Electromechanical Sensing of Substrate Charge Hidden under Atomic 2D Crystals

The functionality of graphene and other two-dimensional materials in electronic devices is highly influenced by the film-substrate charge transfer affecting local carrier density. We demonstrate that charges buried under the few layer graphene on/in the insulating substrate can be detected using electromechanical actuation of the conductive atomically thin layers, allowing measurements of areal density of film-substrate transferred charges under few layer graphene and MoS2 suspended films.