BiI3
Bismuth triiodide · Bismuth(III) iodide
Bismuth triiodide is a stable, semiconducting bismuth-based halide used primarily in advanced radiation detection and optoelectronic research.

About Bismuth triiodide
Bismuth triiodide is a semiconducting inorganic compound that exists as a thermodynamically stable phase on the convex hull. Its layered crystal structure and electronic properties make it a subject of significant interest for materials scientists exploring heavy-metal halides.
This material is primarily utilized in the development of high-performance radiation detectors and various optoelectronic devices. Its ability to effectively interact with high-energy photons positions it as a specialized candidate for advanced sensing technologies.
Key Properties
Cross-validated computational properties for Bismuth triiodide, aggregated across 3 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.
Reported Structures
Lowest-energy structures reported for BiI3, 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. |
|---|---|---|---|---|---|
| R-3 (No. 148) | trigonal | 2.53 | 0.0000 | -2.882 | 5.32 |
| P21/c (No. 14) | monoclinic | 2.81 | 0.0017 | -2.880 | 5.24 |
| P-31m (No. 162) | trigonal | 2.49 | 0.0026 | -2.879 | 5.32 |
| P21/c (No. 14) | monoclinic | 2.30 | 0.0202 | -2.862 | 4.41 |
| Pnma (No. 62) | orthorhombic | 2.79 | 0.0342 | -2.848 | 5.01 |
| P21/m (No. 11) | monoclinic | 2.23 | 0.0864 | -2.796 | 4.88 |
| Fm-3m (No. 225) | cubic | 0.00 | 0.5994 | -2.282 | 7.28 |
| Cm (No. 8) | — | — | — | — | — |
| C2/m (No. 12) | Monoclinic | — | — | — | 5.81 |
| R-3 (No. 148) | — | — | — | — | — |
| P21/m (No. 11) | Monoclinic | — | — | — | 4.88 |
| P-31m (No. 162) | Trigonal | — | — | — | 4.78 |
Applications
Where Bismuth triiodide is used.
Frequently Asked Questions
Common questions about Bismuth triiodide, answered from cross-validated data.
What is BiI3?
Bismuth triiodide is a stable, semiconducting bismuth-based halide used primarily in advanced radiation detection and optoelectronic research.
What is BiI3 used for?
What is the band gap of BiI3?
Is BiI3 a metal, semiconductor, or insulator?
Is BiI3 thermodynamically stable?
What is the crystal structure of BiI3?
What is the density of BiI3?
How many polymorphs of BiI3 are known?
What elements does BiI3 contain?
Where does the data for BiI3 come from?
How It Compares
As a prominent heavy-metal halide, bismuth triiodide serves as a benchmark for the class, distinguished by its high atomic number components and stable structural configuration which facilitate efficient charge transport in semiconductor applications.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).
- mpaloe — Data from mpaloe.
Analyze BiI3 in the Lattice Graph platform
Polymorph comparison, confidence scoring, supply-chain risk, and patent monitoring — across 53 integrated data sources.
Explore the Platform →