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Cadmium
Telluride (CdTe) |
 Cadmium
telluride (CdTe) is an excellent semiconductor for solar cells because
its bandgap of 1.4 electron-volts is matched nearly perfectly to the
solar spectrum. The device structure also includes a very thin layer
of cadmium sulfide that allows most sunlight to pass through to the CdTe
layer. These characteristics provide the potential for high-efficiency
modules with low-cost manufacturing processes. CdTe is transparent from
close to its band gap energy out to infrared wavelengths greater than
20 ¦Ìm. The refractive index is 2.649 at 10¦Ìm. CdTe has very low solubility
in water. It is etched by many acids including hydrochloric, and hydrobromic
acid, forming (toxic) hydrogen telluride gas.
 CdTe is a useful material
for solar cells (photovoltaics). CdTe can be alloyed with mercury to
make a versatile infrared
detector material (HgCdTe). CdTe alloyed with a small amount of zinc
makes an excellent solid-state x-ray and
gamma ray detector (CdZnTe).
CdTe is used as an infrared optical
material for optical
windows and lenses.
CdTe is also applied for electrooptical modulators. It has highest electrooptical coefficient of the linear electrooptic effect among II-VI compound crystals (r41=r52=r63=6.8*10-12 m/V).
Cadmium telluride is commercially available as a powder, or as crystals.
It can be made into nanocrystals.
Basic Information
- Molecular weight: 240.02
- Density: 5850 kg/m3.
- Lattice constant: 0.648 nm at 300K
- Young's modulus: 52 GPa
- Poisson ratio: 0.41
- The direct band gap is 1.56 eV at 300 K.
- Electron effective mass 0.11 me
- Hole effective mass 0.4 me
- Melting Point: 1314 K
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- Thermal conductivity: 6.2 W.m-1.K-1 at 293 K
- Specific heat capacity: 210 J.kg-1.K-1 at 293 K
- Thermal expansion coefficient: 5.9x10-6 K-1 at 293
- The direct band gap is 1.56 eV at 300 K.
- Electron effective mass 0.11 me
- Hole effective mass 0.4 me
- CdTe is transparent in the infrared, from close to its band gap energy (=795nm) out to wavelengths greater than 20 ¦Ìm. The refractive index is 2.649 at 10¦Ìm.
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Cadmium Telluride Sputtering Target(CdTe target)
Purity--- 99.99%,99.999%, 99.9995%
Shape---Disks, Sheets,Plate,custom-made
Size ---Discs: Dia(¡Ü360mm),Thickness(¡Ý0.5mm)
Rectangle: Length(¡Ü250mm),Width(¡Ü250mm),Thickness(¡Ý1mm)
Rods: Dia(¡Ü250mm),Length(¡Ü250mm)
Pellets: Dia(¡Ü250mm),Thickness(¡Ý1mm)
Application
--- Primary used solar cells... CdTe target. |
Cadmium
Telluride Granuale (CdTe evaporation material)
Purity
--- 99.99%,99.999%, 99.9995% Shape
--- granuale(1-12mm)
Application
--- Primary used solar cells... |
Cadmium
Telluride (CdTe) Powders
Purity
--- 99.99%,99.999%, 99.9995% Shape
--- Powder,
200-300 mesh, custom-made
Application
--- Primary used solar cells... |
Toxicity
Cadmium telluride is toxic. It should not be ingested, nor its dust inhaled, and it should not be handled without appropriate gloves and other safety precautions. Please refer to materials safety data sheets for details.
The toxicity is not solely due to the cadmium content. One study found that the highly reactive surface of cadmium telluride quantum dots triggers extensive reactive oxygen damage to the cell membrane, mitochondria, and cell nucleus. In addition, the cadmium telluride devices are typically dipped in a toxic compound of cadmium sulfide.
The disposal life-cycle and long term safety of cadmium telleride is becoming more of a known issue in the large scale commercialization of cadmium telluride solar panels. A document hosted by the U.S. National Institutes of Health dated 2003 discloses that |
Other coating material of solar cell show as below:
Amorphous-Si (a-Si) & Multi-junction
Cadmium Telluride (CdTe)
Copper Indium Gallium DiSelenide (CIGS)
TCO - Cd2SnO4, SnO2/Sb2O3, ZnO/Al2O3, ZnO/Al, ZnO/Ga2O3, Zn/MgO
CdTe - CdTe, CdS, Cd2SnO4, Zn2SnO4
Contact Materials - Ag, Ag alloys, Al, Ni/V, Ni, Ti, Cu
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