Zinc arsenide (Zn<sub>3</sub>As<sub>2</sub>) is a binary compound of zinc with arsenic which forms gray tetragonal crystals. It is an inorganic semiconductor with a band gap of 1.0 eV.
Zinc arsenide can be prepared by the reaction of zinc with arsenic
Zn<sub>3</sub>As<sub>2</sub> has a room-temperature tetragonal form that converts to a different tetragonal phase at 190 ðC and to a third phase at 651 ðC. In the room-temperature form, the zinc atoms are tetrahedrally coordinated and the arsenic atoms are surrounded by six zinc atoms at the vertices of a distorted cube. The crystalline structure of zinc arsenide is very similar to that of cadmium arsenide (Cd<sub>3</sub>As<sub>2</sub>), zinc phosphide (Zn<sub>3</sub>P<sub>2</sub>) and cadmium phosphide (Cd<sub>3</sub>P<sub>2</sub>). These compounds of the Zn-Cd-P-As quaternary system exhibit full continuous solid-solution.
Its lowest direct and indirect bandgaps are within 30 meV of each other.