Subthreshold Schottky-barrier transistor based on monolayer molybdenum disulfide

While the internet of things (IoT) enhances global connectivity through trillions of sensors, the sensory signals are weak and require precise amplification and rapid transmission via thin-film transistor (TFT) interfaces, which must uphold high voltage gain and wide operating frequency range. In this work, we demonstrate a source-gated transistor (SGT) architecture integrating chemical vapor deposition (CVD)-grown monolayer MoS₂ with thin high-k dielectrics. This transistor achieves subthreshold operation with high intrinsic gain and wide operating frequency range, even at an 80 nm channel-length (L_CH). The optimization of output resistance, transconductance and subthreshold swing yields an SGT intrinsic gain exceeding 2.4×10³, with no degradation as L_CH scales from 1000 nm down to 80 nm. Additionally, benefitting from the ultra-short 80 nm L_CH, microwave measurements show a high cut-off frequency of 208 MHz in the subthreshold regime. A monolithically integrated common-source amplifier operating in the subthreshold regime exhibits a high gain of 249 V/V at low supply voltage (0.5 V) and ultra-low power ( ~ 0.17 nW), indicating a promising path toward a universal high-performance transistor solution for high gain, high frequency, and ultra-low power applications.