Zinc arsenide explained

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.^[1]

Synthesis and reactions

Zinc arsenide can be prepared by the reaction of zinc with arsenic

3 Zn + 2 As → Zn₃As₂

Structure

Zn₃As₂ has a room-temperature tetragonal form that converts to a different tetragonal phase at 190 °C and to a third phase at 651 °C.^[2] 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 (Cd₃As₂), zinc phosphide (Zn₃P₂) and cadmium phosphide (Cd₃P₂). These compounds of the Zn-Cd-P-As quaternary system exhibit full continuous solid-solution.^[3]

Electronic structure

Its lowest direct and indirect bandgaps are within 30 meV of each other.^[1]

Notes and References

1. Photoluminescence properties of metalorganic vapor phase epitaxial Zn3As2. Journal of Applied Physics. Botha. J. R.. 86. 5614–5618. Scriven. G. J.. 10. 10.1063/1.371569. 1999. Engelbrecht. J. A. A.. Leitch. A. W. R.. 1999JAP....86.5614B .
2. The As-Zn (arsenic-zinc) system. Journal of Phase Equilibria. Okamoto. H.. 13. 155–161. 2. 1992. 10.1007/BF02667479 . 98798806 .
3. Compounds and solid solutions of the Zn-Cd-P-As system in semiconductor electronics. Inorganic Materials. Trukhan. V. M.. 50. 868–873. Izotov. A. D.. 9. 10.1134/S0020168514090143. 2014. Shoukavaya. T. V.. 94409384 .