In this tutorial, we present the NanoTCAD ViDES module and the script to run simulations of Transition Metal Dichalcogenides (TMDs) based transistors. The model is a simple isotropic symmetric 2 bands model (with a double degeneracy), within the effective mass approximation. By default, the module simulate monolayer MoS2 FET, but any metal dichalcogenide can be simulate, setting the electron and hole effective masses, as well as the band-gap.
Download the module_TMD.txt and tutorial_TMD.txt and, as usual, rename as module_TMD.py and tutorial_TMD.py, respectively. Copy the module and the script in the same directory.
Run the script as usual with the command: python tutorial_TMD.py
The script computes the transfer characteristics of a 10 nm long MoS2 transistor with 10 nm long source and drain doped reservoirs. The structure of the script is the same as the one shown in the previous tutorials: PLEASE refer to them for more accurate information.
The only thing different is the TMD class, which as input requires the length of the device and a string, either “n” or “p”, in case you want to simulate nMOS or pMOS, respectively.
You can also simulate different TMD material, just by changing the fields me, mh and Egap, for the electron and hole relative effective mass, and the bandgap rispectively.
For example, let’s suppose you want to simulate a 30 nm nMOS made of MoSe2. Supposing that MoSe2 has a relative effective mass for electrons equal to 0.6, a relative effective mass for holes equal to 0.71 and a bandgap of 1.13 eV, the code has to be changed accordingly:
FLAKE=TMD(30.0,”n”);
FLAKE.me=0.6
FLAKE.mh=0.71
FLAKE.Egap=1.13
A GUI version of the script can be found here.
Here the script and here the module.