Enhancing MoS₂ Electronic Performance with Solid-State Lithium-Ion Electrolyte Contacts through Dielectric Screening

The high electrical contact resistance at the metal-semiconductor interface hinders the practical application of two-dimensional (2D) semiconductor electronics in the postsilicon era. Conventional strategies toward Ohmic contact involve optimizing contact electrode materials. In this work, we utilize the band structure tunability of a 2D semiconductor by introducing a high dielectric constant gate dielectric to optimize the Schottky barrier height and width. Here, the dielectric screening effect induced by a solid-state lithium-ion electrolyte significantly reduces the Schottky barrier height to 2.7 meV. The resulting MoS₂ transistor achieves a subthreshold swing of 84 mV/dev and a drastically reduced contact resistance of 4.36 kΩ μm. The contact properties of the device under operational conditions are studied by in situ Kelvin probe force microscopy. Furthermore, the device demonstrates promising photodetection capabilities for visible and near-infrared light along with a fast response time. This work presents an approach to enhancing dielectric contacts in 2D semiconductors for advancing high-performance electronic and optoelectronic devices.