تلوريد الزرنيخ الثلاثي

تلوريد الزرنيخ الثلاثي

المُعرِّفات
رقم CAS
3D model (JSmol)	Interactive image
ChemSpider	22797844
ECHA InfoCard	100.031.765
رقم EC	234-955-1
PubChem CID	6336551
CompTox Dashboard (EPA)	DTXSID001014262
InChI InChI=1S/2As.3Te Key: KOOQXSDVIQPGQD-UHFFFAOYSA-N
SMILES [As].[As].[Te].[Te].[Te]
الخصائص
الصيغة الجزيئية	As2Te3
كتلة مولية	532.64 g mol-1
البنية
البنية البلورية	Monoclinic
الزمرة الفراغية	C2/m
ثابت العقد	a = 14.339 Å, b = 4.006 Å, c = 9.873 Å
ثابت العقد	α = 90°, β = 95°, γ = 90°
المخاطر
ن.م.ع. مخطط تصويري
ن.م.ع. كلمة الاشارة	Danger
ن.م.ع. عبارات المخاطر	H301, H331, H410
ن.م.ع. العبارات الاحتياطية	P261, P264, P270, P271, P273, P301+P310, P304+P340, P311, P321, P330, P391, P403+P233, P405, P501
مركبات ذا علاقة
أنيونات أخرى	Arsenic trioxide Arsenic trisulfide Arsenic triselenide
كاتيونات أخرى	Antimony telluride Bismuth telluride
ما لم يُذكر غير ذلك، البيانات المعطاة للمواد في حالاتهم العيارية (عند 25 °س [77 °ف]، 100 kPa).
مراجع الجدول

Arsenic(III) telluride is an inorganic compound with the chemical formula As
2Te
3. 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.

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 Molecular and crystal structure

Arsenic(III) telluride is a bulk formقالب:Cln of group 15 sesquichalcogenidesقالب:Cln which form chains of As
2Te
3 molecules that are eventuallyقالب:Cln stacked on top of each other and held together by weak Van der Waals forces. This stacking of long branches of As
2Te
3 molecules gives arsenic(III) telluride an amorphous crystallineقالب:Cln structure that can be found in the ɑ-As
2Te
3 and β-As
2Te
3 configurations at different pressures. At ambient pressure, ɑ-As
2Te
3 yields a monoclinic structure with low thermoelectric properties; however, when placed in high pressure environments, ɑ-As
2Te
3 transforms into the β-As
2Te
3 configuration that has a rhombohedral R3m space group with high thermoelectric properties.قالب:Cln

As
2Te
3 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 impuritiesقالب:Which? 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 As
2Te
3 forming impurity clusters which causes an increase in paramagnetic tendency of the complex.قالب:Huh

 Applications in nonlinear optics

As
2Te
3 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 As
2Te
3 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 As
2Te
3 containing materials are starting to increase in popularity in the field of nonlinear optics because the amorphous glasses As
2Te
3 is exceptional at redistributing the electrical charge density of the light source (typically a laser) 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 As
2Te
3 presents mobility edges, which are edges surrounding a conductive gap,قالب:Huh 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.

 Semiconductor

Arsenic(III) telluride, in its doped crystalline form, houses electron carriers that are caused by doping impurities that sit close to the edge due to the relatively free electron density around the edges. These relatively free electrons interact with the impurities causing a decrease in electron density around the edge which causes a “tail” to form. These band tails overlap causing a gap or a hole, similar to p-type doping, that can be used for conduction; however, the mobility of the carriers in the lattice decreases significantly near the Fermi level of the two tails. This indicates that electronic stimuli, usually phonon related, is needed to induce hopping of electrons into the gap to cause conduction. The need of external phonon stimuli to cause electrical conductivity of As
2Te
3 crystals further supports the effectiveness of As
2Te
3 or As
2Te
3 based glasses in the use of nonlinear optics because the light upon entering the lattice causes the electron hopping inducing conduction. Since the electrons are hopping into the conductance gap near the Fermi level, the light is being modified and will exit the lattice in a different form than it entered.