Indium(III) sulfide

Indium(III) sulfide

Names
Other names indium sesquisulfide, diindium trisulphide
Identifiers
CAS Number	12030-24-9 N
3D model (Jmol)	Interactive image
ChemSpider	17617491 Y
ECHA InfoCard	100.031.571
PubChem	160966
InChI InChI=1S/2In.3S Y Key: ZOMNDSJRWSNDFL-UHFFFAOYSA-N Y InChI=1/2In.3S/rIn2S3/c3-1-5-2-4 Key: ZOMNDSJRWSNDFL-YYMIQOPKAJ
SMILES S=[In]S[In]=S
Properties
Chemical formula	In2S3
Molar mass	325.82 g/mol
Appearance	red powder
Density	4.90 g/cm3, solid
Melting point	1,050.0 °C (1,922.0 °F; 1,323.2 K)
Solubility in water	insoluble
Hazards
EU classification (DSD)	not listed
NFPA 704	4 3 2
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Indium(III) sulfide is the inorganic compound with the formula In₂S₃. Three different structures ("polymorphs") are known: yellow, α-In₂S₃ has a defect cubic structure, red β-In₂S₃ has a defect spinel, tetragonal, structure, and γ-In₂S₃ has a layered structure. The red, β, form is considered to be the most stable form at room temperature, although the yellow form may be present depending on the method of production. Like related covalent solids, In₂S₃ is insoluble in all solvents. It is attacked by acids and by sulfide. It is slightly soluble in Na₂S.

Indium sulfide was the first indium compound ever described, being reported in 1863. Reich and Richter determined the existence of indium as a new element from the sulfide precipitate.

In₂S₃ features tetrahedral In(III) centers linked to four sulfido ligands. β-In₂S₃ is a diamagnetic, n-type semiconductor with an optical band gap of 2.1 eV. It has been proposed to replace the hazardous cadmium sulfide, CdS, as a buffer layer in solar cells.

Indium sulfide is usually prepared by direct combination of the elements. Production from volatile complexes of indium and sulfur, for example dithiocarbamates (e.g. Et₂In^IIIS₂CNEt₂), has been explored for vapor deposition techniques.