Zinc arsenide (Zn₃As₂) is a

binary compound In materials chemistry, a binary phase or binary compound is a chemical compound containing two different elements. Some binary phase compounds are molecular, e.g. carbon tetrachloride (CCl4). More typically binary phase refers to extended soli ...

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

with

arsenic Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, b ...

which forms gray

tetragonal In crystallography, the tetragonal crystal system is one of the 7 crystal systems. Tetragonal crystal lattices result from stretching a cubic lattice along one of its lattice vectors, so that the cube becomes a rectangular prism with a squar ...

crystals. It is an

inorganic In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemist ...

semiconductor A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way ...

with a

band gap In solid-state physics, a band gap, also called an energy gap, is an energy range in a solid where no electronic states can exist. In graphs of the electronic band structure of solids, the band gap generally refers to the energy difference ( ...

of 1.0 eV.

Synthesis and reactions

Zinc arsenide can be prepared by the reaction of

with

:3 Zn + 2 As → Zn₃As₂

Structure

Zn₃As₂ has a room-temperature

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 (Cd₃As₂), zinc phosphide (Zn₃P₂) and cadmium phosphide (Cd₃P₂). 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 or each other.

References

arsenide In chemistry, an arsenide is a compound of arsenic with a less electronegative element or elements. Many metals form binary compounds containing arsenic, and these are called arsenides. They exist with many stoichiometries, and in this respect a ...

II-V semiconductors II-V compounds Soviet chemical weapons program {{inorganic-compound-stub