Gallium(II) sulfide

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Gallium(II) sulfide
Ball and stick, cell model of gallium(II) sulfide
Names
Other names
Gallium sulfide[citation needed]
Identifiers
3D model (Jmol)
ChemSpider
ECHA InfoCard 100.031.522
Properties
GaS
Molar mass 101.788 g mol−1
Appearance Yellow crystals
Density 3.86 g cm−3
Melting point 965 °C (1,769 °F; 1,238 K)
−-23.0·10−6 cm3/mol
Structure
hexagonal, hP8
P63/mmc, No. 194
Related compounds
Related compounds
Gallium(III) sulfide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Gallium(II) sulfide, GaS, is a chemical compound of gallium and sulfur. The normal form of gallium(II) sulfide as made from the elements has a hexagonal layer structure containing Ga24+ units which have a Ga-Ga distance of 248pm.[1] This layer structure is similar to GaTe, GaSe and InSe.[1] An unusual metastable form, with a distorted wurtzite structure has been reported as being produced using MOCVD. The metal organic precursors were di-tert-butyl gallium dithiocarbamates, for example GatBu2(S2CNMe2) and this was deposited onto GaAs. The structure of the GaS produced in this way is presumably Ga2+ S2−.[2]

Single layers of gallium sulfide are dynamically stable two-dimensional semiconductors, in which the valence band has an inverted Mexican-hat shape, leading to a Lifshitz transition as the hole-doping is increased.[3]

References[edit]

WebElements

  1. ^ a b Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0-08-037941-9. 
  2. ^ MOCVD Growth of Gallium Sulfide Using Di-tert-butyl Gallium Dithiocarbamate Precursors: Formation of a Metastable Phase of GaS A. Keys, S G. Bott, A. R. Barron Chem. Mater., 11 (12), 3578 -3587, 1999. doi:10.1021/cm9903632
  3. ^ V. Zolyomi, N. D. Drummond and V. I. Fal'ko (2013). "Band structure and optical transitions in atomic layers of hexagonal gallium chalcogenides". Phys. Rev. B. 87: 195403. doi:10.1103/PhysRevB.87.195403.