Gallium(II) selenide (Ga Se ) 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.    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 .    Non-linear optical materials are used in the frequency conversion  of laser light .    Frequency conversion involves the shifting of the wavelength of a monochromatic source of light, usually laser light, to a higher or lower wavelength of light that cannot be produced from a conventional laser source.
 
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 .    In optical parametric generation, the wavelength of light is doubled.    Near-infrared solid-state lasers  are usually used in optical parametric generations.
 
One original problem with using gallium selenide in optics is that it is easily broken along cleavage lines and thus it can be hard to cut for practical application.    It has been found, however, that doping  the crystals with indium  greatly enhances their structural strength and makes their application much more practical.    There remain, however, difficulties with crystal growth that must be worked out before gallium selenide crystals may become more widely used in optics.
 
■  General Properties
Molar mass Appearance Density Melting
point
Band gap Electron Mobility Crystal
structure
148.69 g/mol brown solid 5.03 g/cm3 960 °C,
1233 K,
1760 °F
2.1 eV (indirect )
2.6
1600 cm2 V-1 s-1 (0 K)
6000 cm2 V-1 s-1 (300 K)
Hexagonal
 
조건별 검색

검색