High‐Sensitivity Infrared Photoelectric Detection Based on WS₂/Si Structure Tuned by Ferroelectrics

Abstract As one of the typical transition‐metal dichalcogenides with distinct optical and electrical properties, WS₂ exhibits tremendous potential for optoelectronic devices. However, its inherent band gap range limits the application in the infrared region. To overcome this draw‐back and improve the sensitivity, P(VDF‐CTFE) is used as a ferroelectric gate to control the states of WS₂/Si junctions and achieve an enhanced infrared photodetection. The polarization electric field not only broadens the range of absorption wavelength (405–1550 nm) but also greatly promotes the sensitivity of lateral photovoltaic effect (LPE) (from 198.6 to 503.2 mV mm⁻¹). This phenomenon is attributed to the reduction of WS₂ band gap and the change of potential barrier at the interface of the junction. Meanwhile, the response speed is improved significantly due to the increase of carrier initial kinetic energy. This new scheme for ferroelectric tuned LPE opens up a way to realize high‐sensitivity, ultrafast, and stable infrared photodetection.