High-performance van der Waals junction field-effect transistors utilizing organic molecule/transition metal dichalcogenide interface

Two-dimensional (2D) transition metal dichalcogenide (TMD) hetero PN junctions with a van der Waals (vdW) interface have received much attention, because PN diodes are basically important to control the vertical current across the junction. Interestingly, the same vdW PN junction structure can be utilized for junction field-effect transistors (JFETs) where in-plane current is controlled along the junction. However, 2D vdW JFETs seem rarely reported, despite their own advantages to achieve when good vdW junction is secured. Here, we present high-performance p-MoTe₂ JFETs using almost perfect vdW organic Alq₃/p-MoTe₂ junctions and demonstrate organic NPB/n-MoS₂ JFETs. The p- and n-channel JFETs stably show high mobilities of 60−80 and ∼800 cm²/V s, respectively, along with a high ON/OFF current ratio (>1 × 10⁵) and minimal gate leakage at 5 V even after a few months. Such performances are attributed to a quality vdW junction at organic layer/TMD interfaces.