Fig. 1: Device characterization.
a Schematic of MoS2-FeFET with P(VDF-TrFE) as ferroelectric gate, Gr/Au/Cr as Source, h-BN/Au/Cr as Drain 1, and Au/Cr as Drain 2. b Optical microscope photograph of the device. The red, black, and blue dashed lines outline MoS2, h-BN, and Gr, respectively. Scale bar: 5 μm. c Raman spectra for MoS2/h-BN and MoS2/Gr heterostructures. d, e PFM phase (d) and amplitude (e) images of P(VDF-TrFE) film after writing an “ECNU” shape with a biased conductive tip. Scale bar: 4 μm. f Polarization versus voltage (P–V) and transient current versus voltage (I-V) curves measured for Al/P(VDF-TrFE)/Al capacitor. The test frequency is 100 Hz. g, h Transfer curves of asymmetric Schottky-contacted MoS2-FeFET (g) and vertical tunneling FeFET (h) in a semi-log plot, measured at VDS = ± 0.3 V. i The retention characteristics of 22 intermediate conductance states in vertical tunneling MoS2-FeFET that is measured at VDS = −0.2 V.
