Contact-engineered reconfigurable two-dimensional Schottky junction field-effect transistor with low leakage currents

Two-dimensional (2D) materials have been considered promising candidates for future low power-dissipation and reconfigurable integrated circuit applications. However, 2D transistors with intrinsic ambipolar transport polarity are usually affected by large off-state leakage currents and small on/off ratios. Here, we report the realization of a reconfigurable Schottky junction field-effect transistor (SJFET) in an asymmetric van der Waals contact geometry, showing a balanced and switchable n- and p-unipolarity with the I ds on/off ratio kept >10 6 . Meanwhile, the static leakage power consumption was suppressed to 10 −5 nW. The SJFET worked as a reversible Schottky rectifier with an ideality factor of ~1.0 and a tuned rectifying ratio from 3 × 10 6 to 2.5 × 10 −6 . This empowered the SJFET with a reconfigurable photovoltaic performance in which the sign of the open-circuit voltage and photo-responsivity were substantially switched. This polarity-reversible SJFET paves an alternative way to develop reconfigurable 2D devices for low-power-consumption photovoltaic logic circuits. Here, the authors report the realization of WSe 2 Schottky junction field-effect transistors with asymmetric multi-layer graphene and WTe 2 van der Waals contacts, enabling reconfigurable polarity, low off-state currents, near-ideal rectifying behaviour and bipolar photovoltaic response.