Gallium phosphide

Cubic

A = 545.05 pm

Gallium (III) phosphide

Bright orange solid

Fixed

4.1 g · cm -3

1348 ° C

Insoluble in water

Attention

Template: Infobox chemical / molecular formula search is not possible

Gallium phosphide is a binary semiconductor compound of gallium and phosphorus. It is used as material for red, orange and green LEDs since the 1960s. Sulfur or tellurium are used for doping, into an n- type semiconductor, zinc, gallium phosphide 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).

Production and representation

Gallium phosphide is obtained by reaction of gallium and phosphorus at 700 ° C or with phosphorus trichloride. GaP single crystals are in a modified Czochralski process ( flüssigkeitsgekapselter Czochralski process ) won because GaP increasingly decomposed above 900 ° C, which is prevented by a coat of molten boron trioxide and a pressure of 10-100 bar.

Properties

Gallium phosphide having a zinc blende structure, a band gap of 2.25 eV and a lattice constant of 0.545 nm, its electron mobility is 110 cm ² / Vs, and its hole mobility is 75 cm ² / Vs. Its refractive index is wavelength dependent. It is 3.37 in the visible region at 800 nm (IR) only 3.2.