▎ 摘　　要

heat transfer across interfaces of graphene and polar dielectrics (e.g.; SiO2) could be Mediated by direct: phonon coupling, as well as electronic coupling with remote interfacial phonons (RIPs). To understand-the relative contribution of each component, we develop a new pump probe technique called voltage-modulated thermorefleetance (VMTR) to accurately measure the change-of interfacial: thermal conductance under an electrostatic field. We employed VMTR on top gates of graphene field-,effect-transistors. and find that the thermal conductance of SiO2/graphene/SiO2 interfaces increases by up to Delta G approximate to 0.8 MW M-2 K-1 under electrostatic fields of <0.2 V nm(-1). We propose two possible explanations for-the small observed Delta G. First, because the applied electrostatic field induces charge carriers in graphene, out VMTR measurements could originate from heat transfer-between the charge carriers in graphene and RIPs in SiO2. Second, the increase in heat conduction could be caused by better conformity of graphene interfaces under electrostatic pressure exerted by the induced charge carriers. Regardless of the origins of the observed Delta G, our VMTR measurements eStablish, an upper limit for heat transfer from unbiased graphene to SiO2 substrates via RIP scattering; for example, only <2% of the interfacial heat transport is facilitated' y RIP scattering even at a carrier concentration of similar to 4 X 10(12) cm(-2).