5.1 Introductory remarks

All parameters can be set in the \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} simulation\_ setup.txt}}\) file and layer files or similar files with different names, see section 3.1. We have tried to break up the parameters into coherent blocks: general, layers, Optics, mobilities etc and split them between two types of files. One which contains the more general parameters that define the device (\(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} simulation\_ setup.txt}}\)), of which there can only be one, but this is specific for either \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} SimSS}}\) or \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} ZimT}}\). The other type of file contains the parameters that define a layer, where each layer must have it’s own parameter file, but they are shared among \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} SimSS}}\) and \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} ZimT}}\). The order of the parameters cannot be changed as \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} SimSS}}\) and \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} ZimT}}\) simply rely on the order of the input parameters to know which value is what. Comments may be added after an asterisk.

Another way of setting individual parameters (except for the number of layers) is to specify them in the command line. This is incredibly useful if you want to run many simulations, for example on a cluster. In case of a general parameter this would be like:

./simss -T 300

This will run \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} SimSS}}\) with a temperature (\(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} T}}\)) of 300 K and overrides the value that is specified in the file \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} simulation\_ setup.txt}}\). When changing a parameter for a specific layer, the parameter name must be preceded by the layer index parameter, see \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} l1}}\), separated by a dot, for example: ¹

./simss -l1.L 200E-9

This will run \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} SimSS}}\) with a thickness (\(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} L}}\)) of 200 nm for the first layer and overrides the value that is specified in the parameter file for the first layer.

There one option that can be used but that are not in the parameter file:

./simss -h

will make \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} SimSS}}\) show a short help message and exit (even if more parameters are specified).

A note on the units: \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} SimSS}}\) and \(\mathtt{\require{color}{\color[rgb]{0.000000000000000,0.500000000000000,0.500000000000000} ZimT}}\) use SI units only, except for eV instead of J for work functions and other energies. So no cm\(^2\) or mA, but only m\(^2\) or A.