CADMIUM TELLURIDE Property

Melting point:

1092 °C

Density 

6.2 g/mL at 25 °C (lit.)

vapor pressure 

0Pa at 25℃

refractive index 

2.75

solubility 

insoluble in H2O, dilute acid solutions

form 

crystalline

color 

Black

Specific Gravity

6.2

Water Solubility 

Insoluble in water.

Crystal Structure

Hexagonal, Wurtzite (Zincite) Structure - Space Group P 63mc

Merck 

14,1629

Boiling point:

1130°C

Exposure limits

ACGIH: TWA 0.01 mg/m3; TWA 0.002 mg/m3; TWA 0.1 mg/m3
NIOSH: IDLH 9 mg/m3; IDLH 25 mg/m3; TWA 0.1 mg/m3

CAS DataBase Reference

1306-25-8(CAS DataBase Reference)

EPA Substance Registry System

Cadmium telluride (CdTe) (1306-25-8)

Safety

Hazard Codes 

T,N,Xn

Risk Statements 

45-20/21/22-50/53

Safety Statements 

53-22-61-60

RIDADR 

UN 2570 6.1/PG 3

WGK Germany 

3

RTECS 

EV3330000

TSCA 

Yes

HazardClass 

6.1(b)

PackingGroup 

III

HS Code 

28429090

Toxicity

mouse,LD,oral,> 15gm/kg (15000mg/kg),Gigiena Truda i Professional'nye Zabolevaniya. Labor Hygiene and Occupational Diseases. Vol. 25(2), Pg. 42, 1981.

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H410Very toxic to aquatic life with long lasting effects

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P273Avoid release to the environment.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P301+P312IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell.

CADMIUM TELLURIDE Chemical Properties,Usage,Production

Chemical Properties

Brownish-black, cubic crystals.Oxidizes on prolonged expo- sure to moist air. Insoluble in water and mineral acids except nitric, in which it is soluble with decomposition.

Physical properties

Ladd investigated the temperature dependence of transmittance in the infrared region. As a result, transmittance in wavelength longer than 22 mm decreases as the temperature increases.
In the transmission spectra, weak absorption bands are observed in addition to the main absorption in λ: 60–70 mm.
The reflectance peaks in the infrared region are at 67 mm (300 K) and 65 mm (90 K)

Uses

Cadmium telluride finds applications as the semiconductor material in photovoltaics and infrared optical window. It is used in the production of thin film solar cells. It is doped with chlorine and used as a radiation detector for x-rays, alfa and beta particles. .

Uses

In semiconductor research, in phosphors.

Uses

Cadmium telluride may be used in photovoltaic solar cells as the window layer. CdTe was used in the preparation of an Au/Cu₂Te/CdTe/CdS/TCO/glass heterostructure for solar cell.

Application

Cadmium telluride is used as the substrate of low-pass filters and as the infrared transmitting window with antireflection coating.

Production Methods

A single crystal of cadmium telluride is grown by many methods. In the case of vapor growth, the methods include flowing a carrier gas or condensing CdTe vapor on a low temperature area. In the case of growth from melt, pulling down a quartz ampoule encapsulated with CdTe at the speed of 10 mm/h in the Stockbarger furnace is the easiest method. The temperature difference of 50℃–60℃ between the upper furnace and lower furnace is appropriate. The traveling method performed in the horizontal Stockbarger furnace is another method. Zone refining is done vertically, while encapsulated in the quartz tube. Processing is possible in the same way as Ge and Si. The material made by pressing cadmium telluride powder is called Irtran-6.
Thin films are deposited by vacuum evaporation using a conical basket heater made of Ta or W, or by direct heating in a boat. The substrate temperature is heated at 250℃ for a glass and 20℃–380℃ for a mica.

General Description

CdTe is a photonic material. Crystal structure of CdTe is zinc blende structure. 3CdTe is usually an obvious choice for photovoltaic applications because of its; low cost, direct band gap (1.44eV),3 high absorption coefficient, easily doped with p and n type dopants by several preparation techniques. 2

Hazard

Toxic by inhalation.

Structure and conformation

The space lattice of CdTe (Cadmium telluride) belongs to the cubic system, and the zinc-blend type structure has a lattice constant of a=0.646 nm and the nearest neighbor atomic distance of 0.279 nm. The cleavage plane is (110).