Cadmium Telluride

APPLICATIONS

CdTe is a useful material for solar cells ( Photovoltaic s). It is cheaper than Silicon , especially in thin-film Solar Cell technology, but not as efficient.
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 Window s and Lenses . In this application it is sometimes referred to by the trademarked name ''Irtran-6''.

PHYSICAL PROPERTIES

Molecular Weight : 240.02

Density : 5850 kg/m³.

Lattice Constant : 0.648 nm at 300K

Young's Modulus : 52 GPa

Poisson Ratio : 0.41

ELECTRONIC PROPERTIES

The direct band gap is 1.56 EV at 300 K.

Electron Effective Mass 0.11 ''m_e''

Hole effective mass 0.4 ''m_e''

Thermal Properties

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 K

Optical Properties

CdTe is transparent from close to its band gap energy out to infrared Wavelength s greater than 20 µm. The Refractive Index is 2.649 at 10µm.

CHEMICAL PROPERTIES

CdTe has very low Solubility in water. It is etched by many acids including Hydrochloric , and Hydrobromic Acid , forming (toxic) Hydrogen Telluride gas.

Cadmium telluride is commercially available as a powder, or as crystals. It can be made into nanocrystals.

TOXICITY

Cadmium telluride is Toxic . It should not be ingested, nor its dust inhaled, and it should not be handled without appropriate gloves. Please refer to materials safety data sheets for details.

SEE ALSO