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| Identifiers | |
|---|---|
3D model (JSmol) | |
| ChemSpider |
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| ECHA InfoCard | 100.013.812 |
| EC Number |
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| RTECS number |
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| UNII | |
| UN number | 1549 |
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| Properties | |
| InSb | |
| Molar mass | 236.578 g·mol−1 |
| Appearance | Dark grey, metallic crystals |
| Density | 5.7747 g⋅cm−3[1] |
| Melting point | 524 °C (975 °F; 797 K)[1] |
| Band gap | 0.17 eV |
| Electron mobility | 7.7 mC⋅s⋅g−1 (at 27 °C) |
| Thermal conductivity | 180 mW⋅K−1⋅cm−1 (at 27 °C) |
Refractive index (nD) | 4[2] |
| Structure | |
| Zincblende | |
| T2d-F-43m | |
a = 0.648 nm | |
| Tetrahedral | |
| Thermochemistry[3] | |
| 49.5 J·K−1·mol−1 | |
Std molar entropy(S⦵298) | 86.2 J·K−1·mol−1 |
Std enthalpy of formation(ΔfH⦵298) | −30.5 kJ·mol−1 |
Gibbs free energy(ΔfG⦵) | −25.5 kJ·mol−1 |
| Hazards | |
| GHS labelling: | |
  [4] | |
| Warning | |
| H302,H332,H411 | |
| P273 | |
| Safety data sheet (SDS) | External SDS |
| Related compounds | |
Otheranions | Indium nitride Indium phosphide Indium arsenide |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Indium antimonide (InSb) is a crystallinecompound made from theelementsindium (In) andantimony (Sb). It is a narrow-gapsemiconductor material from theIII-V group used ininfrared detectors, includingthermal imaging cameras,FLIR systems,infrared homingmissile guidance systems, and ininfrared astronomy. Indium antimonide detectors are sensitive to infrared wavelengths between 1 and 5 μm.
Indium antimonide was a very common detector in the old, single-detector mechanically scanned thermal imaging systems. Another application is as aterahertz radiation source as it is a strongphoto-Dember emitter.
The intermetallic compound was first reported by Liu and Peretti in 1951, who gave its homogeneity range, structure type, and lattice constant.[5] Polycrystalline ingots of InSb were prepared byHeinrich Welker in 1952, although they were not very pure by today's semiconductor standards. Welker was interested in systematically studying the semiconducting properties of the III-V compounds. He noted how InSb appeared to have a small direct band gap and a very high electron mobility.[6] InSb crystals have been grown by slow cooling from liquid melt at least since 1954.[7]
In 2018, a research team atDelft University of Technology claimed that indium antimonidenanowires showed potential application in creatingMajorana zero modequasiparticles for use inquantum computing;Microsoft opened a laboratory at the university to further this research, however Delft later retracted the paper.[8][9]
InSb has the appearance of dark-grey silvery metal pieces or powder with vitreous lustre. When subjected to temperatures over 500 °C, it melts and decomposes, liberating antimony andantimony oxide vapors.
Thecrystal structure iszincblende with a 0.648 nmlattice constant.[10]
InSb is a narrow direct band gap semiconductor with an energyband gap of 0.17 eV at 300 K and 0.23 eV at 80 K.[10]
Undoped InSb possesses the largest ambient-temperatureelectron mobility of 78000 cm2/(V⋅s),[11] electrondrift velocity, andballistic length (up to 0.7 μm at 300 K)[10] of any known semiconductor, except forcarbon nanotubes.
Indium antimonidephotodiode detectors arephotovoltaic, generating electric current when subjected to infrared radiation. InSb's internalquantum efficiency is effectively 100% but is a function of the thickness particularly for near bandedge photons.[12] Like all narrow bandgap materials InSb detectors require periodic recalibrations, increasing the complexity of the imaging system. This added complexity is worthwhile where extreme sensitivity is required, e.g. in long-range military thermal imaging systems. InSb detectors also require cooling, as they have to operate at cryogenic temperatures (typically 80 K). Large arrays (up to 2048×2048 pixels) are available.[13]HgCdTe andPtSi are materials with similar use.
A layer of indium antimonide sandwiched between layers of aluminium indium antimonide can act as aquantum well. In such aheterostructure InSb/AlInSb has recently been shown to exhibit a robustquantum Hall effect.[14] This approach is studied in order to construct very fasttransistors.[15]Bipolar transistors operating at frequencies up to 85 GHz were constructed from indium antimonide in the late 1990s;field-effect transistors operating at over 200 GHz have been reported more recently (Intel/QinetiQ).[citation needed] Some models suggest that terahertz frequencies are achievable with this material. Indium antimonide semiconductor devices are also capable of operating with voltages under 0.5 V, reducing their power requirements.[citation needed]
InSb can be grown by solidifying a melt from the liquid state (Czochralski process), orepitaxially byliquid phase epitaxy,hot wall epitaxy ormolecular beam epitaxy. It can also be grown fromorganometallic compounds byMOVPE.[citation needed]
