SiGe
SiGe has a DFT band gap of 0.40–0.99 eV across 55 reported structures in 14 space groups; its reference structure is cubic (Fd-3m (No. 227)). Cross-validated across 3 computational databases.
At a glance
Key Properties
Cross-validated computational properties for SiGe, 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.
0.40–0.99 eV
Range across DFT structures · ground state: narrow gap
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.
0.023 eV/atom
Best (lowest) across sources
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.
Near Hull
3 DFT sources
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
55
3 databases, 14 space groups
Validation
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of SiGe. 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.
0.97 / 1.00
Trust tier: high
Hull SpreadDifference between the highest and lowest energy-above-hull values reported by comparable sources. Smaller spread means less thermodynamic disagreement.
0.009 eV
EAH spread across sources
Sources ComparedNumber and names of computational sources with comparable entries for this formula.
3
jarvis, materials_project, oqmd
Space Group ConsensusWhether independent sources predict the same crystal symmetry for the lowest-energy structure.
All match
Crystallography
Reported Structures
Lowest-energy structures reported for SiGe, 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. |
|---|---|---|---|---|---|
| F-43m (No. 216) | cubic | 0.61 | 0.0162 | -11.307 | 3.93 |
| P21 (No. 4) | monoclinic | 0.51 | 0.0175 | -11.305 | 3.81 |
| F-43m (No. 216) | cubic | 0.69 | 0.0228 | 0.010 | — |
| — | — | 0.76 | 0.0249 | 0.025 | — |
| P63mc (No. 186) | hexagonal | 0.41 | 0.0308 | -11.292 | 3.93 |
| — | — | 0.99 | 0.0558 | 0.056 | — |
| P63mc (No. 186) | hexagonal | 0.40 | 0.0578 | 0.045 | — |
| — | — | 0.88 | 0.0580 | 0.058 | — |
| — | — | 0.00 | 0.3473 | 0.347 | — |
| — | — | 0.00 | 0.3521 | 0.352 | — |
| — | — | 0.00 | 0.3671 | 0.367 | — |
| — | — | 0.00 | 0.4416 | 0.442 | — |
Synthesis
Synthesis Routes
Literature-extracted synthesis procedures targeting SiGe.
Solid State
Procedure available · ceder_solid_state
Intellectual Property
Patent Landscape
11 patents reference SiGe or close compositional variants.
| Patent | Title | Assignee | Granted |
|---|---|---|---|
| 10727073 | Atomic layer etching 3D structures: Si and SiGe and Ge smoothness on horizontal and vertical surfaces | — | — |
| 12252780 | Growth method of highly twinned SiGe alloy on the basal plane of trigonal substrate under electron beam irradi | — | — |
| 7176111 | Method for depositing polycrystalline SiGe suitable for micromachining and devices obtained thereof | — | — |
| 8961810 | SiGe matrix nanocomposite materials with an improved thermoelectric figure of merit | — | — |
| 9018065 | Horizontal epitaxy furnace for channel SiGe formation | — | — |
| 10125415 | Structure for relaxed SiGe buffers including method and apparatus for forming | — | — |
| 9484199 | PECVD microcrystalline silicon germanium (SiGe) | — | — |
| 9752224 | Structure for relaxed SiGe buffers including method and apparatus for forming | — | — |
| 6995076 | Relaxed SiGe films by surfactant mediation | — | — |
| 10837115 | Pre-treatment composition before etching SiGe and method of fabricating semiconductor device using the same | — | — |
Reference
Frequently Asked Questions
Common questions about SiGe, answered from cross-validated data.
What is the band gap of SiGe?
SiGe has a DFT-computed band gap of 0.40–0.99 eV across 55 reported structures. Standard DFT underestimates band gaps, so the measured gap is typically larger.
More questions
Is SiGe a metal, semiconductor, or insulator?
DFT predicts a band gap of up to 0.99 eV (a semiconductor). Measured gaps are typically larger.
Is SiGe thermodynamically stable?
SiGe has a lowest energy above hull of 0.023 eV/atom (near hull).
What is the crystal structure of SiGe?
The reference structure of SiGe is cubic symmetry, space group Fd-3m (No. 227).
What is the density of SiGe?
The computed density of the ground-state structure of SiGe is 3.94 g/cm³.
How many polymorphs of SiGe are known?
55 structures of SiGe are reported across 3 databases, spanning 14 distinct space groups.
How is SiGe synthesized?
Literature-reported routes for SiGe include solid state.
What elements does SiGe contain?
SiGe contains Ge and Si (2 elements).
Where does the data for SiGe come from?
SiGe data is cross-referenced from materials_project, jarvis, oqmd, mpaloe, cod.
Explore
Related Compounds
Other Silicon Anode Materials in the database.
Data sources & attribution
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
- 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)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
- cod — Data from the Crystallography Open Database (crystallography.net/cod/). Cite: Grazulis et al., J. Appl. Cryst. 42, 726 (2009). (CC0-1.0)
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