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qcl:material_database [2017/02/10 17:43] stefan.birner |
qcl:material_database [2021/01/04 15:04] (current) thomas.grange |
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- | ====== Material database ====== | + | ===== Material database ===== |
- | The material database file is called ''Material_Database.xml''. | + | The default material parameters are stored in a database file called ''Material_Database.xml''. |
- | The [[material database description]] is the same as for the nextnano.MSB code. | + | |
- | The default material parameters are taken from I. Vurgaftman, J. R. Meyer, L. R. Ram-Mohan, J. Appl. Phys. 89, 5815 (2001). | + | This default material database can be open in the nextnanomat GUI though: |
+ | |||
+ | File => Open nextnano.NEGF Default Database | ||
+ | |||
+ | If you run nextnano.NEGF via the nextnanomat GUI, you can choose to read in a customized material database as follows: | ||
+ | |||
+ | nextnanomat => Tools => Options => Material database => nextnano.NEGF database file | ||
+ | |||
+ | Note that this material database shares the same structure with the one of the nextnano.MSB code, which documentation can be found here: | ||
+ | [[https://www.nextnano.com/manual/nextnano.MSB/material_database.html|Material Database]] | ||
+ | |||
+ | Most of the default material parameters are taken from I. Vurgaftman, J. R. Meyer, L. R. Ram-Mohan, J. Appl. Phys. 89, 5815 (2001). | ||
+ | |||
+ | Some parameters can be overwritten in the input file, see section on ''<Material_Parameters>'' in the [[qcl:input_file|input file documentation]]. | ||
+ | |||
+ | <code> | ||
+ | <!-- parameter that accounts for remote-band effects in 8-band k.p theory --> | ||
+ | S = 1+2F | ||
+ | </code> | ||
+ | |||
+ | The deformation potential | ||
+ | |||
+ | <code> | ||
+ | <DeformationPotential Unit="eV">-7.2</DeformationPotential> | ||
+ | </code> | ||
+ | |||
+ | corresponds to ''a_c'' of Vurgaftman (i.e. for the conduction band only) in the isotropic approximation. | ||
+ | It is used to calculate the shift of the conduction band edge due to strain. | ||
+ | It is also used to calculate scattering by acoustic phonons (which is a very small effect, almost negligible in typical QCLs and RTDs). | ||
- | //Comment only relevant for previous executables: | ||
- | A few material parameters that are used by the nextnano.QCL software are stored in the executable itself. | ||
- | Some parameters can be overwritten in the input file, see section on <Material_Parameters> in the input file documentation. | ||
- | // |