▎ 摘　　要

Controllable biaxial strain is delivered to monolayer graphene prepared by chemical vapor deposition via applying an electric field to the underlying piezoelectric [Pb(Mg1/3Nb2/3)O-3] (0.7)-[PbTiO3](0.3) substrate. The effects of tunable strain on the Raman spectra of graphene are investigated in reversible and real-time manners. Such strain can result in a blue shift in 2D band of graphene. The calculations based on the Gruneisen parameter identify the actual biaxial strain to graphene, leading to a continuous 2D band shift, which is detected during the retention of bias voltage. The physical mechanism behind this unique Raman behavior is discussed. (C) 2013 AIP Publishing LLC.