Gallium phosphide
| Crystal structure | ||||||||||||||||
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| __ Ga 3+ __ P 3− | ||||||||||||||||
| Crystal system |
cubic |
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| Space group |
F 4 3 m (No. 216) |
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| Lattice parameters |
a = 545.05 pm |
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| General | ||||||||||||||||
| Surname | Gallium phosphide | |||||||||||||||
| other names |
Gallium (III) phosphide |
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| Ratio formula | GaP | |||||||||||||||
| Brief description |
light orange solid |
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| External identifiers / databases | ||||||||||||||||
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| properties | ||||||||||||||||
| Molar mass | 100.7 g mol −3 | |||||||||||||||
| Physical state |
firmly |
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| density |
4.1 g cm −3 |
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| Melting point |
1348 ° C |
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| solubility |
almost insoluble in water |
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| Refractive index |
3.3798 |
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| safety instructions | ||||||||||||||||
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C | ||||||||||||||||
Gallium phosphide is a binary semiconductor compound made from gallium and phosphorus . It has been used as a material for red, orange and green light emitting diodes since the 1960s . Sulfur or tellurium are used for doping to transform gallium phosphide into an n-type semiconductor, zinc to transform it into a p-type semiconductor. Pure GaP LEDs emit green light with a wavelength of 555 nm. Nitrogen- doped GaP emits yellow-green (565 nm), zinc oxide- doped GaP red (700 nm).
Extraction and presentation
Gallium phosphide can be obtained by reacting gallium and phosphorus at 700 ° C or with phosphorus trichloride . GaP single crystals are obtained in a modified Czochralski process (liquid-encapsulated Czochralski process), as GaP increasingly decomposes from 900 ° C, which is prevented by a jacket of molten boron trioxide and an overpressure of 10 to 100 bar.
properties
Gallium phosphide has a zincblende structure , a band gap of 2.25 eV and a lattice constant of 0.545 nm. Its electron mobility is 110 cm² / Vs and its hole mobility is 75 cm² / Vs. Its refractive index is dependent on the wavelength . It is 3.37 in the visible range, at 800 nm (IR) only 3.2.
See also
Individual evidence
- ↑ a b c ioffe.ru: Basic Parameters of Gallium Phosphide .
- ↑ a b c d data sheet gallium phosphide from AlfaAesar, accessed on February 6, 2010 ( PDF )(JavaScript required) .
- ↑ refractiveindex.info: Optical constants of GaP (Gallium phosphide) , accessed on November 17, 2014.
- ↑ a b data sheet gallium phosphide from Sigma-Aldrich , accessed on April 2, 2011 ( PDF ).
- ↑ Georg Brauer (Ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 862.