For modelling graphene, the CST software includes both a graphene and a graphene-Eps model. The graphene model expressed in the CST with a thickness of 0.3 nm is considered a single layer of graphene, while the graphene-EPS model is expressed as a multilayer of graphene sheets with a suitable thickness. Whenever I use the ''graphene-EPS'' model and increase the chemical potential, it does not affect any changes while using the "graphene'' model. Even at 0 eV chemical potential, it reflects all waves.Now my question is: why does it reflect all waves, even in insulting phases? I suspect that I may have made mistakes while creating the graphene material.