Gallium Selenide (GaSe)-Granules

Characteristic




Gallium(II) selenide (GaSe) is a chemical compound. It has a hexagonal layer structure, similar to that of GaS. It is a photoconductor, a second harmonic generation crystal in nonlinear optics, and has been used as a far-infrared conversion material at 14-31 THz and above.




Chemical formula：GaSe

Molar mass：148.69 g/mol

Appearance：brown solid

Density：5.03 g/cm3

Melting point：960 °C (1,760 °F; 1,230 K)

Band gap：2.1 eV (indirect)

Refractive index (nD)：2.6

Crystal structure：hexagonal, hP8




Application




It is said to have potential for optical applications but the exploitation of this potential has been limited by the ability to readily grow single crystals Gallium selenide crystals show great promise as a nonlinear optical material and photoconductor. 




Several methods of frequency conversion using non-linear optical materials exist. Second harmonic generation leads to doubling of the frequency of infrared carbon dioxide lasers. 




Single layers of gallium selenide are dynamically stable two-dimensional semiconductors, in which the valence band has an inverted Mexican-hat shape, leading to a Lifshitz transition as the hole-doping is increased.