Why don't you try the software on nanoHUB: https://nanohub.org/ ?

Thanking you Sir for reply

Nanohub have NanoTCAD ViDES softwere for graphene simulation but it is not terminating for graphene. Will I define graphene as a channel material in silvaco.

you can find from the link such an effort:

http://portal.fke.utm.my/fkelibrary/files/rinabintianuar/2012/358_RINABINTIANUAR2012.pdf

please read following. you can can define new material with certain limitations.I think tcad wont support dirac two dimensional material but try user defined functions.

 https://www.researchgate.net/post/How_to_define_Graphene_in_silvaco_Can_anyone_please_suggest_me

Mohammad Karbalaei Hi. Defining Graphene in Silvaco is not so easy. But I have seen in some papres they defined it by "material" statement in the software. In my idea it is better to find experimental data about graphene and try to calibrate your device, the defined material with eperimaantal one and use it as Graphene in your work. I'm at your service for any other questions

REGION num=XX USER.MATERIAL=Graphene y.min=XX y.max=YY

MATERIAL material=graphene USER.GROUP=semiconductor \

eg300=1e-4 nc300=1.0e10 nv300=1.0e10 permittivity=4.6 \

mun=1e5 mup=1e5

MOBILITY material=graphene deltaep.pfmob=???? betap.pfmob=????