Graphene Conductivity Mapping using Terahertz Time-Domain Reflection Spectroscopy

Graphene conductivity mapping was successfully demonstrated using terahertz time-domain spectroscopy (THz-TDS) operating in transmission geometry. In order to cater for a greater range of substrates and scenarios where transmission geometry becomes prohibitive, here we demonstrate conductivity mapping of large area chemical vapor deposited (CVD) graphene films on sapphire. We validate the technique against measurements performed using the transmission based THz- TDS.