Aluminium Selenide

Aluminium selenide is the inorganic compound with the formula Al₂Se₃.

It is a solid prepared by igniting a mixture of the elements:

2 Al + 3 Se → Al₂Se₃

The pure compound is white, but typical samples are coloured. Samples of aluminium selenide must be protected from moisture, because the compound hydrolyzes readily, giving off highly toxic hydrogen selenide gas:

Al₂Se₃ + 3 H₂O → Al₂O₃ + 3 H₂Se

Al₂Se₃ has been used as a precursor to hydrogen selenide, which is released when the solid is treated with acids.