cells with maximum theoretical efficiencies (solar cell efficiency) above 40%^[1]

AlGaInP laser

A diode laser consists of a semiconductor material in which a p-n junction forms the active medium and optical feedback is typically provided by reflections at the device facets. AlGaInP diode lasers emit visible and near-infrared light with wavelengths of 0.63-0.76 μm.^[5] The primary applications of AlGaInP diode lasers are in optical disc readers, laser pointers, and gas sensors, as well as for optical pumping, and machining.^[1]

LED

AlGaInP can be used as an LED. An LED is composed of a p-n junction which contain a p-type and an n-type. The material used in the semiconducting element of an LED determines its color.^[6]

AlGaInP is one of type of LEDs used for lighting systems. Another is indium gallium nitride (InGaN). Slight changes in the composition of these alloys changes the color of the emitted light. AlGaInP alloys are used to make red, orange and yellow LEDs. InGaN alloys are used to make green, blue and white LEDs.^{[citation needed]}

Safety and toxicity aspects

The toxicology of AlGaInP has not been fully investigated. The dust is an irritant to skin, eyes and lungs. The environment, health and safety aspects of aluminium indium gallium phosphide sources (such as trimethylgallium, trimethylindium and phosphine) and industrial hygiene monitoring studies of standard MOVPE sources have been reported in a review.^[7] Illumination by an AlGaInP laser was associated in one study with slower healing of skin wounds in laboratory rats.^{[8][medical citation needed]}

See also

• Indium phosphide
• Indium gallium phosphide
• Aluminium gallium phosphide
• Indium gallium arsenide phosphide

References

1. 
   

Rodrigo, SM; Cunha, A; Pozza, DH; Blaya, DS; Moraes, JF; Weber, JB; de Oliveira, MG (2009). "Analysis of the systemic effect of red and infrared laser therapy on wound repair". Photomed Laser Surg. 27 (6): 929–35. doi:10.1089/pho.2008.2306. hdl:10216/25679. PMID 19708798.

"Kinetics of Epitaxial Growth: Surface Diffusion and Nucleation. (n.d): 1-10 . Web.

"Krames, Michael, R., Oleg B. Shcekin, Regina Mueller-Mach, Gerd O. Mueller, Ling Zhou, Gerard Harbers, and George M Craford. "Status and Future of High-Power Light-Emitting." JOURNAL OF DISPLAY TECHNOLOGY Vol. 3.No. 2 (2007): 160. Department of Electrical Engineering. 20 July 2009. Web" (PDF). Archived from the original (PDF) on 2015-12-08. Retrieved 2015-12-03.

Toreki, Rob. "The Zinc Blende (ZnS) Structure." Structure World. N.p., 30 Mar. 2015. Web.

Chan, B. L.; Jutamulia, S. (2 December 2010). "Lasers in light skin interaction", Proc. SPIE 7851, Information Optics and Optical Data Storage, 78510O; doi: 10.1117/12.872732

"About LEDs." Rensselaer Magazine: Winter 2004: Looking Into Light. N.p., Dec. 2004. Web.

Shenai-Khatkhate, Deodatta V. (2004). "Environment, health and safety issues for sources used in MOVPE growth of compound semiconductors". Journal of Crystal Growth. 272 (1–4): 816–821. doi:10.1016/j.jcrysgro.2004.09.007.

8. Rodrigo, SM; Cunha, A; Pozza, DH; Blaya, DS; Moraes, JF; Weber, JB; de Oliveira, MG (2009). "Analysis of the systemic effect of red and infrared laser therapy on wound repair". Photomed Laser Surg. 27 (6): 929–35. doi:10.1089/pho.2008.2306. hdl:10216/25679. PMID 19708798.

Notes

• Griffin, I J (2000). "Band structure parameters of quaternary phosphide semiconductor alloys investigated by magneto-optical spectroscopy". Semiconductor Science and Technology. 15 (11): 1030–1034. doi:10.1088/0268-1242/15/11/303.
• High Brightness Light Emitting Diodes:G. B. Stringfellow and M. George Craford, Semiconductors and Semimetals, vol. 48, pp. 97–226.

v t e Aluminium compounds

v t e Gallium compounds

v t e Indium compounds

v t e Phosphorus compounds

v t e Phosphides

Categories:

• III-V semiconductors
• Aluminium compounds
• Gallium compounds
• Indium compounds
• Phosphides
• III-V compounds
• Light-emitting diode materials
• Zincblende crystal structure

• 
  

 

 https://en.wikipedia.org/wiki/Aluminium_gallium_indium_phosphide

 

05-13-2023-1613 - At the edge of a diode laser, where light is emitted, a mirror is traditionally formed by cleaving the semiconductor wafer to form a specularly reflecting plane. ; Aluminium_gallium_indium_phosphide ; Quantum well structures ; heteroepitaxy is gallium nitride (GaN) on sapphire.[2] ; gallium arsenide ; phosphide ; This technology is often used to grow crystalline films of materials for which single crystals cannot 1D view.[citation needed] ; multi-junction photovoltaics and optoelectronic devices ; spans a direct bandgap from deep ultraviolet to infrared ; electromigration ; current crowding ; electron mobility ; electrical contact ; contact explosives ; anti-reflective coating ; chalcogenide glass ; pos fed ; getter ; laser pump ; oxygen ; analogues ; psuedoes ; synthetics ; artificials ; limit ; exceptions ; exemptions ; specular reflection ; surface states ; phonon ; thermal runaway ; laser pumping ; cleavage ; diamond ; four ; Catastrophic_optical_damage ; waveguide ; carrier ; mirror region ; injection ; stream ; string ; thread ; fluid thread breakup ; filament ; twine ; disintegration ; radioactivity ; excission ; foam ; deposition ; thin film ; vortex sheet ; vortex core pin ; microchip ; nano chip ; nano tube ; energy channel ; energy ; optical cavity ; hollow center ; virtual particle ; diamond drill bit ; oscillation ; space ; spectrum ; beam ; quality ; area ; waveguide ; several carrier diffusion distances ; aluminum ; doping ; stimulants ; absorption ; band gap ; lasing wavelength ; semiconductor ; conductor ; GaAs-based lasers, high power diode, ibm, cod, gaas, emission, micrometer, inp, telecom, aluminum oxide, rca, facet, thickness, reduction, impedance, inhibition, heating, broadening, optical cavity, energy density on surface can be reduced by employing a waveguide broadening the optical cavity, wide laser stripe, mag stripe, higher output power, transverse mode oscillasions, worsening, recombination velocity, rate, nuclear rate, ratio, scale, scaling, dimensions, container, control, shift, shifting absorption spectrum, increasing band gap, decreasing absorption of lasing wavelength, passivation layer, layers, vacuum, vaccume, vacume, vacum, surface state, static state, Another approach is doping of the surface, increasing the band gap and decreasing absorption of the lasing wavelength, shifting the absorption maximum several nanometers up.[2] , STP, standing value, Reduction of recombination velocity of surface states can be also achieved by cleaving the crystals in ultrahigh vacuum and immediate deposition of a suitable passivation layer.[2], The absorbed light causes generation of electron-hole pairs. These can lead to breaking of chemical bonds on the crystal surface followed by oxidation, or to release of heat by nonradiative recombination. The oxidized surface then shows increased absorption of the laser light, which further accelerates its degradation. The oxidation is especially problematic for semiconductor layers containing aluminium.[2], cleavage plane, transits to free space from within the semiconductor crystal, Essentially, as a result when light propagates through the cleavage plane and transits to free space from within the semiconductor crystal, a fraction of the light energy is absorbed by the surface states where it is converted to heat by phonon-electron interactions. This heats the cleaved mirror. In addition the mirror may heat simply because the edge of the diode laser—which is electrically pumped—is in less-than-perfect contact with the mount that provides a path for heat removal. The heating of the mirror causes the band gap of the semiconductor to shrink in the warmer areas. The band gap shrinkage brings more electronic band-to-band transitions into alignment with the photon energy causing yet more absorption. This is thermal runaway, a form of positive feedback, and the result can be melting of the facet, known as catastrophic optical damage, or COD. , release of heat by nonradiative recombination. , Surface states at the cleaved plane have energy levels within the (otherwise forbidden) band gap of the semiconductor. , atomic states, properties within the crystal, termination of the perfectly periodic lattice at that plane, surface states, crystallographic plane, vortex plane, bending force, propagate in a straight line across the wafer, crystallographic plane in III-V semiconductor crystals (such as GaAs, InP, GaSb, etc.) compared to other planes. A scratch made at the edge of the wafer and a slight bending force causes a nearly atomically perfect mirror-like cleavage plane to form and propagate in a straight line across the wafer. , At the edge of a diode laser, where light is emitted, a mirror is traditionally formed by cleaving the semiconductor wafer to form a specularly reflecting plane., etc. (draft)

 

Causes and mechanisms

At the edge of a diode laser, where light is emitted, a mirror is traditionally formed by cleaving the semiconductor wafer to form a specularly reflecting plane. This approach is facilitated by the weakness of the [110] crystallographic plane in III-V semiconductor crystals (such as GaAs, InP, GaSb, etc.) compared to other planes. A scratch made at the edge of the wafer and a slight bending force causes a nearly atomically perfect mirror-like cleavage plane to form and propagate in a straight line across the wafer.

But it so happens that the atomic states at the cleavage plane are altered (compared to their bulk properties within the crystal) by the termination of the perfectly periodic lattice at that plane. Surface states at the cleaved plane have energy levels within the (otherwise forbidden) band gap of the semiconductor.

The absorbed light causes generation of electron-hole pairs. These can lead to breaking of chemical bonds on the crystal surface followed by oxidation, or to release of heat by nonradiative recombination. The oxidized surface then shows increased absorption of the laser light, which further accelerates its degradation. The oxidation is especially problematic for semiconductor layers containing aluminium.^[2]

Essentially, as a result when light propagates through the cleavage plane and transits to free space from within the semiconductor crystal, a fraction of the light energy is absorbed by the surface states where it is converted to heat by phonon-electron interactions. This heats the cleaved mirror. In addition the mirror may heat simply because the edge of the diode laser—which is electrically pumped—is in less-than-perfect contact with the mount that provides a path for heat removal. The heating of the mirror causes the band gap of the semiconductor to shrink in the warmer areas. The band gap shrinkage brings more electronic band-to-band transitions into alignment with the photon energy causing yet more absorption. This is thermal runaway, a form of positive feedback, and the result can be melting of the facet, known as catastrophic optical damage, or COD.

Deterioration of the laser facets with aging and effects of the environment (erosion by water, oxygen, etc.) increases light absorption by the surface, and decreases the COD threshold. A sudden catastrophic failure of the laser due to COD then can occur after many thousands hours in service.^[3]

Improvements

One of the methods of increasing the COD threshold in AlGaInP laser structures is the sulfur treatment, which replaces the oxides at the laser facet with chalcogenide glasses.^[4] This decreases the recombination velocity of the surface states.^[2]

Reduction of recombination velocity of surface states can be also achieved by cleaving the crystals in ultrahigh vacuum and immediate deposition of a suitable passivation layer.^[2]

A thin layer of aluminium can be deposited over the surface, for gettering the oxygen.^[2]

Another approach is doping of the surface, increasing the band gap and decreasing absorption of the lasing wavelength, shifting the absorption maximum several nanometers up.^[2]

Current crowding near the mirror area can be avoided by prevention of injecting charge carriers near the mirror region. This is achieved by depositing the electrodes away from the mirror, at least several carrier diffusion distances.^[2]

Energy density on the surface can be reduced by employing a waveguide broadening the optical cavity, so the same amount of energy exits through a larger area. Energy density of 15–20 MW/cm² corresponding to 100 mW per micrometer of stripe width are now achievable. A wider laser stripe can be used for higher output power, for the cost of transverse mode oscillations and therefore worsening of spectral and spatial beam quality.^[2]

In the 1970s, this problem, which is particularly nettlesome for GaAs-based lasers emitting between 1 µm and 0.630 µm wavelengths (less so for InP based lasers used for long-haul telecommunications which emit between 1.3 µm and 2 µm), was identified. Michael Ettenberg, a researcher and later Vice President at RCA Laboratories' David Sarnoff Research Center in Princeton, New Jersey, devised a solution. A thin layer of aluminum oxide was deposited on the facet. If the aluminum oxide thickness is chosen correctly, it functions as an anti-reflective coating, reducing reflection at the surface. This alleviated the heating and COD at the facet.

Since then, various other refinements have been employed. One approach is to create a so-called non-absorbing mirror (NAM) such that the final 10 µm or so before the light emits from the cleaved facet are rendered non-absorbing at the wavelength of interest. Such lasers are called window lasers.

In the very early 1990s, SDL, Inc. began supplying high power diode lasers with good reliability characteristics. CEO Donald Scifres and CTO David Welch presented new reliability performance data at, e.g., SPIE Photonics West conferences of the era. The methods used by SDL to defeat COD were considered to be highly proprietary and have still not been disclosed publicly as of June, 2006.

In the mid-1990s IBM Research (Ruschlikon, Switzerland) announced that it had devised its so-called "E2 process" which conferred extraordinary resistance to COD in GaAs-based lasers. This process, too, has never been disclosed as of June, 2006.

Further reading

Graduate thesis about COD in high power diode lasers from 2013

References

[1] Archived February 13, 2006, at the Wayback Machine

Roland Diehl (2000). High-power diode lasers: fundamentals, technology, applications. Springer. p. 195. ISBN 3-540-66693-1.

Dan Botez, Don R. Scifres (1994). Diode laser arrays. Cambridge University Press. p. 314. ISBN 0-521-41975-1.

4. Kamiyama, Satoshi; Mori, Yoshihiro; Takahashi, Yasuhito; Ohnaka, Kiyoshi (1991). "Improvement of catastrophic optical damage level of AlGaInP visible laser diodes". Applied Physics Letters. 58 (23): 2595. Bibcode:1991ApPhL..58.2595K. doi:10.1063/1.104833.

Categories:

• Semiconductor device defects
• Laser science

 

https://en.wikipedia.org/wiki/Catastrophic_optical_damage

A thin layer of aluminium can be deposited over the surface, for gettering the oxygen.^[2]

Another approach is doping of the surface, increasing the band gap and decreasing absorption of the lasing wavelength, shifting the absorption maximum several nanometers up.^[2]

Current crowding near the mirror area can be avoided by prevention of injecting charge carriers near the mirror region. This is achieved by depositing the electrodes away from the mirror, at least several carrier diffusion distances.^[2]

Energy density on the surface can be reduced by employing a waveguide broadening the optical cavity, so the same amount of energy exits through a larger area. Energy density of 15–20 MW/cm² corresponding to 100 mW per micrometer of stripe width are now achievable. A wider laser stripe can be used for higher output power, for the cost of transverse mode oscillations and therefore worsening of spectral and spatial beam quality.^[2] 

https://en.wikipedia.org/wiki/Catastrophic_optical_damage

https://en.wikipedia.org/wiki/Cleavage_(crystal)

https://en.wikipedia.org/wiki/Miller_index#Crystallographic_planes_and_directions

https://en.wikipedia.org/wiki/Specular_reflection

https://en.wikipedia.org/wiki/Surface_states

https://en.wikipedia.org/wiki/Phonon

https://en.wikipedia.org/wiki/Laser_pumping

https://en.wikipedia.org/wiki/Thermal_runaway

https://en.wikipedia.org/wiki/Positive_feedback

https://en.wikipedia.org/wiki/Chalcogenide_glass

https://en.wikipedia.org/wiki/Getter

https://en.wikipedia.org/wiki/Anti-reflective_coating

https://en.wikipedia.org/wiki/Current_crowding

https://en.wikipedia.org/wiki/P%E2%80%93n_junction

https://en.wikipedia.org/wiki/Electrical_contact

https://en.wikipedia.org/wiki/Electron_mobility

https://en.wikipedia.org/wiki/Current_crowding

https://en.wikipedia.org/wiki/Electromigration

https://en.wikipedia.org/wiki/Aluminium_gallium_indium_phosphide

https://en.wikipedia.org/wiki/Bipolar_junction_transistor

 

 

Aluminium gallium indium phosphide (AlGaInP, also AlInGaP, InGaAlP, GaInP, etc.) 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.^[1]

AlGaInP is used in manufacture of light-emitting diodes of high-brightness red, orange, green, and yellow color, to form the heterostructure emitting light. It is also used to make diode lasers.

Formation

AlGaInP layer is often grown by heteroepitaxy on gallium arsenide or gallium phosphide in order to form a quantum well structure. Heteroepitaxy is a kind of epitaxy performed with materials that are different from each other. In heteroepitaxy, a crystalline film grows on a crystalline substrate or film of a different material.^{[citation needed]}

This technology is often used to grow crystalline films of materials for which single crystals cannot 1D view.^{[citation needed]}

Another example of heteroepitaxy is gallium nitride (GaN) on sapphire.^[2]

Properties

AlGaInP is a semiconductor, which means that its valence band is completely full. The eV of the band gap between the valence band and the conduction band is small enough that it is able to emit visible light (1.7 eV - 3.1 eV). The band gap of AlGaInP is between 1.81 eV and 2 eV. This corresponds to red, orange, or yellow light, and that is why the LEDs made from AlGaInP are those colors.^[1]

Optical properties
Refractive index	3.49
Chromatic dispersion	-1.68 μm−1
Absorption coefficient	50536 cm−1

Zinc blende structure

A zincblende unit cell

AlGaInP's structure is categorized within a specific unit cell called the zinc blende structure.^[3] Zinc blende/sphalerite is based on a face-centered cubic lattice of anions. It has 4 asymmetric units in its unit cell. It is best thought of as a face-centered cubic array of anions and cations occupying one half of the tetrahedral holes. Each ion is 4-coordinate and has local tetrahedral geometry. Zinc blende is its own antitype—you can switch the anion and cation positions in the cell and it has no effect (as in NaCl). In fact, replacement of both the zinc and sulfur with carbon gives the diamond structure.^[4]

Applications

AlGaInP can be applied to:

• Light emitting diodes of high brightness
• Diode lasers
• Quantum well structures
• Solar cells (potential). The use of aluminium gallium indium phosphide with high aluminium content, in a five junction structure, can lead to solar cells with maximum theoretical efficiencies (solar cell efficiency) above 40%^[1]

AlGaInP laser

A diode laser consists of a semiconductor material in which a p-n junction forms the active medium and optical feedback is typically provided by reflections at the device facets. AlGaInP diode lasers emit visible and near-infrared light with wavelengths of 0.63-0.76 μm.^[5] The primary applications of AlGaInP diode lasers are in optical disc readers, laser pointers, and gas sensors, as well as for optical pumping, and machining.^[1]

LED

AlGaInP can be used as an LED. An LED is composed of a p-n junction which contain a p-type and an n-type. The material used in the semiconducting element of an LED determines its color.^[6]

AlGaInP is one of type of LEDs used for lighting systems. Another is indium gallium nitride (InGaN). Slight changes in the composition of these alloys changes the color of the emitted light. AlGaInP alloys are used to make red, orange and yellow LEDs. InGaN alloys are used to make green, blue and white LEDs.^{[citation needed]}

Safety and toxicity aspects

The toxicology of AlGaInP has not been fully investigated. The dust is an irritant to skin, eyes and lungs. The environment, health and safety aspects of aluminium indium gallium phosphide sources (such as trimethylgallium, trimethylindium and phosphine) and industrial hygiene monitoring studies of standard MOVPE sources have been reported in a review.^[7] Illumination by an AlGaInP laser was associated in one study with slower healing of skin wounds in laboratory rats.^{[8][medical citation needed]}

See also

• Indium phosphide
• Indium gallium phosphide
• Aluminium gallium phosphide
• Indium gallium arsenide phosphide

References

1. 
   

Rodrigo, SM; Cunha, A; Pozza, DH; Blaya, DS; Moraes, JF; Weber, JB; de Oliveira, MG (2009). "Analysis of the systemic effect of red and infrared laser therapy on wound repair". Photomed Laser Surg. 27 (6): 929–35. doi:10.1089/pho.2008.2306. hdl:10216/25679. PMID 19708798.

"Kinetics of Epitaxial Growth: Surface Diffusion and Nucleation. (n.d): 1-10 . Web.

"Krames, Michael, R., Oleg B. Shcekin, Regina Mueller-Mach, Gerd O. Mueller, Ling Zhou, Gerard Harbers, and George M Craford. "Status and Future of High-Power Light-Emitting." JOURNAL OF DISPLAY TECHNOLOGY Vol. 3.No. 2 (2007): 160. Department of Electrical Engineering. 20 July 2009. Web" (PDF). Archived from the original (PDF) on 2015-12-08. Retrieved 2015-12-03.

Toreki, Rob. "The Zinc Blende (ZnS) Structure." Structure World. N.p., 30 Mar. 2015. Web.

Chan, B. L.; Jutamulia, S. (2 December 2010). "Lasers in light skin interaction", Proc. SPIE 7851, Information Optics and Optical Data Storage, 78510O; doi: 10.1117/12.872732

"About LEDs." Rensselaer Magazine: Winter 2004: Looking Into Light. N.p., Dec. 2004. Web.

Shenai-Khatkhate, Deodatta V. (2004). "Environment, health and safety issues for sources used in MOVPE growth of compound semiconductors". Journal of Crystal Growth. 272 (1–4): 816–821. doi:10.1016/j.jcrysgro.2004.09.007.

8. Rodrigo, SM; Cunha, A; Pozza, DH; Blaya, DS; Moraes, JF; Weber, JB; de Oliveira, MG (2009). "Analysis of the systemic effect of red and infrared laser therapy on wound repair". Photomed Laser Surg. 27 (6): 929–35. doi:10.1089/pho.2008.2306. hdl:10216/25679. PMID 19708798.

Notes

• Griffin, I J (2000). "Band structure parameters of quaternary phosphide semiconductor alloys investigated by magneto-optical spectroscopy". Semiconductor Science and Technology. 15 (11): 1030–1034. doi:10.1088/0268-1242/15/11/303.
• High Brightness Light Emitting Diodes:G. B. Stringfellow and M. George Craford, Semiconductors and Semimetals, vol. 48, pp. 97–226.

v t e Aluminium compounds

v t e Gallium compounds

v t e Indium compounds

v t e Phosphorus compounds

v t e Phosphides

Categories:

• III-V semiconductors
• Aluminium compounds
• Gallium compounds
• Indium compounds
• Phosphides
• III-V compounds
• Light-emitting diode materials
• Zincblende crystal structure

https://en.wikipedia.org/wiki/Aluminium_gallium_indium_phosphide