Enhanced Electrical Interfaces in Flexible 2D Material Transistors via Liquid Metal and Ionic Liquid Injection

Abstract Contact engineering at the semiconductor–electrode and semiconductor–dielectric interfaces is critical to the performance of electronic devices, especially for delicate 2D semiconductors. Here, this study proposes a new paradigm of flexible field‐effect transistors featuring solid–liquid hybrid interfaces, in which liquid metal and ionic liquid, confined within microchannels, function as the source/drain electrodes and gate dielectric, respectively. These interfaces provide MoS₂ with undisturbed, atomically smooth electrical contacts, and enable efficient gate control via electric double layers. Benefiting from the inherent softness of liquids and their damage‐free processing, Fermi level pinning is significantly mitigated by the liquid metal, achieving a pinning factor |s| = 0.7. Meanwhile, the ionic liquid enables a subthreshold swing of 60.7 mV dec −1 , approaching the theoretical thermal limit. Furthermore, our flexible transistors demonstrate multifunctionality as enhanced logic gates, low‐voltage inverters, and ultra‐high‐linearity synaptic devices. This work underscores the promise of liquid‐enabled contact strategies for advancing low‐power, flexible electronics and soft robotic systems.