|Jmol-3D images||Image 1|
|Molar mass||100.697 g/mol|
|Appearance||pale orange solid|
|Melting point||1,477 °C (2,691 °F; 1,750 K)|
|Solubility in water||insoluble|
|Band gap||2.26 eV (300 K)|
|Electron mobility||250 cm2/(V*s) (300 K)|
|Thermal conductivity||1.1 W/(cm*K) (300 K)|
|Refractive index (nD)||3.02 (2.48 µm), 3.19 (840 nm), 3.45 (550 nm), 4.30 (262 nm)|
|Crystal structure||Zinc Blende|
|Lattice constant||a = 545.05 pm|
|EU Index||Not listed|
|Flash point||110 °C (230 °F; 383 K)|
|Other anions||Gallium nitride
|Other cations||Aluminium phosphide
|Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)|
|(what is: / ?)|
Gallium phosphide (GaP), a phosphide of gallium, is a compound semiconductor material with an indirect band gap of 2.26 eV(300K). The polycrystalline material has the appearance of pale orange pieces. Undoped single crystal wafers appear clear orange, but strongly doped wafers appear darker due to free-carrier absorption. It is odorless and insoluble in water.
Gallium phosphide is used in the manufacture of low-cost red, orange, and green light-emitting diodes (LEDs) with low to medium brightness since the 1960s. It has a relatively short life at higher current and its lifetime is sensitive to temperature. It is used standalone or together with gallium arsenide phosphide.
Gallium phosphide is transparent for yellow and red light, therefore GaAsP-on-GaP LEDs are more efficient than GaAsP-on-GaAs.
At temperatures above ~900 °C, gallium phosphide dissociates and the phosphorus escapes as a gas. In crystal growth from a 1500 °C melt (for LED wafers), this must be prevented by holding the phosphorus in with a blanket of molten boric oxide in inert gas pressure of 10-100 atmospheres. The process is called Liquid Encapsulated Czochralski (LEC) growth, an elaboration of the Czochralski process used for silicon wafers.