Very-wide electrothermal tuning of graphene nanoelectromechanical resonators

We report on the first demonstration of electrothermally tunable graphene nanoelectromechanical resonators via Joule heating. We fabricate single-, bi- and tri-layer graphene resonators (up to 136MHz) to study electrothermal effects on resonance characteristics. The tri-layer graphene resonator exhibits frequency upshift from 9.5MHz to 26.1MHz by electrothermal heating, resulting in tuning range up to 180%. The device temperature is carefully verified via anharmonic frequency shift of Raman modes, exhibiting temperature elevation up to 600K in tri-layer graphene device with Joule heating. This work proves that electrothermal effects could broadly tune graphene resonators with high efficiency.