Zinc selenide

Crystal structure
	__ Zn 2+ __ Se 2−
General
Surname	Zinc selenide
Ratio formula	ZnSe
Brief description	yellow, odorless crystals
External identifiers / databases
EC number	215-259-7
ECHA InfoCard	100,013,873
PubChem	73979
Wikidata	Q204913
properties
Molar mass	144.33 g mol −1
Physical state	firmly
density	5.42 g cm −3
Melting point	> 1100 ° C
solubility	practically insoluble in water
safety instructions
H and P phrases	H: 301-331-373-410
	P: 261-273-301 + 310-311-501
MAK	0.05 mg m −3
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Zinc selenide (ZnSe) is a II-VI compound semiconductor material. The semiconductor crystal does not consist of a pure element , such as. B. silicon , but 1: 1 from stoichiometric amounts of zinc cations (Zn) and selenium anions (Se).

Occurrence

Zinc selenide occurs naturally in the form of the mineral Stilleit .

Extraction and presentation

Zinc selenide can be made by reacting solutions of zinc sulfate and hydrogen selenide .

{\ displaystyle \ mathrm {ZnSO_ {4} + H_ {2} Se \ longrightarrow ZnSe + H_ {2} SO_ {4}}}

It can also be produced by reacting zinc oxide with zinc sulfide and selenium at 800 ° C

{\ displaystyle \ mathrm {2 \ ZnO + ZnS + 3 \ Se \ longrightarrow 3 \ ZnSe + SO_ {2}}}

or by reaction of zinc sulfide with selenium (IV) oxide .

{\ displaystyle \ mathrm {ZnS + SeO_ {2} \ longrightarrow ZnSe + SO_ {2}}}

The hexagonal modification can be obtained by the action of hydrogen selenide on zinc chloride vapor.

properties

Zinc selenide is a lemon yellow powder that is soluble in fuming hydrochloric acid with evolution of hydrogen selenide. Depending on the modification, it has a crystal structure of the zinc blende (a = 5.67 Å ) or wurtzite type (a = 3.98, c = 6.53 Å).

use

ATR measuring crystals for infrared spectroscopy. The yellow crystal in the middle is made of zinc selenide.

Zinc selenide is u. a. used for the production of optically highly reflective surfaces, where it is alternated in thin layers with another substance, e.g. B. Cryolite is evaporated in a vacuum ( multilayer mirror in laser technology ). In addition, unlike normal glass, it is transparent both in the infrared range and in the visible wavelength range . It is therefore particularly suitable for the production of optical windows and focusing lenses for z. B. CO ₂ laser or solid-state laser . The optical properties of the material can be used to transmit the actual processing wavelength , and at the same time enable the transmission of a mostly red semiconductor laser to adjust the beam path .

The infrared transparency of zinc selenide also makes it interesting for use in infrared spectroscopy . The usable spectral range is between 20,000 and 650 cm ⁻¹ (0.5 to 15 µm). In this area, zinc selenide is used as a measuring crystal for the technique of attenuated total reflection (see ATR spectroscopy ). Here the material is also referred to as Irtran-1 . It is considered to be one of the preferred substitutes for the highly toxic thallium bromoiodide (KRS-5) in many routine applications . The refractive index of the two materials is very similar in this area. The refractive index of ZnSe at 1000 cm ⁻¹ is 2.4. However, it is not suitable for use in conjunction with strong acids and bases , as these etch the surface. The same applies to complexing agents such as EDTA and ammonia .

safety instructions

If zinc selenide comes into contact with acids, very poisonous hydrogen selenide gas is released.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g Entry on zinc selenide in the GESTIS substance database of the IFA , accessed on February 20, 2017(JavaScript required) .
↑ Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the indicated labeling it falls under the group entry selenium compounds with the exception of cadmium sulphoselenide and those specified elsewhere in this Annex in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ ^a ^b ^c ^d ^e Georg Brauer (Ed.), With the collaboration of Marianne Baudler u. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 1028.
↑ Rolf Sauer: Semiconductor physics: textbook for physicists and engineers . Oldenbourg Verlag, 2008, ISBN 978-3-486-58863-7 , pp. 402 ( limited preview in Google Book search).
↑ ^a ^b Zinc Selenide (ZnSe). International Crystal Laboratories., Accessed on May 4, 2010 (transmission spectrum of ZnSe in the mid-infrared range).

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g Entry on zinc selenide in the GESTIS substance database of the IFA , accessed on February 20, 2017(JavaScript required) .

[CLP_100.240.771-2] Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the indicated labeling it falls under the group entry selenium compounds with the exception of cadmium sulphoselenide and those specified elsewhere in this Annex in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[brauer-3] Georg Brauer (Ed.), With the collaboration of Marianne Baudler u. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 1028.

[Rolf_Sauer-4] Rolf Sauer: Semiconductor physics: textbook for physicists and engineers . Oldenbourg Verlag, 2008, ISBN 978-3-486-58863-7 , pp. 402 ( limited preview in Google Book search).

[International_Crystal-5] Zinc Selenide (ZnSe). International Crystal Laboratories., Accessed on May 4, 2010 (transmission spectrum of ZnSe in the mid-infrared range).