Vertical Nonvolatile Schottky-Barrier-Field-Effect Transistor with Self-Gating Semimetal Contact

Emerging 2D nonvolatile Schottky-barrier-field-effect transistors (NSBFETs) are envisaged to build a promising reconfigurable in-memory architecture to mimic the brain. Herein, a vertically stacked multilayered graphene (MGr)-molybdenum disufide (MoS₂)-tungsten ditelluride (WTe₂) NSBFET is reported. The semimetal WTe₂ with the charge-trapping effect enables the simultaneous integration of the electrode and the self-gating function. The effective Schottky barrier height offset ΔΦ_B is programed from ΔΦ_B-p = 132.6 meV to ΔΦ_B-n = 109.4 meV, inducing the reversed built-in electric field to make the NSBFET, so as to provide one with a multifunctional platform to integrate the nonvolatility and the reconfigurable self-powered photo response. The reversible open-circuit voltages of NSBFET synapse are programmed from −0.1 to 0.25 V and the self-powered responsivity with reversed signs is tuned from 290 to −50 mA W⁻¹, which enables the representation of a signed weight in a single device to enrich multiple optical sensing and computing capabilities.