Селенид галлия (Ga2Se3)

Description

Gallium selenide Ga2Se3 (gallium sesquiselenide, digallium triselenide) is an inorganic salt in which gallium is in the +3 oxidation state, in contrast to the layered monoselenide GaSe. Belongs to the category of non-metallic minerals and inorganic compounds of gallium and selenium.

Identification

• English name: Gallium selenide (Ga2Se3)
• CAS No.: 12024-24-7
• Chemical formula: Ga2Se3
• Synonyms: Digallium triselenide, Gallium sesquiselenide, Gallium selenide (3+)

Physico-chemical characteristics

• Molecular weight: 376.33
• Appearance: Solid crystalline substance
• Density: 4.83 g/cm3
• Melting point: 1020 °C
• XLogP3: -1.454

Class of substance and properties

Ga2Se3 is a stoichiometric gallium(III) salt; unlike the related layered monoselenide GaSe, it does not have a van der Waals structure with a direct Ga–Ga bond. Crystallizes in the form characteristic of semiconductor compounds of the A2III B3VI type, and is used as an alternative source of gallium and selenium in materials science research, complementing the more common binary monoselenide GaSe and allowing comparison of the behavior of gallium in different oxidation states in the same selenide series.

Scope of application

It is used as a precursor for the production of other gallium selenides and compounds, as well as in the research of semiconductor and photovoltaic materials based on gallium and selenium. Like the related Ga2S3, it serves as a source of Ga3+ and Se2- in inorganic synthesis.

Safety Information

• Packing level: III
• Transport codes: 3077
• Hazard class code: 9

Storage and transportation

Store in a sealed container in a dry place, away from moisture and acids, transport according to hazard class 9 (other hazardous substances), packaging group III.

Crystal structure

Compounds of the general composition III2VI3, which include Ga2Se3, usually crystallize in structures of the defective zinc blend type: the cation lattice positions are not completely filled with gallium, and the remaining vacancies are ordered in a certain way. This ordered vacancy structure brings Ga2Se3 closer to related compounds of the same structural class - In2Se3 and Al2Se3 - and determines its electronic and optical properties, which are different from the properties of binary monoselenide GaSe.

Relationship with sesquisulfide Ga2S3

In terms of the stoichiometry and valency of gallium, Ga2Se3 is a direct analogue of Ga2S3, differing only in the nature of the chalcogen. Replacing sulfur with the larger, less electronegative selenium lowers the melting point and changes the crystal lattice parameters, which is typical of transitions within one structural family of inorganic gallium compounds. This comparison helps predict the behavior of less studied gallium selenides by analogy with more fully characterized sulfides of the same series.