Tin selenide
| Names | |
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| Other names
Tin(II) selenide
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| Identifiers | |
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3D model (JSmol)
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| ECHA InfoCard | 100.013.871 |
| EC Number | 215-257-6 |
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PubChem CID
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| Properties | |
| SnSe | |
| Molar mass | 197.67 g/mol |
| Appearance | steel gray odorless powder |
| Density | 6.179 g/cm3 |
| Melting point | 861 °C (1,582 °F; 1,134 K) |
| negligible | |
| Band gap | 0.9 eV (indirect), 1.3 eV (direct) |
| Structure | |
| Orthorhombic, oP8 | |
| Pnma, No. 62 | |
| Thermochemistry | |
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Std enthalpy of
formation (ΔfH |
-88.7 kJ/mol |
| Hazards | |
| Safety data sheet | https://www.ltschem.com/msds/SnSe.pdf |
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EU classification (DSD) (outdated)
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Toxic (T) Dangerous for the environment (N) |
| R-phrases (outdated) | R23/25, R33, R50/53 |
| S-phrases (outdated) | (S1/2), S20/21, S28, S45, S60, S61 |
| NFPA 704 | |
| Related compounds | |
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Other anions
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Tin(II) oxide Tin(II) sulfide Tin telluride |
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Other cations
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Carbon monoselenide Silicon monoselenide Germanium selenide Lead selenide |
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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 (what is   ?) |
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| Infobox references | |
Tin selenide, also known as stannous selenide, is an inorganic compound with the formula (SnSe), where Tin has a +2 oxidation state. Tin(II) selenide is a narrow band-gap (IV-VI) semiconductor and has received considerable interest for applications including low-cost photovoltaics and memory-switching devices. Tin(II) selenide is a typical layered metal chalcogenide; that is, it includes a Group 16 anion (Se2−) and an electropositive element (Sn2+), and it is arranged in a layered structure.
Tin(II) selenide exhibits low thermal conductivity as well as reasonable electrical conductivity, creating the possibility of it being used in thermoelectric materials. In 2014, a team at Northwestern University has established the world record performance for thermoelectric material efficiency.
Tin(II) selenide (SnSe) has stiff bonds and distorted lattice, crystallizing in the orthorhombic GeSe (germanium selenide) structure. To be isomorphous, two substances must have the same chemical formulation, and they must contain atoms with corresponding chemical properties and with similar atomic radii. Tin(II) selenide exists in a doubled layered structure that derives from a distorted rock-salt structure. Within these double layers, each tin atom is covalently bonded to three neighboring selenide (Se) atoms, and each selenide atom is covalently bonded to three neighboring tin atoms. The double layers are then held together primarily by van der Waals forces.
Tin(II) selenide’s layered structure bestows both anharmonic and anisotropic bonding to the compound.
At pressures above 58 GPa, SnSe acts as a superconductor; this change of conductivity is likely due to a change in the structure to that of a CsCl structure.
Tin(II) selenide can be formed by reacting the elements tin and selenium above 350 °C.
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