Gallium (II) selenide

Crystal structure
	__ Ga 2+ __ Se 2−
Crystal system	hexagonal , hP8
General
Surname	Gallium (II) selenide
other names	Gallium monoselenide; Gallium selenide (ambiguous);
Ratio formula	GaSe
Brief description	dark red-brown solid
External identifiers / databases
EC number	234-689-6
ECHA InfoCard	100.031.523
PubChem	6330514
Wikidata	Q3954753
properties
Molar mass	148.7 g mol −1
Physical state	firmly
density	5.03 g cm −3
Melting point	960 ° C
safety instructions
GHS hazard labeling ; no classification available
GHS hazard labeling ; no classification available
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Gallium (II) selenide is an inorganic chemical compound of gallium from the group of selenides . In addition to this, there are other gallium selenides with gallium (III) selenide and gallium (I) selenide .

Extraction and presentation

Gallium (II) selenide can be obtained by reacting gallium with selenium at high temperatures.

{\ displaystyle \ mathrm {Ga + Se \ longrightarrow GaSe}}

properties

Fragments of gallium selenide

Gallium (II) selenide is a dark red-brown solid that is in the form of greasy, shiny leaves and comes in four different modifications. The most common modification has a hexagonal crystal structure (a = 375.5 pm, c = 1594 pm) with the space group P 6 ₃ / mmc (space group no. 194) , which is similar to gallium (II) sulfide . This consists of layers, each layer consisting of Se-Ga-Ga-Se layers, which are connected to one another by covalent bonds. The layers themselves are held together by weak van der Waals bonds. Due to the different arrangement of the layers to each other, the compound crystallizes in several modifications. The compound is a III-VI semiconductor with an indirect band gap of 2.1 eV . The semiconductor changes its electrical conductivity when light falls and is used in the field of non-linear optics in the frequency range from 14 THz to 31 THz for frequency doubling. Template: room group / 194

Because of its optical and electrical properties, the compound has been extensively studied and proposed for a number of applications such as in photovoltaics, lithium batteries, and as nonlinear optical media. However, the practical use of gallium selenide is only possible to a limited extent, since it is technically not easily possible to produce larger single crystals . The practical usability is made more difficult because the material easily breaks along small fault lines in the crystal structure, which makes mechanical processing more difficult. The structural strength can be improved to a certain extent by doping with indium .

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g Georg Brauer , with the assistance of Marianne Baudler u. a. (Ed.): Handbook of Preparative Inorganic Chemistry . 3rd, revised edition. tape I . Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , pp. 860 .
↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
↑ Jane E. Macintyre: Dictionary of Inorganic Compounds . CRC Press, 1992, ISBN 0-412-30120-2 , pp. 3303 ( limited preview in Google Book search).
↑ Roger Blachnik (Ed.): Paperback for chemists and physicists . Volume III: Elements, Inorganic Compounds and Materials, Minerals . founded by Jean d'Ans, Ellen Lax. 4th, revised and revised edition. Springer, Berlin 1998, ISBN 3-540-60035-3 , pp. 466 ( limited preview in Google Book search).
^ ^A ^b Edward D. Palik: Handbook of Optical Constants of Solids . Vol. 3. Academic Press, 1998, ISBN 0-12-544423-0 , pp. 473 ( limited preview in Google Book search).
^ Richard H. Bube, Edward L. Lind: Photoconductivity of Gallium Selenide Crystals . In: Physical Reviews . 115, No. 5, 1959, pp. 1159-1164. doi : 10.1103 / PhysRev.115.1159 .
↑ ^a ^b C. Kübler, R. Huber, S. Tübel, A. Leitenstorfer: Ultrabroadband detection of multi-terahertz field transients with GaSe electro-optic sensors: Approaching the near infrared. In: Applied Physics Letters. 85, 2004, p. 3360, doi : 10.1063 / 1.1808232 .
↑ VG Voevodin, et al .: Large single crystals of gallium selenide: growing, doping by In and characterization . In: Optical Materials . 26, No. 4, 2004, p. 495. doi : 10.1016 / j.optmat.2003.09.014 .
^ Substance Details, Common Chemistry. American Chemical Society, accessed December 13, 2013 .

[brauer-1] ↑ ^a ^b ^c ^d ^e ^f ^g Georg Brauer , with the assistance of Marianne Baudler u. a. (Ed.): Handbook of Preparative Inorganic Chemistry . 3rd, revised edition. tape I . Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , pp. 860 .

[NV-2] This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.

[Jane_E._Macintyre-3] Jane E. Macintyre: Dictionary of Inorganic Compounds . CRC Press, 1992, ISBN 0-412-30120-2 , pp. 3303 ( limited preview in Google Book search).

[Jean_d'._Ans,_Ellen_Lax,_Roger_Blachnik-4] Roger Blachnik (Ed.): Paperback for chemists and physicists . Volume III: Elements, Inorganic Compounds and Materials, Minerals . founded by Jean d'Ans, Ellen Lax. 4th, revised and revised edition. Springer, Berlin 1998, ISBN 3-540-60035-3 , pp. 466 ( limited preview in Google Book search).

[Edward_D._Palik-5] A ^b Edward D. Palik: Handbook of Optical Constants of Solids . Vol. 3. Academic Press, 1998, ISBN 0-12-544423-0 , pp. 473 ( limited preview in Google Book search).

[lind1-6] Richard H. Bube, Edward L. Lind: Photoconductivity of Gallium Selenide Crystals . In: Physical Reviews . 115, No. 5, 1959, pp. 1159-1164. doi : 10.1103 / PhysRev.115.1159 .

[kübler1-7] C. Kübler, R. Huber, S. Tübel, A. Leitenstorfer: Ultrabroadband detection of multi-terahertz field transients with GaSe electro-optic sensors: Approaching the near infrared. In: Applied Physics Letters. 85, 2004, p. 3360, doi : 10.1063 / 1.1808232 .

[voe-8] VG Voevodin, et al .: Large single crystals of gallium selenide: growing, doping by In and characterization . In: Optical Materials . 26, No. 4, 2004, p. 495. doi : 10.1016 / j.optmat.2003.09.014 .

[comchem1-9] Substance Details, Common Chemistry. American Chemical Society, accessed December 13, 2013 .