Creates a struct with material parameters for use with mqwgain and mqwindex commands.
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 |
AlxGayIn1-x-yAs |
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 of type AxB1-xCyD1-y (two group III and two group V elements) 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.
Quaternary alloys of type AxByC1-x-yD (three group III elements and one group V element) are composed from the interpolation of ternary alloy constituents [1]:
$$ P\left(A_xB_yC_{1-x-y}D\right)=\frac{xyP\left(A_{1-u}B_uD\right)+y(1-x-y)P\left(B_{1-v}C_{v}D\right)+x(1-x-y)P\left(A_{1-w}C_{w}D\right)}{xy+y(1-x-y)+x(1-x-y)}, $$
for composition fractions x and y and u = (1-x+y)/2, v = (2-x-2y)/2, w = (2-2x-y)/2. For example, a combination of the properties of Al1-uGauAs, Ga1-vInvAs, and Al1-wInwAs, is used to define the properties of AlxGayIn1-x-yAs.
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) |
eps |
|
Relative static permittivity |
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