Indium(III) sulfide

Indium(III) sulfide
Other names indium sesquisulfide, diindium trisulphide
Identifiers
CAS number	12030-24-9
PubChem	16685236
ChemSpider	17617491 Y
Jmol-3D images	Image 1
SMILES S=[In]S[In]=S
InChI InChI=1S/2In.3S Y Key: ZOMNDSJRWSNDFL-UHFFFAOYSA-N Y InChI=1/2In.3S/rIn2S3/c3-1-5-2-4 Key: ZOMNDSJRWSNDFL-YYMIQOPKAJ
Properties
Molecular formula	In2S3
Molar mass	325.82 g/mol
Appearance	red powder
Density	4.90 g/cm³, solid
Melting point	1050.0 °C
Solubility in water	insoluble
Hazards
EU classification	not listed
NFPA 704	4 3 2
Y sulfide (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
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.^[1]

Indium sulfide was the first indium compound ever described, being reported in 1863.^[2] Reich and Richter determined the existence of indium as a new element from the sulfide precipitate.

Structure and properties

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.^[3]

Production

Traditionally it was prepared in the chemical laboratory by direct combination of the elements. Production from volatile complexes of indium and sulfur for example dithiocarbamates (e.g. Et₂In^IIIS₂CNEt₂) have been explored as methods suitable for vapor deposition techniques.^[4]

General references

• WebElements
• Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Oxford: Butterworth-Heinemann. ISBN 0080379419. 

References

1. ^ Indium Sulfide
2. ^ F. Reich, Th. Richter (1863). "Vorläufige Notiz über ein neues Metall". J. Prakt. Chem. 89: 441. doi:10.1002/prac.18630890156. 
3. ^ N. Barreau, S. Marsillac, D. Albertini and J. C. Bernede (2002). "Structural, optical and electrical properties of β-In2S3-3xO3x thin films obtained by PVD". Thin Solid Films 403: 331–334. doi:10.1016/S0040-6090(01)01512-7. 
4. ^ S. W. Haggata M Azad Malik, M. Motevalli, and P. O'Brien (1995). "Synthesis and Characterization of Some Mixed Alkyl Thiocarbamates of Gallium and Indium, Precursors for III/VI Materials: The X-ray Single-Crystal Structures of Dimethyl- and Diethylindium Diethyldithiocarbamate". Chem. Mater. 7 (4): 716–724. doi:10.1021/cm00052a017.