Indium Nitride (InN) Semiconductors

Topics Covered

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


Indium nitride is a small bandgap semiconductor material having potential application in high speed electronics and solar cells.

The bandgap of indium nitride has been set as ~0.7 eV based on temperature. When alloyed with gallium nitride, the ternary system indium gallium nitride has a direct bandgap span from the ultraviolet (3.4 eV) to the infrared (0.65 eV)

At helium temperatures, thin polycrystalline films of indium nitride can be highly conductive and even superconductive.


Presently research is ongoing on developing solar cells using nitride-based semiconductors. An optical match to the solar spectrum is obtained using the alloy indium gallium nitride. A key challenge to be overcome if these solar cells have to become a commercial reality is p-type doping of indium nitride and indium rich indium gallium nitride.

Chemical Properties

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

Chemical Properties
Chemical Formula InN
Molecular Weight 128.83
CAS No. 25617-98-5
IUPAC Name Indium nitride
Group III-V
Band Gap 0.65 eV
Band Gap Type Direct
Crystal Structure Wurtzite (hexagonal)
Symmetry Group C6v4-P63mc
Lattice Constant 3.112 A

Electrical Properties

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

Electrical Properties
Electron Mobility ≤3200 cm2 V-1 s-1
Electron Diffusion Coefficient ≤80 cm2 s-1

Thermal, Mechanical and Optical Properties

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

Mechanical Properties
Melting Point 1100 °C
Density 6.81 g cm-3
Young's Modulus 308 GPa
Bulk Modulus 140 Gpa
Thermal Properties
Thermal Conductivity 0.45 W cm-1 °C-1
Thermal Diffusivity 0.2 cm2 s-1
Thermal Expansion Coefficient 3.8x10-6 °C-1
Specific Heat 0.32 J g-1 °C-1
Optical Properties
Infrared Refractive Index (300 K) 3.12
Radiative Recombination Coefficient (@ 300 K) 2.0x10-10 cm3 s-1

Safety Information

Indium nitride may cause irritation on the skin, the eye and no sensitizing effects are known. Being exposed to indium compounds may cause pain in the joints and bones, tooth decay, nervous and gastrointestinal disorders, heart pain and general debility. Experiments with animals also indicate that indium may cause reduced food and water consumption with weight loss, pulmonary edema, pneumonia, blood, liver and kidney damage, leg paralysis and damage to the brain, heart, adrenals and spleen. The acute and chronic toxicity of this substance is not fully known.

There is no classification data on carcinogenic properties of this material is available from the EPA, IARC, NTP, OSHA or ACGIH.

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