Piezoelectrically modulated touch pressure sensor using a graphene barristor

A touch pressure sensor using a graphene-Si Schottky junction barristor gated with the piezoelectric polymer poly(vinylidenefluoride-cotrifluoroethylene) has been demonstrated that combines a high on-off ratio (over 10(2)) and low leakage current characteristics. The performance of this device was optimized by presetting the initial Fermi level of graphene using a polymer doping process. Sensing current modulation ratios up to 312% were achieved under 3 MPa touch pressure. (C) 2019 The Japan Society of Applied Physics