3.1 Device and simulations parameters

The most important input files are the ones that specify all properties of the device and layers, where input and output files can be found, etc. By default, the \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} SimSS}}\) and \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} ZimT}}\) look for a file called \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} simulation\_ setup.txt}}\) for the device and simulation parameters. The parameters that define each layer are in separate files as specified in \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} simulation\_ setup.txt}}\). All input and output files are simple text files and are human-readable. For input files and the \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} logFile}}\), we use the extension \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} .txt}}\), while for output files that are used to store or plot data, we prefer the \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} .dat}}\) extension.

The \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} simulation\_ setup.txt}}\) file starts like this: ¹

** SimSS Simulation Setup:
** version: 5.36

**General***********************************************
T = 295                   * K, absolute temperature

**Layers************************************************
l1 = L1_parameters.txt    * parameter file for layer 1, mandatory
l2 = L2_parameters.txt    * parameter file for layer 2
...

The order of the parameters is fixed and cannot be changed. However, comments may be added by simply inserting an asterisk at the end of a line (like shown above). If the comment is to be left-justified, use two asterisks. Section 5 lists and defines all parameters. For a detailed description of these files and the parameters, refer to chapter 5. An important remark, an interface defined in a layer parameter file always refers to the interface with the current layer and the adjacent layer to the right. This holds for all layers except for the interface between the rightmost layer and the contact, which we do not treat as a relevant interface. The parameters that define the interface are specified in the block Interface-layer-to-right. Each layer file must have such a block, even if it is the last (rightmost) layer in the device stack.

It is also possible to specify a different device parameter file via the command line. This must be the first parameter that is passed and should simply state the name of the file:

./zimt different_par_file.txt

Now \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} ZimT}}\) will look for file \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} different\_ par\_ file.txt}}\). Of course, such a parameter file must have the same structure and parameters as the default one. Again, one can change other general parameters values via the command line like

./zimt different_par_file.txt -T 350

or layer specific parameters like

./zimt different_par_file.txt -l1.L 150E-9