Germanium monoselenide

"GeSe" redirects here. For other uses, see Gese (disambiguation).
Germanium monoselenide
Names
IUPAC name
Germanium selenide
Other names
germanium(II) selenide
Identifiers
ECHA InfoCard 100.031.862 Edit this at Wikidata
Properties
GeSe
Molar mass 151.57 g/mol
Appearance black
Density 5.56 g/cm3
Melting point 667 °C (1,233 °F; 940 K) (decomposes)
Band gap 1.33 eV (direct) [1]
2.5
Structure
Orthorhombic
Pnma
Related compounds[2]
Other anions
 Germanium monoxide
Germanium monosulfide
Germanium telluride
Other cations
 Tin selenide
Lead selenide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Germanium monoselenide is a chemical compound with the formula GeSe. It exists as black crystalline powder having orthorhombic (distorted NaCl-type) crystal symmetry; at temperatures ~650 °C, it transforms into the cubic NaCl structure.[3] GeSe has been shown to have stereochemically active Ge 4s lone pairs that are responsible for the distorted structure and the relatively high position of the valence band maximum with respect to the vacuum level.[4]

To grow GeSe crystals, GeSe powder is vaporized at the hot end of a sealed ampule and allowed to condense at the cold end. Usual crystals are small and show signs of irregular growth, caused mainly by convective motion in the gaseous medium. However, GeSe grown under condition of zero-gravity and reduced convection aboard the Skylab are ~10 times larger than Earth-grown crystals, and are free from visual defects.[5][6]

  1. ^ Philip A. E. Murgatroyd, Matthew J. Smiles, Christopher N. Savory, Thomas P. Shalvey, Jack E. N. Swallow, Nicole Fleck, Craig M. Robertson, Frank Jäckel, Jonathan Alaria, Jonathan D. Major, David O. Scanlon, and Tim D. Veal; et al. (2020). "GeSe: Optical Spectroscopy and Theoretical Study of a van der Waals Solar Absorber". Chemistry of Materials. 32 (7): 3245–3253. doi:10.1021/acs.chemmater.0c00453. PMC 7161679. PMID 32308255.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  2. ^ GeSe at webelements
  3. ^ Wiedemeier H., Siemers P.A. (1975). "The Thermal Expansion and High Temperature Transformation of GeSe". Zeitschrift für anorganische und allgemeine Chemie. 411: 90–96. doi:10.1002/zaac.19754110110.
  4. ^ M. J. Smiles, J. M. Skelton, H. Shiel, L. A. H. Jones, J. E. N. Swallow, H. J. Edwards, T. J. Featherstone, P. A. E. Murgatroyd, P. K. Thakur, Tien-Lin Lee, V. R. Dhanak, and T. D. Veal; et al. (2021). "Ge 4s2 Lone Pairs and Band Alignments in GeS and GeSe for photovoltaics". J. Mater. Chem. A. 9 (39): 22440–22452. doi:10.1039/D1TA05955F. hdl:10023/24142.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  5. ^ "SP-400 Skylab, Our First Space Station". NASA. Retrieved 2009-06-06.
  6. ^ H. Wiedemeier; et al. (1975). "Crystal growth and transport rates of GeSe and GeTe in micro-gravity environment". Journal of Crystal Growth. 31: 36. Bibcode:1975JCrGr..31...36W. doi:10.1016/0022-0248(75)90107-4.