1. The work function of the metalic region will determine where is the zero value of the gate potential. Thus, the effect of the work function is to shift the gate potential by a constant. You cannot set this parameter, and you need to make such corrections as post analysis.
I.e. work function of electrode is 4 eV, work function of gate is 5 eV, then you must add -1 V to you gate potential axis as post analysis.
2. You can set this parameter in the script generator tool in vnl, see forinstance the graphene device tutorial or the ATKDeviceTutorial
Can you please tell me how to determine the work function for electrode and gate for performing such post analysis
-- Thank you