Reconfigurable InSe Electronics with van der Waals Integration

As a 2D semiconductor, indium selenide (InSe) has shown great potentials in electronic and optoelectronic applications attributed to high carrier mobility and moderately large bandgap. However, switchable doping polarity of intrinsic InSe by electrical gating is not yet demonstrated, which is essential for applications in complementary electronics. In this work, the ambipolarity of InSe is realized and exploited through the van der Waals (vdW) integration with metal electrodes, which gets rid of the Fermi-level pinning at the metal/semiconductor interfaces. On this basis, InSe field-effect transistors (FETs) with controllable polarities are reconfigured with a dual-gate structure, functioning as both unipolar FETs and p–n diodes. The p- and n-type operations of the unipolar FETs are dynamically switched with on–off ratios of 10⁶ and 10⁹, respectively. Meanwhile, p–n diodes with a rectification ratio of 10⁶ and high photodetection performance are also demonstrated. This work paves a promising way for InSe-based reconfigurable complementary electronics and optoelectronics.