Figure 4
From: Observation of a giant two-dimensional band-piezoelectric effect on biaxial-strained graphene
Application of two-dimensional piezoelectric graphene NEMS for energy harvesting and sensing. (a) Schematic band structure of the open circuit of the piezoelectric nanogenerator under applied mechanical load. The local Fermi level is marked by a red dashed dot line at the interfaces. The hypothesized bandgap location in the suspended graphene is marked by ‘Δ’. (b) Output voltage of the graphene membrane-based NEMS nanogenerator under different mechanical loads. The times at which the AFM tip approaches and withdraws from the graphene membrane is marked by solid and dashed arrows, respectively. (c) Short circuit current of the suspended graphene membrane nanogenerator. The shaded area marks the time during which the AFM scanning occurs. (d) Two terminal resistance of the piezoresistive pressure sensor versus mechanical load. The error bar represents the s.d. AFM, atomic force microscope; NEMS, nanoelectromechanical systems.
