Measurement of thermal contact resistance between CVD-grown graphene and SiO2 by null point scanning thermal microscopy

For graphene-based electronic devices, it is crucial to measure and analyze the thermal contact resistance between the graphene and the insulating layer. Herein, we measure the thermal contact resistance between CVD-grown graphene and a SiO₂ layer using null point scanning thermal microscopy (NP SThM), which can profile the temperature distribution quantitatively with nanoscale spatial resolution by preventing the influence of both the heat flux through the air gap and the variation of sample surface properties such as hydrophilicity. Through the comparison of the temperature jump across the interface of the electrically heated graphene and SiO₂ layer with the temperature profile without the thermal contact resistance modelled with finite element method, the thermal contact resistance between the graphene and SiO₂ is obtained as 10 × 10^-8 ~ 45 × 10^-8 m²K/W.