ternary-zb-default
Ternary zinc blende parameters
Parameters for zinc blende type ternary alloys. This parameter set refers to
the binary constituents and their material parameters and specifies the bowing
parameters for interpolation between the binaries.
Please check the Database section for more details:
$ternary-zb-default
Bowing parameters b are defined for
Q[AxB1-xC] = x * Q[AC] + (1-x) * Q[BC] - b
* x * (1-x).
b is defined as b = 4Q(A0.5B0.5C) -
2[ Q[AC] + Q[BC] ].
The advantage of the bowing model is that it requires knowledge of the
relevant quantity only at a composition x=0.5 together with the values for the
binaries.
!---------------------------------------------------------------!
$ternary-zb-default
optional !
ternary-type
character
required ! Al(x)Ga(1-x)As-zb-default,
must be a declared binary material
ternary-name
character
optional !
apply-to-material-numbers
integer_array required !
binary(x)
character
optional ! AlAs-zb-default, must
be a defined binary material
binary(1-x)
character
optional ! GaAs-zb-default, must
be a defined binary material
!
bow-conduction-band-masses
double_array
optional !
bow-conduction-band-nonparabolicities double_array
optional !
bow-conduction-band-energies
double_array
optional !
!
bow-valence-band-masses
double_array
optional !
bow-valence-band-nonparabolicities
double_array
optional !
bow-valence-band-energies
double_array
optional ! average valence band edge energy
!
bow-lattice-constants
double_array
optional !
bow-elastic-constants
double_array
optional !
bow-piezo-electric-constants
double_array
optional !
!
bow-static-dielectric-constants
double_array
optional !
bow-optical-dielectric-constant
double
optional !
!
band-shift
double
optional ! to adjust band
alignments (should be zero in database)
bow-band-shift
double
optional ! to adjust band
alignments, using band shifts specified for binaries
!
bow-abs-deformation-pot-vb
double
optional !
bow-abs-deformation-pots-cbs
double_array
optional ! bow absolute deformation
potentials of conduction band minima
bow-uniax-vb-deformation-pots
double_array
optional ! b,d related
bow-uniax-cb-deformation-pots
double_array
optional !
!
bow-Luttinger-parameters double_array
optional !
bow-6x6kp-parameters
double_array
optional !
bow-8x8kp-parameters
double_array
optional !
!
bow-LO-phonon-energy
double
optional !
!
$end_ternary-zb-default
optional !
!---------------------------------------------------------------!
ternary-type = character
=
Al(x)Ga(1-x)As-zb-default
If the string is a known material-type, the default parameters for this
material type will be read from the database first. By specifying some of the
parameters by the present keyword and specifiers, the defaults will be
overwritten.
If the string is not known to the database, you will be prompted for
all of the material parameters. In this case you have to specify the relevant
specifiers in
$material (material-model,
material-type). If here a known material-type is specified,
however, then not all material parameters are needed as the defaults are taken
unless otherwise specified. See here for an example:
$material
The binary
constituents can still be either known or unknown binary materials.
ternary-name = string
String is a name of your choice.
apply-to-material-numbers = num1 num2 ...
Intended to change only some parameters for some materials which are otherwise
identical.
binary(x) = string
String can be either a known binary or an arbitrary name. In case this binary is
not a known material, you will be prompted for all material parameters. In its
current implementation, there are only a few checks with respect to the number
of data expected for each parameter. Most likely, the program will simply crash
if something is specified which differs from the data structure of a known
material.
binary(1-x) = string
The name of the second binary for the alloy. Limitations and problems as for the
other binary.
bow-conduction-band-masses = double1 double2 ...
Bowing parameters for the effective masses in the conduction band minima. The
ordering corresponds to the ordering of the masses in the binary constituents.
For each set of degenerate minima a triplet of bowing parameters for the three
masses associated to the minimum.
bow-conduction-band-nonparabolicities = double1 double2 ...
Bowing parameters for the nonparabolicity parameters in the conduction band
minima. One nonparabolicity parameter for each set of degenerate minima.
bow-conduction-band-energies = double1 double2 ...
Bowing parameters for conduction band energies. One bowing parameter for each
set of degenerate minima.
bow-valence-band-masses = ...
bow-valence-band-nonparabolicities = ...
bow-valence-band-energies = ...
The valence band energies for heavy, light and split-off holes are calculated by
defining an average valence band energy Ev,av for all three bands and adding the
spin-orbit-splitting energy afterwards. The spin-orbit-splitting energy Deltaso is
defined together with the k.p parameters.
The average valence band energy Ev,av is defined on an absolute
energy scale and must take into accout the valence band offsets which are
averaged over the three holes.
band-shift = double
Can be used to rigidly shift the band energies.
bow-band-shift = double
Bowing parameter to interpolate rigid band shift of binaries.
bow-abs-deformation-pot-vb = double
Bowing parameter for absolute deformation potential of valence band.
bow-abs-deformation-pots-cbs = double1 double2 ...
Bowing parameters for absolute deformation potential of conduction bands.
bow-uniax-vb-deformation-pots = double1 ...
Bowing parameters for uniaxial deformation potentials of valence bands.
bow-uniax-cb-deformation-pots = double1 ...
Bowing parameters for uniaxial deformation potentials of conduction bands.
bow-lattice-constants = double1 double2 double3
Bowing parameters for lattice constants.
bow-elastic-constants = double1 double2 double3
Bowing parameters for elastic constants c11,c12,c44.
bow-piezo-electric-constants = double1 double2 double3
Bowing parameters for piezoelectric constants.
bow-static-dielectric-constants = double1 double2 double3
Bowing parameters for static dielectric constants.
bow-optical-dielectric-constant = double
Bowing for high frequency dielectric constant.
bow-Luttinger-parameters = gamma1
gamma2 gamma3 ! []
kappa q ! []
Note: The Luttinger parameters are only used if the following
$numeric-control flag is set:
Luttinger-parameters = yes
bow-6x6kp-parameters = L M N ! [hbar2/(2m0)]
DeltaSO ! [eV]
Bowing parameters for 6x6 k.p model.
bow-8x8kp-parameters = L' M'=M N'
! [hbar2/(2m0)]
B EP S ! [hbar2/(2m0)]
[eV] []
Bowing parameters for 8x8 k.p model.
Important: There are different definitions of the
L and M parameters available in the literature. (The
gammas are called Luttinger parameters.)
L = ( - gamma1
- 4gamma2 - 1 ) * [hbar2/(2m0)]
M = ( 2gamma2 - gamma1 - 1 ) * [hbar2/(2m0)]
alternative definition: L = ( -
gamma1 - 4gamma2 ) * [hbar2/(2m0)]
M = ( 2gamma2 - gamma1
) * [hbar2/(2m0)]
Note: The S
parameter is also defined in the literature as F
where S = 1 + 2F, e.g. I. Vurgaftman et al., JAP 89,
5815 (2001).
S
has the value 2 * F.
More information
on k.p parameters...
bow-LO-phonon-energy = 0d0
! [eV] low-temperature optical phonon energy
Please check the Database section for more details:
$ternary-zb-default
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