Observation of reduced 1/f noise in graphene field effect transistors on boron nitride substrates

We have investigated the low frequency (f) flicker (also called 1/f) noise of single-layer graphene devices on h-BN (placed on SiO₂/Si) along with those on SiO₂/Si. We observe that the devices fabricated on h-BN have on average one order of magnitude lower noise amplitude compared with devices fabricated on SiO₂/Si despite having comparable mobilities at room temperature. We associate this noise reduction to the lower densities of impurities and trap sites in h-BN than in SiO₂. Furthermore, the gate voltage dependent noise amplitude shows a broad maximum at Dirac point for devices on h-BN, in contrast to the M-shaped behavior showing a minimum at Dirac point for devices on SiO₂, consistent with the reduced charge inhomogeneity (puddles) for graphene on h-BN. This study demonstrates that the use of h-BN as a substrate or dielectric can be a simple and efficient noise reduction technique valuable for electronic applications of graphene and other nanomaterials.