Waveguide-Integrated MoS<sub>2</sub> Field-Effect Transistors on Thin-Film Lithium Niobate with High Responsivity and Ultra-Low Dark Current
Fan Yang, Youtian Hu, Jiale Ou, Qingyun Li, Xiangxing Xie, Huangpu Han, Changlong Cai, Shuangchen Ruan, Bingxi Xiang
Abstract
This study investigates the photoelectric performance of MoS 2 -based field-effect transistors (FETs) integrated with a thin-film lithium niobate (TFLN) waveguide platform. The MoS 2 FET demonstrates high photodetection capabilities across a broad wavelength range from visible to near-infrared (up to 1550 nm). By adjusting the gate voltage from 0 V to −25 V, the dark current is reduced by over 6 orders of magnitude, reaching approximately 2 pA. Under 635 nm illumination, the device achieves a maximum responsivity of 940 A/W (at an input power of 35 pW), an on/off ratio ( I light / I dark ) of 10 5, and a detectivity of 6.27 × 10 14 W –1 . Significant photoresponse is also observed at telecommunication wavelengths with a responsivity of 68.7 mA/W and a detectivity of 4.58 × 10 10 W –1 at 1310 nm. Additionally, the response times is measured to be under 300 μs across all tested wavelengths. The combination of two-dimensional material FET and TFLN offers an attractive platform for realizing high-performance optoelectronic devices and multifunctional integrated photonic circuits.