Al3P
Al3P is a metallic, thermodynamically unstable aluminum-phosphorus compound that deviates from the typical semiconducting behavior of its III-V family members.
About Al3P
Al3P represents an unconventional stoichiometry within the III-V semiconductor family. Unlike its more common counterparts, this phase exhibits metallic electronic character rather than the typical semiconducting behavior associated with the group. Its existence as a metastable or unstable phase makes it a subject of significant interest for researchers studying phase stability and structural diversity in binary systems. Despite being thermodynamically unfavored, it has been documented across multiple structural databases, highlighting its role in the broader landscape of aluminum-phosphorus chemistry. This compound serves as a critical data point for understanding the limits of structural formation in III-V materials, providing insight into how composition influences electronic properties. While it lacks the wide-gap utility of its cousins, its unique metallic nature invites further investigation into its potential in specialized thin-film or high-pressure synthesis studies.
Key Properties
Cross-validated computational properties for Al3P, 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 Al3P. 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 Al3P, 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. |
|---|---|---|---|---|---|
| Cm (No. 8) | monoclinic | 0.26 | 0.3120 | -0.064 | — |
| — | — | 0.00 | 0.4243 | 0.056 | — |
| P63/mmc (No. 194) | hexagonal | 0.00 | 0.4351 | -7.233 | 2.86 |
| — | — | 0.00 | 0.4356 | 0.067 | — |
| — | — | 0.00 | 0.4364 | 0.068 | — |
| Pm-3m (No. 221) | cubic | 0.00 | 0.4981 | 0.122 | — |
| — | — | 0.00 | 0.5148 | 0.146 | — |
| C2 (No. 5) | monoclinic | — | — | — | 1.83 |
| P1 (No. 1) | triclinic | — | — | — | 2.43 |
| P1 (No. 1) | triclinic | — | — | — | 1.54 |
| P1 (No. 1) | triclinic | — | — | — | 1.69 |
| P1 (No. 1) | triclinic | — | — | — | 1.84 |
Applications
Where Al3P is used.
Frequently Asked Questions
Common questions about Al3P, answered from cross-validated data.
What is Al3P?
Al3P is a metallic, thermodynamically unstable aluminum-phosphorus compound that deviates from the typical semiconducting behavior of its III-V family members.
What is Al3P used for?
What is the band gap of Al3P?
Is Al3P a metal, semiconductor, or insulator?
Is Al3P thermodynamically stable?
What is the crystal structure of Al3P?
What is the density of Al3P?
How many polymorphs of Al3P are known?
What elements does Al3P contain?
Where does the data for Al3P come from?
How It Compares
Within the iii-v semiconductors class.
In contrast to standard III-V semiconductors like AlP or AlN, which are well-known for their wide-gap insulating or semiconducting properties, Al3P deviates significantly by exhibiting metallic behavior. While siblings such as AlAs and GaP are stable, well-behaved materials used extensively in optoelectronics, Al3P remains a structurally complex outlier that sits above the thermodynamic hull, reflecting the distinct structural preferences of this specific aluminum-rich stoichiometry.
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)
- 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)
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
- omat24 — Data from Meta Open Materials 2024 (OMat24), Meta FAIR. Cite: Barroso-Luque et al., arXiv:2410.12771 (2024). (CC-BY-4.0)
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