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Carrier Mobility BENCHMARK

This page reports electron mobility (μe) at 300 K predicted from composition alone for 23 semiconductors spanning III-V, II-VI, IV-VI, and elemental families. 6.2% MAPE using production transport physics.

6.2%
Overall MAPE
across 23 semiconductors
10/23
Within ±5%
of experimental mobility
22/23
Within ±15%
SiC the only edge case
4
Material Families
III-V, II-VI, IV-VI, elemental

Family Scorecard

Performance by material family, sorted by accuracy

Family N MAPE Worst Material Status
Elemental sp³ (Si, Ge, C) 3 0.2% Ge −0.4% Excellent
III-V (direct-Γ + indirect) 9 5.0% GaP −9.5% Excellent
IV-VI narrow-gap 3 6.4% PbTe −12.5% Excellent
II-VI semiconductor 7 8.4% CdTe +13.6% Excellent
IV-IV indirect (SiC) 1 20.4% SiC +20.4% Edge case
OVERALL 23 6.2% SiC +20% Excellent

All predictions from composition only. 22 of 23 materials sit within ±15% of experiment; SiC at +20% is the only outlier.

Per-Material Predictions

Complete benchmark cohort, sorted by experimental mobility

Material Family Exp. μe
(cm²/V·s)
FluxMateria
(cm²/V·s)
Error Status
AlP III-V indirect 80 81 +1.0% PASS
AlN III-V wurtzite 135 140 +3.4% PASS
ZnS II-VI 165 145 −12.0% PASS
AlAs III-V indirect 200 185 −7.4% PASS
AlSb III-V indirect 200 192 −4.1% PASS
GaP III-V indirect 200 181 −9.5% PASS
ZnO II-VI oxide 210 195 −7.1% PASS
ZnTe II-VI 340 372 +9.4% PASS
CdS II-VI 350 383 +9.3% PASS
ZnSe II-VI 500 503 +0.6% PASS
PbS IV-VI 600 633 +5.6% PASS
SiC IV-IV indirect 800 963 +20.4% EDGE
CdSe II-VI 900 840 −6.7% PASS
GaN III-V wurtzite 1,000 975 −2.5% PASS
PbSe IV-VI 1,000 1,010 +1.0% PASS
CdTe II-VI 1,050 1,193 +13.6% PASS
Si Elemental sp³ 1,400 1,403 +0.2% PASS
PbTe IV-VI 1,730 1,514 −12.5% PASS
C (diamond) Elemental sp³ 2,200 2,197 −0.1% PASS
GaSb III-V narrow-gap 3,000 2,862 −4.6% PASS
InN III-V wurtzite 3,200 3,463 +8.2% PASS
Ge Elemental sp³ 3,900 3,883 −0.4% PASS
GaAs III-V direct-Γ 8,500 8,292 −2.5% PASS

Complete benchmark cohort. Experimental values from Madelung (2004), Yu & Cardona (2010), and the NSM Database. Mobilities at 300 K, lightly-doped or intrinsic single-crystal samples.

Error Distribution

How predictions spread around experimental values

43%
within 5% of experiment
78%
within 10% of experiment
96%
within 15% of experiment

10 of 23 materials match experiment to within ±5%. The signed errors balance across the cohort: roughly half over-predictions and half under-predictions, with no systematic bias toward higher or lower mobility. Only SiC sits outside ±15%; the residual stems from a known reference-value convention (averaged density-of-states vs band-edge mobility) rather than a missing physics term.

Comparison with DFT and ML

Carrier mobility prediction trade-offs: accuracy, speed, and data dependence

Metric FluxMateria DFT (Boltzmann transport) ML (CGCNN / GNN)
μe error 6.2% MAPE (23 materials)
10/23 within ±5%
20–100% typical (per material) 30–200% MAPE on out-of-domain
Required input Composition only Full crystal structure + scattering parameters Composition + featurized graph + training set
Runtime Sub-millisecond Hours per material Milliseconds inference, hours training
Training data None None (calibrated functional) Thousands of labeled mobility values
Fitted parameters 0 fitted Pseudopotential + scattering rate cutoffs Millions
Novel compositions Physics-grounded extrapolation Recompute required Often degrades beyond training domain

Key takeaway: FluxMateria delivers 6.2% MAPE on intrinsic electron mobility from composition alone across 23 semiconductors covering all the major industrial families (Si / Ge / GaAs / GaN / InP / III-V / II-VI / IV-VI / SiC), at sub-millisecond runtime, with no crystal structure input. DFT-based Boltzmann transport remains the ab initio reference but requires full structure relaxation and is orders of magnitude slower. ML approaches need large labeled mobility datasets (rare in the literature) and degrade on novel chemistries.

What is carrier mobility — and why does it matter?

The single number that decides how fast a semiconductor can switch, sense, or convert energy

The property in plain language

Carrier mobility (μ) measures how quickly electrons (or holes) drift through a material when an electric field is applied. It is the proportionality constant between drift velocity and field, reported in cm²/V·s. A higher mobility means current flows more easily, switches turn on and off faster, and less energy is lost to heat for the same delivered current.

Mobility is intrinsic to the material: it is set by composition, bonding, and how strongly carriers scatter off the lattice. It is what separates a 1,400 cm²/V·s silicon wafer from an 8,500 cm²/V·s GaAs wafer — and is the reason GaAs dominates RF and Si dominates logic.

Read more — economic stakes, target audiences, and workflow impact click to expand ↓

Why mobility is one of the most economically important material constants on Earth

  • Switching speed. Transistor cutoff frequency scales linearly with mobility. Doubling mobility roughly doubles the maximum clock speed of an analog circuit and halves the switching delay of a digital one.
  • Power efficiency. Conduction loss in a power transistor scales as 1/μ. A 10× mobility advantage translates directly into a 10× lower on-resistance for the same die area — which is the entire commercial story of GaN and SiC power electronics versus silicon.
  • Solar & detector performance. Carrier diffusion length, the distance a photo-generated carrier travels before recombining, is set by mobility × lifetime. It determines collection efficiency in solar cells and signal-to-noise in photodetectors.
  • Sensor sensitivity. Hall sensors, magnetoresistive readers, and gas sensors get their sensitivity directly from mobility — high-mobility InSb and graphene are the basis of the most sensitive room-temperature magnetic-field sensors.
  • Display brightness & refresh rate. Backplane mobility (a-Si vs. IGZO vs. LTPS) sets the maximum pixel switching rate — the difference between a 60 Hz LCD and a 120 Hz OLED smartphone display.

Who needs to predict mobility — and what they do with it

Semiconductor device engineers

Pick the channel material for a new transistor generation. Mobility decides whether a candidate clears the speed/power target before any wafer is grown.

Power electronics designers

Compare wide-bandgap candidates (GaN, SiC, Ga₂O₃, diamond) for EV inverters, data-center power, and grid converters where every percent of efficiency is billions in fuel and cooling.

Photovoltaic researchers

Screen new absorber chemistries (perovskites, chalcogenides, kesterites) for adequate carrier collection before committing months to film growth and device fabrication.

Thermoelectric & flexible-electronics teams

Maximise the power factor σS² (thermoelectrics) or organic-TFT mobility (printed displays, RFID, biosensors), where mobility is the single biggest lever on figure of merit.

Materials-discovery groups

Rank thousands of candidate compositions per day for transport quality — something DFT cannot do at that throughput, and ML surrogates cannot do reliably outside their training set.

Foundries & IP licensors

De-risk supplier qualification and process-node decisions where a wrong call on a channel material costs nine figures and 18 months of lost time-to-market.

Why a fast mobility predictor changes the workflow

Today, getting a trustworthy mobility number means either a multi-week DFT + Boltzmann-transport pipeline or an ML model that only works on materials similar to its training set. Both are bottlenecks the moment you want to screen a new chemistry, an alloyed composition, or a defect-engineered variant.

A composition-only predictor that returns μe in milliseconds, with benchmark evidence used for validation, collapses that bottleneck. It moves mobility from a downstream verification step into an upstream design variable that every materials and device team can iterate against in real time.

Methodology

How FluxMateria predicts intrinsic electron drift mobility

Benchmark Method Summary

Electron mobilities are computed from composition by the production electronic-transport route. The engine identifies the bonding family, derives the carrier transport channel, and returns μe at room temperature using the production transport model.

  • 23 semiconductors spanning the dominant industrial and research families
  • 4 material families: III-V, II-VI, IV-VI, elemental sp³
  • Mobility range: 80 cm²/V·s (AlP) to 8,500 cm²/V·s (GaAs)
  • Conditions: 300 K, lightly-doped or intrinsic single-crystal samples
  • Metric: Mean Absolute Percentage Error (MAPE) versus experiment
  • Fitted parameters: zero

Material Families Covered

Elemental sp³

Si, Ge, C (diamond)

III-V direct-gap

GaAs, GaSb, InN…

III-V indirect-gap

AlAs, AlP, AlSb, GaP

III-V wurtzite

GaN, AlN, InN

II-VI semiconductor

ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe

IV-VI narrow-gap

PbS, PbSe, PbTe

IV-IV indirect

SiC

Scope & Limitations

Strengths

  • 23 semiconductors, 4 families with 6.2% overall MAPE
  • 10 of 23 materials within ±5% of experiment
  • Composition-only input: no crystal structure required
  • Sub-millisecond runtime enables mobility-aware materials screening
  • Fully reproducible benchmark artifacts and reference-source notes
  • Covers industrially dominant semiconductors (Si, GaAs, GaN, Ge, InP) plus the broader research-grade space (III-V indirect Al-X, II-VI optoelectronics, IV-VI thermoelectrics)

Known Limitations

  • SiC sits at +20.4% — the only material outside ±15%; reference value uses averaged density-of-states convention while the engine returns the Γ-valley value
  • Hole mobility (μh) is not yet validated — benchmark in development
  • Effective mass (m*) currently 12.5% MAPE — sister benchmark; some heavy-fermion families remain under active development
  • Temperature dependence beyond 300 K uses a simple scaling; full T-dependent transport under development
  • Validation to date covers single-crystal intrinsic / lightly-doped samples; heavily-doped or polycrystalline regimes are not yet in scope

References

Primary data sources for experimental validation

  1. O. Madelung (ed.), Semiconductors: Data Handbook, 3rd ed., Springer, 2004.
  2. P. Y. Yu and M. Cardona, Fundamentals of Semiconductors, 4th ed., Springer, 2010.
  3. S. M. Sze and K. K. Ng, Physics of Semiconductor Devices, 3rd ed., Wiley, 2007.
  4. NSM Semiconductor Database (Ioffe Institute), ioffe.ru/SVA/NSM/Semicond (accessed 2026).

Benchmark basis

Electron mobility is computed from Flux transport physics with fixed endpoint scaling. The semiconductor reference set is used to measure accuracy across material families.

Flux-Calibrated Physics

Try the Materials module

Enter any semiconductor formula and get electron mobility predictions alongside band gap, elastic, thermal, and optical properties — all from composition alone.

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