Hybrid MoS$_2$-gap-mode metasurfaces photodetectors

TL;DR

This paper presents a novel hybrid metasurface-MoS2 photodetector that leverages electromagnetic field confinement and optical anisotropy to achieve enhanced, polarization-sensitive, fast-response detection in an ultra-compact device.

Contribution

It introduces the integration of metasurfaces with 2D MoS2 to create highly compact, polarization-sensitive photodetectors with improved performance and response speed.

Findings

Enhanced photocurrent due to electromagnetic field confinement

Fast detection speed achieved in hybrid device

Polarization sensitivity controlled by metasurface anisotropy

Abstract

Two-dimensional molybdenum disulfide (MoS$_2$) featuring atomically thin thickness and unique electronic structure with favorable bandgap has been widely recognized as an attractive new material for the development of the next generation of ultra-compact, light-weight optoelectronic components. In parallel, the recently emerged metasurfaces have demonstrated exceptional controllability over electromagnetic field within ultra-compact subwavelength dimension offering an unprecedented approach to improve the performance of optoelectronic devices. In this work, we are proposing an integration of metasurfaces with 2D semiconductor materials to achieve polarization sensitive, fast-response photodetectors. The reported devices are among the most compact hybrid MoS2-gap-plasmon metasurface detectors. Relying on the significant electromagnetic field confinement provided by the metasurfaces to enhance light absorption and to reduce the surface states, which generally limit the photo-generated carriers lifetime, we measured enhanced photocurrent and a fast detection speed. Moreover, the strong optical anisotropy introduced by the metasurfaces is used to efficiently control the polarization sensitivity of the photodetector. This work provides a feasible and effective solution to improve the performance of two-dimensional materials based photodetectors.