Arsenic(III) telluride
Arsenic telluride is an inorganic compound of arsenic and tellurium with the chemical formula. It exists in two forms, the monoclinic α phase which transforms under high pressure to a rhombohedral β phase. The compound is a semiconductor, with most current carried by holes. Arsenic telluride has been examined for its use in nonlinear optics.
Molecular and crystal structure
Arsenic telluride is a bulk form of group 15 sesquichalcogenides which form chains of molecules that are eventually stacked on top of each other and held together by weak Van der Waals forces. This stacking of long branches of molecules gives arsenic telluride an amorphous crystalline structure that can be found in the ɑ- and β- configurations at different pressures. At ambient pressure, ɑ- yields a monoclinic structure with low thermoelectric properties; however, when placed in high pressure environments, ɑ- transforms into the β- configuration that has a rhombohedral R3''m'' space group with high thermoelectric properties.is a semiconductor and has been used to study nonlinear optics due to its ability to conduct electrical current; however, at high temperatures when doped with impurities causes these conductive abilities to transform irreversibly from its traditional semiconductor ability to metal conduction only. This irreversible transformation is most likely caused by the doping materials added to forming impurity clusters which causes an increase in paramagnetic tendency of the complex.
Applications in nonlinear optics
is the least studied amorphous chalcogenide compound, which are a group of semiconductors primarily used in nonlinear optics as glasses or lenses to redistribute light. It has not been studied widely due to the difficulty to synthesize into amorphous crystalline solids. In order to avoid crystalizing arsenic telluride, it must be quenched quickly after it comes out of the melt. Arsenic telluride and containing materials are starting to increase in popularity in the field of nonlinear optics because the amorphous glasses is exceptional at redistributing the electrical charge density of the light source when it interacts within the medium. The significance of this redistribution is that it allows for the modification of the laser’s nature to perform a specific function. Some examples of this are the use of lasers in sensors, optical communication systems, as well as changing the color of the laser for equipment and other machinery used in materials research.It has also been discovered in recent studies that presents mobility edges, which are edges surrounding a conductive gap, regardless of temperature allowing for the amorphous structure to conduct electricity at greater rates than expected. Due to this, it can be hypothesized that the mobility edges lie between delocalized and localized states as well as having a more energetically efficient transition from dark mobility to photoconductive mobility than other amorphous glasses.