Environmental graphene conductivity sensing using terahertz time-domain reflection spectroscopy

We demonstrate how reflection terahertz time-domain spectroscopy (THz-TDS) can be used to measure conductivity of large area graphene films through silicon substrate. This through-substrate approach in turn allows an unhindered access to the graphene top surface and thus, opens up pathways to perform in situ and in-operando THz-TDS using environmental cells.