Zinc arsenide (Zn3As2) 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.
Synthesis and reactions
Zinc arsenide can be prepared by the reaction of
zinc with
arsenic
- 3 Zn + 2 As → Zn3As2
Structure
Zn
3As
2 has a room-temperature tetragonal form that converts to a different tetragonal phase at 190 °C and to a third phase at 651 °C.
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,
zinc phosphide and cadmium phosphide (Cd
3P
2). These compounds of the Zn-Cd-P-As quaternary system exhibit full continuous solid-solution.
Electronic structure
Its lowest direct and indirect bandgaps are within 30 meV of each other.
