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Knowledge Base

Creates a struct with material parameters for use with mqwgain command.

 

FDTD STACK MODE DGTD CHARGE HEAT FEEM INTERCONNECT

 

Syntax

Description

result = buildmqwmaterial(location, T, matname, x);

Ternary materials.

 

location: string specifying the path to the database file. Alternatively, if empty struct, the default database will be used.

T: temperature.

matname: ternary material name.

x: material composition.

 

result: struct with material properties.

result = buildmqwmaterial(location, 300, matname, x, cbValley);

same as above with the additional parameter cbValley that specifies which conduction band valleys will be included for the interpolation of parameters. Possible values: “Gamma”, “X”, “L”, or “All” (default is “Gamma”; option “All” uses the lowest band gap to select).

result = buildmqwmaterial(location, 300, matname, x, y);

Quaternary material with compositions x and y.

result = buildmqwmaterial(location, 300, matname, x, y, cbValley);

Quaternary material with compositions x and y and the valley mixing specifier.

 

The supported materials are listed in the table below:

 

III-V semiconductors

Ternary alloys

Quaternary Alloys

AlAs

AlxGa1-xAs

InxGa1-xAsyP1-y

GaAs

AlxGa1-xP

 

InAs

AlxIn1-xP

 

AlP

GaAsxP1-x

 

GaP

InxAl1-xAs

 

InP

InAsxP1-x

 

 

InxGa1-xAs

 

 

InxGa1-xP

 

 

When database materials are used, the properties of ternary alloys P(AxB1−xD) are interpolated from the corresponding properties of the base materials (P(AD) and P(BD)) according to the formula

 

\( P\left(A_x B_{1-x}D\right)=xP\left(AD\right)+\left(1-x\right)P\left(BD\right)+x\left(1-x\right)C \),

 

where x is the composition fraction and C is the bowing parameter (quadratic coefficient). Quaternary alloys are composed from the interpolation of ternary alloy constituents [1]:

 

\( P\left(A_xB_{1-x}C_yD_{1-y}\right)=\frac{x\left(1-x\right)\left[\left(1-y\right)P\left(A_xB_{1-x}D\right)+yP\left(A_xB_{1-x}C\right)\right]+y\left(1-y\right)\left[xP\left(AC_yD_{1-y}\right)+\left(1-x\right)P\left(BC_yD_{1-y}\right)\right]}{x\left(1-x\right)+y\left(1-y\right)} \),

 

for composition fractions x and y. For example, a combination of the properties of InxGa1−xP, InxGa1−xAs, InAsyP1−y, and GaAsyP1−y is used to define the properties of InxGa1−xAsyP1−y.

 

result is a struct with the following fields:

 

Coefficient

Units

Description

eg

eV

Band gap

ep

eV

Energy parameter for the optical matrix element

me

1/m0

Electron effective mass

gamma1

 

Luttinger parameter

gamma2

 

Luttinger parameter

gamma3

 

Luttinger parameter

ac

eV

Conduction band deformation potential

av

eV

Valence band deformation potential

b

eV

Valence band deformation potential

c11

N/m2

Elastic stiffness coefficient

c12

N/m2

Elastic stiffness coefficient

lc

m

Lattice constant

vb

eV

Valence band absolute energy (all layers should have common reference)

 

References

[1] Vurgaftman et al., J. Appl. Phys., 89, 5815 (2001)

 

Example

mymat = buildmqwmaterial(“/home/auser/myfolder/my_material_db.json”, 300, “InAlAs”, 0.47);

 

See Also

mqwgain

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