Aluminium gallium arsenide (also Aluminum gallium arsenide) (Al_xGa_1-xAs) is a semiconductor with very nearly the same lattice constant as GaAs, but a larger bandgap. The x in the formula above is a number between 0 and 1 - this indicates an arbitrary alloy between GaAs and AlAs .

The bandgap varies between 1.42 eV (GaAs) and 2.16 eV (AlAs). For x < 0.4, the bandgap is direct.

The formula AlGaAs should be considered an abbreviated form of the above, rather than any particular ratio.

External link

• Extensive site on the physical properties of aluminium gallium arsenide