2D HEMT Additional functions

● HEMT special functions

1. trap regions
You can refer to the $traps command.

2. Poole-Frenkel model (use field dependent mobility)
You can refer to the $useevprofile, $xend and $yend commands.

3. Thermal
You can refer to the $thermaldiff, $heatiterative, $heatbndistance and $usemuTfactor commands.