Zinc telluride
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| Zinc telluride | |
|---|---|
| Image:Zinc telluride.jpg | |
| General | |
| Other names | |
| Molecular formula | ZnTe |
| Molar mass | 192.99 g/mol |
| Appearance | red crystals |
| Crystal structure | cubic |
| CAS number | [1315-11-3] |
| Properties | |
| Density and phase | 6.34 g/cm3, solid |
| Solubility | decomposes in water |
| Melting point | 1238.5°C |
| Boiling point | |
| Band gap | 2.24 eV |
| Lattice constant | 0.61034 nm |
| Hazards | |
| EU classification | not listed |
| NFPA 704 | |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references | |
Zinc telluride (ZnTe) is an intrinsic semiconductor material with band gap of 2.23-2.25 eV. It is usually a p-type semiconductor. Its crystal structure is cubic, of sphalerite.
Contents |
[edit] Properties
Its lattice constant is 0.61034 nm, allowing it to be grown with or on aluminium antimonide, gallium antimonide, indium arsenide, and lead selenide. [1] The CAS number of ZnTe is [1315-11-3] [2]. Its melting point is 1238.5 °C. It has the appearance of grey or brownish-red powder, or ruby-red crystals when refined by sublimation.
The enthalpy is 10980 J.mol−1.
Zinc telluride can be also prepared as hexagonal crystals.
[edit] Applications
[edit] Optics
Zinc telluride can be used as an optical material in infrared optics. However, if optical beam irradiance limits are exceeded, it can burn in presence of oxygen.
[edit] Optoelectronics
Zinc telluride is important for development of various semiconductor devices, including blue LEDs, laser diodes, solar cells, microwave parts, etc.
Solar cells may be made of a thin layer of cadmium telluride grown on thicker layer of cadmium sulfide, which is deposited on a background layer of zinc telluride, forming a PIN structure, where ZnTe is the P-type semiconductor, CdS is the I-type semiconductor, and CdTe is the N-type semiconductor.
Nonlinear optical materials such as zinc telluride or lithium niobate can be used for generation of terahertz radiation. When a crystal of such material is subjected to a high-intensity light pulse of sub-picosecond duration, it emits a pulse of terahertz radiation through a nonlinear optical process. Conversely, subjecting a zinc telluride crystal to terahertz radiation causes it to show optical birefringence and change the polarization of transmitting light, making it useful as a detector. [3] A crystal of zinc telluride can be used for terahertz imaging, when illuminated by a readout laser beam, making the changes caused by exposure to terahertz radiation visible. [4] Gallium phosphide can be used for the same purpose as well. However, the quality of the materials vary wildly from vendor to vendor and even from batch to batch. [5]
For terahertz processing, zinc telluride crystals have to be cooled to near liquid nitrogen temperatures (~80 K).
[edit] Electro-optics
Vanadium doped zinc telluride (ZnTe:V) is a non-linear optical photorefractive material with possible use to protect sensors at visible wavelengths, as an electro-optic power limiter (EOPL). ZnTe:V optical limiters are light and compact, without complicated optics of conventional limiters. ZnTe:V can block a high-intensity jamming beam from a laser dazzler, while still passing the lower-intensity image of the observed scene. [6] It can also be used in holographic interferometry, in reconfigurable optical interconnections, and in laser phase conjugation devices. It offers superior photorefractive performance at wavelengths between 600-1300 nm, in comparison with other III-V and II-VI compound semiconductors. By adding manganese as an additional dopant (ZnTe:V:Mn), its photorefractive yield can be significantly increased. [7]
[edit] See also
[edit] External links
- National Compound Semiconductor Roadmap (Office of Naval research) - Accessed April 2006
