AlN
Aluminum nitride · AlN
Aluminum nitride is a stable, wide-band-gap semiconductor widely used for its exceptional thermal conductivity and electrical insulation properties.
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.
Key Properties
Cross-validated computational properties for Aluminum nitride, aggregated across 5 databases.
Band GapEnergy needed to move an electron from the valence band to the conduction band. Lower or zero values tend to behave more metallic; larger gaps are more insulating or semiconducting.
Energy Above HullThermodynamic distance from the most stable set of competing phases. 0 eV/atom is on the convex hull; small positive values may still be experimentally accessible.
StabilityA plain-language summary of the best reported energy-above-hull result. It reflects whether the lowest-energy structure is on, near, or far from the stability hull.
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
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 ScoreA normalized confidence score summarizing how closely independent DFT databases agree. Higher scores mean tighter cross-source agreement.
Hull SpreadDifference between the highest and lowest energy-above-hull values reported by comparable sources. Smaller spread means less thermodynamic disagreement.
Sources ComparedNumber and names of computational sources with comparable entries for this formula.
Space Group ConsensusWhether independent sources predict the same crystal symmetry for the lowest-energy structure.
Reported Structures
Lowest-energy structures reported for AlN, ranked by energy above hull.
| Space GroupSymmetry classification of the crystal arrangement. The number is the international space-group index. | Crystal SystemBroad lattice family, such as cubic, tetragonal, monoclinic, or triclinic, derived from unit-cell symmetry. | Band Gap (eV)Electronic gap calculated for this specific reported structure, measured in electronvolts. | E above hull (eV/atom)Thermodynamic distance from the convex hull for this structure, normalized per atom. Lower is generally more stable. | E/atom (eV)Computed total energy normalized per atom. Use energy above hull, not this value alone, when comparing stability. | Density (g/cm³)Mass per relaxed crystal volume, reported in grams per cubic centimeter. |
|---|---|---|---|---|---|
| P63mc (No. 186) | hexagonal | 4.47 | 0.0000 | -1.649 | — |
| P63mc (No. 186) | hexagonal | 4.05 | 0.0000 | -9.610 | 3.20 |
| — | — | 4.45 | 0.0007 | -1.510 | — |
| F-43m (No. 216) | cubic | 3.54 | 0.0204 | -1.629 | — |
| F-43m (No. 216) | cubic | 3.30 | 0.0207 | -9.589 | 3.27 |
| — | — | 3.46 | 0.0214 | -1.489 | — |
| — | — | 3.58 | 0.0224 | -1.488 | — |
| P63/mmc (No. 194) | hexagonal | 3.27 | 0.1153 | -9.495 | 3.42 |
| — | — | 3.56 | 0.1164 | -1.394 | — |
| — | — | 3.53 | 0.1170 | -1.394 | — |
| P63/mmc (No. 194) | hexagonal | 3.69 | 0.1269 | -1.523 | — |
| — | — | 4.64 | 0.1717 | -1.339 | — |
Synthesis Routes
Literature-extracted synthesis procedures targeting AlN.
Applications
Where Aluminum nitride is used.
Patent Landscape
31 patents reference AlN or close compositional variants.
| Patent | Title | Assignee | Granted |
|---|---|---|---|
| 4008111 | AlN masking for selective etching of sapphire | — | — |
| 7532481 | Al/AlN joint material, base plate for power module, power module, and manufacturing method of Al/AlN joint mat | — | — |
| 5370907 | Forming a metallized layer on an AlN substrate by applying and heating a paste of a metal composed of W and Mo | — | — |
| 5061663 | AlN and AlN-containing composites | — | — |
| 12208595 | AlN joined body | — | — |
| 4687657 | Fabrication of SiC - AlN alloys | — | — |
| 5272239 | Silicon-filled aluminum polymer precursors to SiC-AlN ceramics | — | — |
| 11014855 | Transparent AlN sintered body and method for producing the same | — | — |
| 9869422 | Method for preparing bulk C—AlN composite aerogel with high strength and high temperature resistance | — | — |
| 4591537 | Combination of AlN-Y.sub.2 O.sub.3 heat conductive ceramic substrate and electronic component | — | — |
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.
What is AlN used for?
What is the band gap of AlN?
Is AlN a metal, semiconductor, or insulator?
Is AlN thermodynamically stable?
What is the crystal structure of AlN?
How many polymorphs of AlN are known?
How is AlN synthesized?
What elements does AlN contain?
Where does the data for AlN come from?
Related Research
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.
Related Compounds
Other III-V Semiconductors in the database.
Data sources & attribution
- jarvis — Data from JARVIS (jarvis.nist.gov), NIST. Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020). (LicenseRef-US-Gov-PD)
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
- oqmd — Data from the OQMD (oqmd.org). Cite: Saal et al., JOM 65, 1501 (2013); Kirklin et al., npj Comp. Mater. 1, 15010 (2015). (CC-BY-4.0)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
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