Cadmium Telluride (CdTe)
Cadmium Telluride (CdTe)
APPLICATIONS: Cadmium Telluride can be used for spectroscopy and where deep
IR transmission is required. It is relatively workable and offers transmission to >20µm.
CdTe has some application for solar cells.
µm
0.8
2.5
4.0
7.0
12.5
22.2
27.03
0.85 to 28µm (1)(3)
2.653 @ 10µm (1)
32% @ 10µm
n/a
n/a
5.0 x 10-5 K-1
n/a
Density
Melting Point
Thermal Conductivity
Thermal Expansion
Hardness
Specific Heat Capacity
Dielectric Constant
Youngs Modulus (E)
Shear Modulus (G)
Bulk Modulus (K)
Elastic Coefficients
Apparent Elastic Limit
Poisson Ratio
6.2 g cm-3 (2)
1092 °C
6.2 W.m-1.K-1 at 293 K
5.9x10-6 K-1 at 293 K
Knoop 54 (3)
210 J.kg-1.K-1 at 293 K
11 @ 1MHz
36.52 GPa
n/a
25 GPa
C11=53.51; C12=36.81; C44=19.94
5.9 MPa (3)
0.41
Solubility
Molecular Weight
Class/Structure
Insoluble in water
240.02
Cubic ZnS (110) cleavage
CdTe is rarely used because of its toxicity. The finished optics are not particularly
hazardous but should be handled with care. However, difficulties with processing
cadmium compounds means that very few optical companies will cut and polish the
material. Crystran Ltd does not supply CdTe. This data is provided for reference only.
A form of CdTe was originally utilised as the obsolete Kodak designation of IRTRAN-6
µm
1.0
3.0
5.0
8.0
15.5
24.8
No
2.840
2.695
2.684
2.677
2.6407
2.5801
µm
2.0
3.5
6.0
10.0
20.0
26.32
No
2.713
2.691
2.681
2.653
2.614
2.570
0.8
0.7
50K
0.6
2mm samples
Cadmium Telluride CdTe
0.5
Ttransmission
Transmission Range
Refractive Index
Reflection Loss
Absorption Coefficient
Reststrahlen Peak
dn/dT
dn/dµ = 0
No
2.876
2.702
2.6807
2.679
2.646
2.601
2.564
0.4
300K
50K
0.3
Data from University of Reading
Infrared Multilayer laboratory
0.2
0.1
16
18
20
22
24
26
28
30
32
34
36
38
Wavelength (µm)
CAUTION: Cadmium salts are considered TOXIC and should be handled with care.
(1) Handbook Optical Constants, ed Palik, V1, ISBN 0-12-544420-6
(2) NIST USA data
(3) Hawkins, Sherwood, Djotni: Mid IR Filters for astronomical and remote sensing
instrumentation. Invited Paper SPIE Conference Glasgow 2008
Materials Data from Crystran Ltd . Poole . UK
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