Gallium(II) sulfide
Names

Other names Gallium sulfide^{[citation needed]}
Identifiers
CAS Number	12024-10-1^Y
3D model (JSmol)	Interactive image
ChemSpider	4898760^N
ECHA InfoCard	100.031.522
PubChem CID	6370242
CompTox Dashboard (EPA)	DTXSID101319005
InChI InChI=1S/Ga.S^N Key: HLVRMBHKGAMNOI-UHFFFAOYSA-N^N
SMILES [Ga+2][Ga+2].[S-2].[S-2]
Properties
Chemical formula	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)
Magnetic susceptibility (χ)	−-23.0·10⁻⁶ cm³/mol
Structure
Crystal structure	hexagonal, hP8
Space group	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). N verify (what is ^YN ?) 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 Ga^tBu₂(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]

Gallium(II) sulfide demonstrates nonlinear optical activities, including second-harmonic generation and two-photon excited fluorescence.^[4]

References

[edit]

^ ^a ^b Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
^ 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
^ 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 (19): 195403. arXiv:1302.6067. Bibcode:2013PhRvB..87s5403Z. doi:10.1103/PhysRevB.87.195403.
^ Safayet Ahmed, Ping Kwong Cheng, Junpeng Qiao, Wei Gao, Ahmed Mortuza Saleque, Md. Nahian Al Subri Ivan, Ting Wang, Tawsif Ibne Alam, Sumaiya Umme Hani, Zong Liang Guo, Siu Fung Yu, and Yuen Hong Tsang (2022). "Nonlinear Optical Activities in Two-Dimensional Gallium Sulfide: A Comprehensive Study". ACS Nano. 16 (8): 12390–12402. doi:10.1021/acsnano.2c03566. hdl:10397/99690. PMID 35876327.((cite journal)): CS1 maint: multiple names: authors list (link)