Trap Energy Level Calculator

Calculator inputs

Material or device label

Optional label for reports and exports.

Calculation method

Choose the available parameter set.

Trap type

This changes the band-edge reference.

Temperature

K

Emission rate

s^-1

Band gap

eV

Optional. Used to estimate position from the opposite band edge.

Attempt-to-escape frequency ν

s^-1

Capture cross section σ

cm²

Thermal velocity v_th

cm/s

Effective density of states N

cm^-3

Temperature uncertainty

±K

Emission rate uncertainty

%

Prefactor uncertainty

%

Chart minimum temperature

K

Chart maximum temperature

K

Example data table

Material	Trap type	Method	Temperature (K)	Emission rate (s^-1)	Prefactor input	Estimated depth (eV)
Silicon	Electron	Attempt frequency	300	1.20e3	ν = 1.00e13 s^-1	0.590
GaAs	Hole	Capture cross section	320	8.50e2	σ = 1.00e-15, v = 1.00e7, N = 1.00e19	0.512
SiC	Electron	Attempt frequency	420	5.00e4	ν = 5.00e12 s^-1	0.667

These rows are sample engineering estimates to show expected inputs and output style.

Formula used

1) Attempt-to-escape frequency method

General form: E = kT ln(ν / e)

Electron trap: E_C − E_T = kT ln(ν / e_n)

Hole trap: E_T − E_V = kT ln(ν / e_p)

2) Capture cross section method

Prefactor: A = σ · v_th · N

Trap depth: E = kT ln(A / e)

The calculator uses the selected trap type to choose the nearest band-edge expression.

3) Arrhenius relation

ln(e) = ln(A) − E / (kT)

For a plot of ln(e) versus 1/T, the slope equals −E/k and the intercept equals ln(A).

Where:

E = trap depth in eV
k = Boltzmann constant in eV/K
T = absolute temperature in K
ν = attempt-to-escape frequency in s^-1
e = measured emission rate in s^-1
σ = capture cross section in cm²
v_th = thermal velocity in cm/s
N = effective density of states in cm^-3

How to use this calculator

Enter a material or device label for reporting.
Select the calculation method that matches your measurement data.
Choose whether the defect behaves as an electron trap or a hole trap.
Provide temperature and measured emission rate.
Enter either attempt frequency or the capture cross section parameter set.
Optionally add band gap and uncertainty values for deeper analysis.
Press the calculate button.
Review the result block above the form, then export CSV or PDF if needed.

8 FAQs

1) What does trap energy level mean?

It describes how far a defect state sits from a nearby band edge. Larger values usually indicate deeper traps that release carriers more slowly and affect switching, leakage, lifetime, or recombination behavior.

2) Which equation does this calculator use?

It uses the thermal emission relation E = kT ln(A/e). The prefactor A comes from either an attempt frequency or the product of capture cross section, thermal velocity, and effective density of states.

3) When should I use attempt frequency mode?

Use it when a reliable attempt-to-escape frequency is known from literature, fitting, or prior measurements. It is fast and convenient when detailed capture cross section data is unavailable.

4) When is capture cross section mode better?

Use it when you have defect-specific transport parameters. This mode is often more physically descriptive because it builds the emission prefactor from cross section, carrier velocity, and effective density of states.

5) Why can the result become invalid or negative?

A physical positive depth requires the prefactor to exceed the emission rate. If not, the logarithm becomes zero or negative, which usually means the input set is inconsistent.

6) What does a deep trap indicate?

A deep trap usually sits farther from the nearest band edge. Such states may hold carriers longer, influence transient response, and contribute to reliability or recombination issues under bias and temperature stress.

7) Can I compare electron and hole traps here?

Yes. The tool switches the reported expression automatically. Electron traps are referenced to the conduction band, while hole traps are referenced to the valence band.

8) Is this enough for final device qualification?

No. This is an engineering estimation tool. Final qualification should also include measurement uncertainty review, extraction method details, device geometry effects, and comparison with experimental characterization data.