Aluminum Arsenide (AlAs) Semiconductors

Topics Covered

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


Aluminum arsenide is a semiconductor material that has almost the same lattice constant as that of gallium arsenide. It can form a superlattice with gallium arsenide which results in its semiconductive properties.

Aluminum arsenide readily reacts with acid, acid fumes and moisture. Decomposition of aluminum arsenide will produce hazardous arsenic gas and arsenic fumes.


Aluminum arsenide finds applications in the following areas:

  • Optoelectronic devices
  • Solar cells
  • Quantum well devices
  • High-electron-mobility transistors.

Chemical Properties

The chemical properties of aluminum arsenide are provided in the table below:

Chemical Properties
Chemical Formula AlAs
Molecular Weight 101.9031
CAS No. 22831-42-1
Group Aluminum – 13
Arsenide - 15
Crystal Structure Cubic
Lattice Constant 5.6622 Å

Electrical Properties

The electrical properties of aluminum arsenide are provided in the table below:

Electrical Properties
Dielectric Constant 10.9
Band Gap 2.16 eV
Electron Mobility 1200 cm2/Vs
Hole Mobility 420 cm2/Vs

Thermal, Mechanical and Optical Properties

The thermal, mechanical and optical properties of aluminum arsenide are provided in the tables below:

Thermal Properties
Heat of Formation 627 kJ/mol
Thermal Expansion Coefficient 3.50 µm/m°C
Thermal Conductivity 84 W/mK
Debye Temperature 144°C
Mechanical Properties
Density 3.81 g/cm3
Melting Point 1740°C
Knoop Microhardness 5000
Optical Properties
Refractive Index 3.16
Chromatic Dispersion -1.277 µm-1

Safety Information

Safety Information
GHS Hazard Statements H301 - Toxic if swallowed
H331 - Toxic if inhaled
H410 - Very toxic to aquatic life with long lasting effects.
Safety Precautions P261 - Avoid breathing dust/ fume/ gas/ mist/ vapours/ spray
P273 - Avoid release to the environment
P301 + P310 - If swallowed, immediately call a poison center or doctor/physician
P311 - Call a poison center or doctor/ physician
P501 - Dispose of contents/ container to an approved waste disposal.


  1. Eph Branch Eph Branch India says:

    It has Zinc Blende structure.

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