Hybrid MoS₂-gap-mode metasurface photodetectors

Abstract

Two-dimensional molybdenum disulfide (MoS2) 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.

Review of Anisotropic 2D Materials: Controlled Growth, Optical Anisotropy Modulation, and Photonic Applications

“…Recently, the anisotropic Au metasurfaces, [ 211 ] as a novel approach, has been adopted to develop polarization‐sensitive, fast‐response MoS 2 ‐based photodetectors. [ 212 ] While the stripe array shows stronger anisotropy, the large length of the stripe may cause a mismatch between the LSP resonant frequency and the absorption band of 2D materials. To address this issue, micropatterned gratings composed of plasmonic materials were developed (Figure 9d).…”

Broadband, Ultra-High-Responsive Monolayer MoS2/SnS2 Quantum-Dot-Based Mixed-Dimensional Photodetector

“…Transition metal dichalcogenides (TMDs) have gained significant attention since the discovery of graphene in 2004. TMDs are being investigated as possible options for next-generation optoelectronic and electrical devices due to their distinguished properties, which include atomic thinness, tunable band gap, high mobility, and excellent electronic and optical properties. ,, Molybdenum disulfide (MoS 2 ) is one of the most widely used and investigated 2D TMDs because of its advantages such as strong in-plane carrier mobility, a layer-dependent band gap, high absorption coefficient, and excellent stability. − Monolayer MoS 2 is extensively utilized for the fabrication of photodetectors due to particular optical properties which are not found in bulk materials, such as strong-light matter interaction, high mobility (200 cm 2 /V·S), direct band gap, and so on. − MoS 2 in a monolayer exhibits a direct band gap of ∼1.8 eV because of quantum confinement, but MoS 2 in bulk has an indirect band gap of ∼1.3 eV. , Wang et al demonstrated a visible–near-infrared (NIR) light detector based on a monolayer MoS 2 /Si heterostructure, showing a detectivity of 10 13 Jones and an ultrafast rise time (∼3 μs) . Zhou et al constructed a MoS 2 /SnSe 2 van der Waals heterostructure-based visible light photodetector with a high responsivity of 9 × 10 3 A/W .…”

Direct growth of monolayer 1T–2H MoS2 heterostructures using KCl-assisted CVD process

“…Molybdenum and tungsten-based transition metal dichalcogenides (TMDs) monolayer semiconductors are being exhaustively studied as unique systems to develop numerous applications, including electronic/optoelectronic devices, electrocatalysis, spintronics, and novel platforms to study unconventional quantum phenomena. In particular, molybdenum disulfide (MoS 2 ) in the 2H structural phase exhibits remarkable electronic and optoelectronic properties exploited to develop different device configurations, including transistors [1], photodetectors [2,3], photovoltaics [4], singlephoton emitters [5], electrically tunable lightemitters [6] and lasers [7].…”