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

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.

Automated summary

By using P(VDF-CTFE) as a ferroelectric gate, the sensitivity and infrared detection performance of WS2/Si junctions have been successfully improved, allowing for broadening of the absorption wavelength range and enhancing the sensitivity of lateral photovoltaic effect. The significant improvement in response speed is attributed to the increase in carrier initial kinetic energy, providing a new approach for high-sensitivity, ultrafast, and stable infrared photodetection.