AlN

Aluminum nitride · AlN

Aluminum nitride is a stable, wide-band-gap semiconductor widely used for its exceptional thermal conductivity and electrical insulation properties.

Crystal structure of AlN (hexagonal, P63mc (No. 186))
Ground-state structure · Materials Project
Overview

About Aluminum nitride

Aluminum nitride is a robust III-V semiconductor characterized by its wide-band-gap electronic structure. As a thermodynamically stable compound, it maintains structural integrity under extreme conditions, making it a critical material for high-performance electronics and heat management systems. Its unique combination of insulating properties and efficient thermal transport distinguishes it from many other semiconductors. The material is extensively documented, with hundreds of reported structural configurations reflecting its versatility in research and industrial applications. It serves as a foundational component in modern power electronics and light-emitting technologies where thermal dissipation is a primary design constraint.

At a glance

Key Properties

Cross-validated computational properties for Aluminum nitride, aggregated across 4 databases.

Band Gap

3.27–4.42 eV
Range across DFT structures

Energy Above Hull

0.000 eV/atom
Best (lowest) across sources

Stability

On hull (stable)
2 DFT sources

Structures

684
4 databases, 53 space groups
Validation

Cross-Source DFT Agreement

How well independent DFT databases agree on the thermodynamics of AlN. Tight agreement means computed properties can be trusted without re-running calculations.

Agreement Score

1.00 / 1.00
Trust tier: medium

Hull Spread

0.000 eV
EAH spread across sources

Sources Compared

2
jarvis, materials_project

Space Group Consensus

All match
Crystallography

Reported Structures

Lowest-energy structures reported for AlN, ranked by energy above hull.

Space GroupCrystal SystemBand Gap (eV)E above hull (eV/atom)E/atom (eV)Density (g/cm³)
P63mc (No. 186)hexagonal4.050.0000-9.6103.20
F-43m (No. 216)cubic3.310.0207-9.5893.27
P63/mmc (No. 194)hexagonal3.270.1153-9.4953.42
Fm-3m (No. 225)cubic4.420.1720-9.4384.04
P1 (No. 1)Triclinic3.62
C2/m (No. 12)Monoclinic3.28
C2/m (No. 12)Monoclinic2.60
C2/m (No. 12)Monoclinic2.73
Pm (No. 6)Monoclinic2.53
Pmm2 (No. 25)Orthorhombic2.76
P1 (No. 1)Triclinic3.03
P-1 (No. 2)Triclinic3.31
Uses

Applications

Where Aluminum nitride is used.

Heat sinksSubstrates for microelectronicsOptoelectronic devicesPiezoelectric sensorsPower electronics
Reference

Frequently Asked Questions

Common questions about Aluminum nitride, answered from cross-validated data.

What is AlN?

Aluminum nitride is a stable, wide-band-gap semiconductor widely used for its exceptional thermal conductivity and electrical insulation properties.

More questions
What is AlN used for?
Aluminum nitride (AlN) is used in heat sinks, substrates for microelectronics, optoelectronic devices, piezoelectric sensors, and power electronics.
What is the band gap of AlN?
Aluminum nitride (AlN) has a DFT-computed band gap of 3.27–4.42 eV across 684 reported structures.
Is AlN a metal, semiconductor, or insulator?
With a wide band gap up to 4.42 eV it is an insulator / wide-band-gap material.
Is AlN thermodynamically stable?
Yes — Aluminum nitride (AlN) sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
What is the crystal structure of AlN?
The lowest-energy reported polymorph of Aluminum nitride (AlN) is hexagonal symmetry, space group P63mc (No. 186).
What is the density of AlN?
The computed density of the ground-state structure of Aluminum nitride (AlN) is 3.20 g/cm³.
How many polymorphs of AlN are known?
684 structures of AlN are reported across 4 databases, spanning 53 distinct space groups.
What elements does AlN contain?
Aluminum nitride (AlN) contains Al and N (2 elements).
Where does the data for AlN come from?
AlN data is cross-referenced from materials_project, mpaloe, cod.
Comparison

How It Compares

Within the iii-v semiconductors class.

Within the family of III-V semiconductors, Aluminum nitride stands out for its superior thermal conductivity compared to siblings like GaN or InN. While many members of this class are primarily valued for their optoelectronic properties, AlN is uniquely positioned as both a semiconductor and an effective dielectric or heat-spreading substrate, offering a distinct balance of electronic and mechanical stability that sets it apart from softer or less thermally conductive counterparts like AlSb or InP.

Explore

Related Compounds

Other III-V Semiconductors in the database.

Data sources & attribution
  • materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
  • mpaloe — Data from mpaloe.
  • cod — Data from the Crystallography Open Database. Cite: Grazulis et al., Nucleic Acids Res. 40, D420 (2012).

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