Cadmium telluride properties

J. Brice and P. Capper, eds., Properties of Mercury Cadmium Telluride, Institution of Electrical Engineers (INSPEC), London, 1987. 

The next step is to provide electrical connections 3 between the electrode leads 13 and the contact pads 23. Because the active regions are present adjacent the passivated lower surface during the heat treatments, for example when the adhesive layer 4 is cured, they do not suffer significantly from degradation of the material properties of the mercury cadmium telluride... 

J John Brice and Peter Capper, "Properties of Mercury Cadmium Telluride , 1NSPEC (The Institution of Electrical Engineers), 1987. 

Menezes C., Sanchez-Sinencio F., Helman J. S., Williams, R. and Dresner J. (1977), Photoelectronic properties of cadmium telluride-electrolyte heterojunctions , Appl. Phys. Lett. 31, 16-18. 

In the form of CdS Sei selenium is used as a red pigment in glass and ceramics. Below its melting point, Se is a semiconductor. Tellurium is used as an additive (<0.1%) to low-carbon steels in order to improve the machine qualities of the metal. This accounts for about half of the world s consumption of tellurium. Catalytic applications are also important, and other applications stem from its semiconducting properties, e.g. cadmium telluride has recently been incorporated into solar cells (see Box 14.3). However, uses of Te are limited, partly because Te compounds are readily absorbed by the body and excreted in the breath and perspiration as foul-smelling organic derivatives. 

Phases formed on semiconductor surfaces can change the electrical properties in an uncontrolled, deleterious fashion. Oxide passivation layers on compound semiconductors (e.g., mercury cadmium telluride IR detectors or gallium arsenide solar cells) can be grown to impart protection to the surfaces and to stabilize electrical properties by preventing uncontrolled reactions. 

Nasar A, Shamsuddin M (1990) Thermodynamic properties of cadmium telluride. High Temp... 

Guillermet AF, Frisk K (1994) Thermochemical assessment and systematics of bonding strengths in solid and liquid MeN 3d transition-metal nitrides. J Alloys Comp 203 77-89 Shamsuddin M, Nasar A (1988/1989) Thermodynamic properties of cadmium telluride. High Temp Sci 28 245-254... 

Nanomaterials in the form of a colloidal solution or quantum dots are attributed to have a tremendous impact in analytical chemistry for their unique physical and chemical properties (Alivisatos 2004 Katz and Willner 2004). A different methodology has been adopted to analyse vitamin Bi spectro-fluorimetrically by using cadmium selenide quantum dots (CdSe QDs), cadmium telluride (CdTe) nanorods, and silica and gold nanoparticles. A fluorescence resonance Rayleigh scattering (RRS) method was applied for determining vitamin Bi at sub-nanomolar level (Liu et al. 2006). In this technique, vitamin Bi was mixed with acidic buffer and prepared gold nanoparticles. After incubation, the solution mixture was excited in synchronous mode to obtain RRS spectra. The RRS spectral intensity correlated with the concentration of vitamin Bi. 

DLC coatings also have an opto-protective function, infrared window materials such as germanium, magnesium fluoride, cadmium telluride, zinc sulfide, and zinc selenide are rel h/ely soft and easily damaged and eroded by wind, rain, or particle impact. They have also poor resistance to corrosive environments. DLC coatings offer good protection with adequate optical properties. However, their narrow IR bandpass may limit the range of applications. 

A lead sulfide photoconductor is the most widely used transducer for the near-1R region of the spectrum from 10,000 to 333 cm(I to 3 pm). It can be operated at room temperature. For mid- and far-lR radiation, MCT photoconductor transducers are used. They must be cooled with liquid nitrogen (77 K) to minimize thermal noise. The long-wavelength cutoff, and many of the other properties of these transducers, depend on the ratio of the mercury telluride to cadmium telluride. which can be varied continuously. 

The other potential semiconductor detector materials have a larger band gap than germanium and consequently would have the advantage of room temperature operation assuming that their other properties were satisfactory. Of these, only cadmium telluride, cadmium zinc telluride (CZT) and mercuric iodide have found their way into... 

Kanoun, M.B., W. Sekkal, H.Aourag, and G. Merad 2000, Molecular-dynamics study of the structural, elastic and thermodynamic properties of cadmium telluride. Phys. Lett. A, 272(1-2) pp. 113-118. 

Capper and Garland 2011) Mercury Cadmium Telluride Growth, Properties and Applications by P. Capper and J. Garland, eds., John Wiley Sons., Cites an expression for Eg x, T) by Hansen et al. [4]. 

Neumann-SpaUart M, Tamizhmani G, Boutry-ForveiUe A, Levy-Clement C (1989) Physical properties of electrochemicaUy deposited cadmium mercury telluride films. Thin Solid Eilms 169 315-322... 

Neumann-Spallart M., Tamizhami G. and Levy-C16ment C. (1990), Photoelectro-chemical properties of semiconducting cadmium mercury telluride thin films with bandgap between 1.47 and 1.08 eV , J. Electrochem. Soc. 137, 3434-3437. 

Antimony is also used as a dopant in -type semiconductors. It is a common additive in dopants for silicon crystals with impurities, to alter the electrical conductivity. Interesting semiconductor properties have been reported for cadmium antimonide [12050-27-0], CdSb, and zinc antimonide [12059-55-9], ZnSb. The latter has good thermoelectric properties. Antimony with a purity as low as 99.9+% is an important alloying ingredient in the bismuth telluride [1504-82-1], Bi Te class of alloys which are used for thermoelectric cooling. 

Table 9 Physical properties of cadmium sulfide, selenide and telluride...

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