Wafer-scale inspection of graphene conductivity by THz near-field scanning: As-grown on sapphire and after transfer to SiO2/Si

We present THz near-field transmission measurements for CVD-grown 2" graphene mono-layer on sapphire before and after transfer to SiO
₂
/Si substrate. The capability to detect changes in the graphene electronic properties after the transfer reveal the potential of THz-measurements as a non-destructive inspection tool for large scale samples with micron-scale resolution.