Indium Antimonide (InSb) Semiconductors

Topics Covered

Chemical Properties
Electrical Properties
Thermal, Mechanical and Optical Properties
Safety Information


Indium antimonide (InSb) is a crystalline semiconductor made of antimony and indium. It belongs to the III-V group and is a narrow gap semiconductor material. Detectors made of indium antimonide are sensitive and lie between a wavelength of 1 and 5 µm. Indium antimonide was commonly used in mechanically scanned single detector thermal imaging systems.


Indium antimonide finds applications in:

  • As a terahertz radiation source as it is a strong photo-Dember emitter
  • It finds use in infrared detectors, including FLIR systems, thermal imaging cameras, infrared astronomy and in infrared homing missile guidance systems
  • In thermal image detectors using photo-electromagnetic detectors or photodiodes
  • In magnetic field sensors using the Hall effect or magneto-resistance
  • In fast transistors especially due to the high carrier mobility of InSb

Chemical Properties

The chemical properties of indium antimonide are provided in the table below:

Chemical Properties
Chemical Formula InSb
Molecular Weight 236.58 g/mol
CAS No. 1312-41-0
IUPAC Name Indium antimonide
Group III-V
Band Gap 0.17 eV
Band Gap Type Indirect
Crystal Structure Zinc Blende
Symmetry Group Td2-F43m
Lattice Constant 6.479 Angstroms

Electrical Properties

The electrical properties of indium antimonide are provided in the table below:

Electrical Properties
Intrinsic Carrier Concentration 2x1016cm-3
Electron Mobility ≤7.7x104cm2 V-1 s-1
Hole Mobility ≤850 cm2 V-1 s-1
Electron Diffusion Coefficient ≤2x103 cm2 s-1
Hole Diffusion Coefficient ≤22 cm2 s-1
Electrical resistivity 4x10-13Ωcm

Thermal, Mechanical and Optical Properties

The thermal, mechanical and optical properties of indium antimonide are provided in the tables below:

Mechanical Properties
Melting Point 527 °C
Density 5.775 g cm-3
Bulk Modulus 4.7•1011 dyn cm-2
Thermal Properties
Thermal Conductivity 0.18 W cm-1 °C-1
Thermal Diffusivity 0.16 cm2 s-1
Thermal Expansion Coefficient 5.37x10-6 °C-1
Optical Properties
Refractive Index (589 nm @ 293 K) 4
Radiative Recombination Coefficient (@ 300 K) 5x10-11 cm3 s-1

Safety Information

Safety Information
GHS Hazard Statements H302-Harmful if swallowed
H332-Harmful if inhaled
H411-Toxic to aquatic life with long lasting effects
Safety Precautions S 61

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