Tin(II) sulfide is a chemical compound of tin and sulfur. The chemical formula is SnS. Its natural occurrence concerns herzenbergite (α-SnS), a rare mineral. At elevated temperatures above 905 K, SnS undergoes a second order phase transition to β-SnS (space group: Cmcm, No. 63).[3] In recent years, it has become evident that a new polymorph of SnS exists based upon the cubic crystal system, known as π-SnS (space group: P213, No. 198).[4][5]
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| IUPAC name
Tin(II) sulfide
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| Other names
Tin monosulfide
Herzenbergite | |
| Identifiers | |
3D model (JSmol)
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| ECHA InfoCard | 100.013.863 |
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PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| SnS | |
| Molar mass | 150.775 g/mol |
| Appearance | dark brown solid |
| Density | 5.22 g/cm3 |
| Melting point | 882 °C (1,620 °F; 1,155 K) |
| Boiling point | about 1230 ˚C |
| Insoluble | |
| Structure | |
| GeS type (orthorhombic), oP8 | |
| Pnma, No. 62 | |
a = 11.18 Å, b = 3.98 Å, c = 4.32 Å[2]
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| asymmetric 3-fold (strongly distorted octahedral) | |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
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Irritant |
| Related compounds | |
Other anions
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Tin(II) oxide Tin selenide Tin telluride |
Other cations
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Carbon monosulfide Silicon monosulfide Germanium monosulfide Lead(II) sulfide |
Related compounds
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Tin(IV) sulfide Tributyl tin 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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Synthesis
editIn principle, tin(II) sulfide can be prepared directly from the elements:
- Sn + S → SnS
However, the high-temperature reaction vaporizes sulfur. Consequently effecting the proper stoichiometry is difficult.[6] At near-room temperature in liquid ammonia solution, the same reaction still gives a mixture of 60% stannous and 35% stannic sulfide.[7] Likewise metallic tin contaminates triaryltin sulfide pyrolysates.[7]
At cryogenic temperatures, stannous chloride dissolves in liquid hydrogen sulfide. It then decomposes to the sulfide, but only slowly.[8]
Instead, molten, pure, anhydrous potassium thiocyanate reliably reduces stannic oxide to SnS at 450 °C. An aqueous rinse then removes the potassium sulfide coproduct:[6]
- SnO2 + 2 KSCN → SnS + K2S + 2CO + N2
Properties
editTin(II) sulfide is a dark brown or black solid, insoluble in water, but soluble in concentrated hydrochloric acid. Tin(II) sulfide is insoluble in (NH4)2S. It has a layer structure similar to that of black phosphorus.[9] As per black phosphorus, tin(II) sulfide can be ultrasonically exfoliated in liquids to produce atomically thin semiconducting SnS sheets that have a wider optical band gap (>1.5 eV) compared to the bulk crystal.[10]
Photovoltaic applications
editTin(II) sulfide is an interesting potential candidate for next generation thin-film solar cells. Currently, both cadmium telluride and CIGS (copper indium gallium selenide) are used as p-type absorber layers, but they are formulated from toxic, scarce constituents.[11] Tin(II) sulfide, by contrast, is formed from cheap, earth abundant elements, and is nontoxic. This material also has a high optical absorption coefficient, p-type conductivity, and a mid range direct band gap of 1.3-1.4 eV, required electronic properties for this type of absorber layer.[12] Based on the a detailed balance calculation using the material bandgap, the power conversion efficiency of a solar cell utilizing a tin(II) sulfide absorber layer could be as high as 32%, which is comparable to crystalline silicon.[13] Finally, Tin(II) sulfide is stable in both alkaline and acidic conditions.[14] All aforementioned characteristics suggest tin(II) sulfide as an interesting material to be used as a solar cell absorber layer.
At present, tin(II) sulfide thin films for use in photovoltaic cells are still in the research phase of development with power conversion efficiencies currently less than 5%.[15] Barriers for use include a low open circuit voltage and an inability to realize many of the above properties due to challenges in fabrication, but tin(II) sulfide still remains a promising material if these technical challenges are overcome.[13]
References
edit- ^ Record of Tin(II) sulfide in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 4/9/2007.
- ^ del Bucchia, S.; Jumas, J.C.; Maurin, M. (1981). "Contribution a l'etude de composes sulfures d'etain (II): Affinement de la structure de Sn S". Acta Crystallogr. B. 37 (10): 1903. Bibcode:1981AcCrB..37.1903D. doi:10.1107/s0567740881007528.
- ^ Wiedemeier, Heribert; von Schnering, Hans Georg (1978-01-01). "Refinement of the structures of GeS, GeSe, SnS and SnSe : Zeitschrift für Kristallographie". Zeitschrift für Kristallographie. 148 (3–4): 295–303. doi:10.1524/zkri.1978.148.3-4.295. S2CID 53314748.
- ^ Rabkin, Alexander; Samuha, Shmuel; Abutbul, Ran E.; Ezersky, Vladimir; Meshi, Louisa; Golan, Yuval (2015-03-11). "New Nanocrystalline Materials: A Previously Unknown Simple Cubic Phase in the SnS Binary System". Nano Letters. 15 (3): 2174–2179. Bibcode:2015NanoL..15.2174R. doi:10.1021/acs.nanolett.5b00209. ISSN 1530-6984. PMID 25710674.
- ^ Abutbul, R. E.; Segev, E.; Zeiri, L.; Ezersky, V.; Makov, G.; Golan, Y. (2016-01-12). "Synthesis and properties of nanocrystalline π-SnS – a new cubic phase of tin sulphide". RSC Advances. 6 (7): 5848–5855. Bibcode:2016RSCAd...6.5848A. doi:10.1039/c5ra23092f. ISSN 2046-2069.
- ^ a b Baudler, M. (1963) [1960]. "Tin and lead". In Brauer, Georg (ed.). Handbook of Preparative Inorganic Chemistry. Vol. 1. Translated by Riley, Reed F. (2nd ed.). New York: Academic. pp. 739–740. LCCN 63-14307.
- ^ a b Price, Louise S.; Parkin, Ivan P.; Field, Mark N.; Hardy, Amanda M. E.; Clark, Robin J. H.; Hibbert, Thomas G.; Molloy, Kieran C. (27 Jan 2000) [4 Oct 1999]. "Atmospheric pressure chemical vapour deposition of tin(II) sulfide films on glass substrates from Bun
3SnO2CCF3 with hydrogen sulfide". Journal of Materials Chemistry. 10 (2): 527. doi:10.1039/a907939d – via CiteSeerX. - ^ Quam, G. N. (8 Jan 1925) [5 Sept 1924]. "A study of reactions in liquid hydrogen sulfide". Journal of the American Chemical Society. 47: 105–106. doi:10.1021/ja01678a014. (Excerpted from a PhD thesis at Iowa State College.) "The chlorides of tin and phosphorus were all soluble, and slow decomposition resulted in the formation of the respective sulfides." See also Table 1, wherein "Stannous chloride" and "Stannic chloride" are both listed as "Soluble and reactive".
- ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1233. ISBN 978-0-08-037941-8.
- ^ Brent; et al. (2015). "Tin(II) Sulfide (SnS) Nanosheets by Liquid-Phase Exfoliation of Herzenbergite: IV–VI Main Group Two-Dimensional Atomic Crystals". J. Am. Chem. Soc. 137 (39): 12689–12696. doi:10.1021/jacs.5b08236. PMID 26352047.
- ^ Ginley, D.; Green, M.A. (2008). "Solar energy conversion towards 1 terawatt". MRS Bulletin. 33 (4): 355–364. doi:10.1557/mrs2008.71.
- ^ Andrade-Arvizu, Jacob A.; Courel-Piedrahita, Maykel; Vigil-Galán, Osvaldo (2015-04-14). "SnS-based thin film solar cells: perspectives over the last 25 years". Journal of Materials Science: Materials in Electronics. 26 (7): 4541–4556. doi:10.1007/s10854-015-3050-z. ISSN 0957-4522. S2CID 137524157.
- ^ a b Nair, P. K.; Garcia-Angelmo, A. R.; Nair, M. T. S. (2016-01-01). "Cubic and orthorhombic SnS thin-film absorbers for tin sulfide solar cells". Physica Status Solidi A. 213 (1): 170–177. Bibcode:2016PSSAR.213..170N. doi:10.1002/pssa.201532426. ISSN 1862-6319. S2CID 124780995.
- ^ Sato, N.; Ichimura, E. (2003). "Characterization of electrical properties of SnS thin films prepared by the electrochemical deposition method". Proceedings of 3rd World Conference on Photovoltaic Energy Conversion. A.
- ^ Jaramillo, R.; Steinmann, V.; Yang, C.; Chakraborty, R.; Poindexter, J. R. (2015). "Making Record-efficiency SnS Solar Cells by Thermal Evaporation and Atomic Layer Deposition". J. Vis. Exp. (99): e52705. doi:10.3791/52705. PMC 4542955. PMID 26067454.