Inducing Strong Light–Matter Coupling and Optical Anisotropy in Monolayer MoS₂ with High Refractive Index Nanowire

Abstract

Mixed-dimensional heterostructures combine the merits of materials of different dimensions; therefore, they represent an advantageous scenario for numerous technological advances. Such an approach can be exploited to tune the physical properties of two-dimensional (2D) layered materials to create unprecedented possibilities for anisotropic and high-performance photonic and optoelectronic devices. Here, we report a new strategy to engineer the light−matter interaction and symmetry of monolayer MoS 2 by integrating it with one-dimensional (1D) AlGaAs nanowire (NW). Our results show that the photoluminescence (PL) intensity of MoS 2 increases strongly in the mixed-dimensional structure because of electromagnetic field confinement in the 1D high refractive index semiconducting NW. Interestingly, the 1D NW breaks the 3-fold rotational symmetry of MoS 2 , which leads to a strong optical anisotropy of up to ∼60%. Our mixed-dimensional heterostructure-based phototransistors benefit from this and exhibit an improved optoelectronic device performance with marked anisotropic photoresponse behavior. Compared with bare MoS 2 devices, our MoS 2 /NW devices show ∼5 times enhanced detectivity and ∼3 times higher photoresponsivity. Our results of engineering light−matter interaction and symmetry breaking provide a simple route to induce enhanced and anisotropic functionalities in 2D materials.

Recent developments in the state-of-the-art optoelectronic synaptic devices based on 2D materials: a review

“…2D-1D heterostructure based devices Unlike bulk crystals, layered materials like TMDCs have very short light-matter interaction lengths and defect-mediated nonradiative electron-hole recombination, resulting in poor luminescence quantum yield. 236 Therefore, TMDC-based optoelectronic devices suffer from poor performance. Several techniques have been adopted to boost the light-matter coupling in 2D materials, like introducing plasmonic structures, 237 waveguides, and Fabry-Perot optical cavities.…”

“…238 However, research suggests that plasmonic structures based on 1Dnanowires (NWs) and nanotubes are most efficient in improving the light-matter coupling in TMDCs and other 2Dmaterials. 227,236 Phototransistors based on 1D-graphene heterostructures have shown excellent optoelectronic properties. Graphene-based optoelectronic devices exhibit a modest photoresponsivity of a few MA W À1 , which can be enhanced to ultra-high values of 10 6 A W À1 through appropriate hybridization with 1D materials.…”

Contact Geometry-Dependent Excitonic Emission in Mixed-Dimensional van der Waals Heterostructures

“…This limitation primarily arises from a lack of detailed information regarding band alignment and charge transfer mechanisms, which are critically dependent on the atomic configuration at the heterojunction interface and essential for modulating excitonic behaviors within these structures. 15,16 Advancing our understanding in this domain is imperative as it would significantly enhance the design landscape, offering the potential to manipulate emission properties alongside the native photonic confinement or routing functionalities inherent to 1D-2D vdW heterostructures. 17 Comprising various crystallographic planes with different energies, the sidewall facets of a nanowire dictate the overall physical properties, including optical and electronic transport phenomena.…”

Direct Epitaxial Growth of InP Nanowires on MoS2 with Strong Nonlinear Optical Response

“…III–V semiconductor nanowires (NWs) possess excellent light trapping properties, low density of crystal defects, long-term stability, high carrier mobility, and relaxed lattice matching conditions due to their small footprint. − These unique properties make NWs promising and suitable to be grown on different foreign substrates, including atomically thin 2D materials, e.g., graphene and MoS 2 . − Intriguingly, when 1D NWs are combined with 2D TMDCs having mechanical flexibility and tunable optical properties, the mixed-dimensional heterostructure can produce high-performance photonic and optoelectronic devices with complementary characteristics. , However, controlling the growth of NWs on 2D materials for achieving high vertical yield is still very challenging due to the absence of nucleation sites. Additionally, the stability of 2D materials after NW growth (especially in TMDCs) is another important issue to consider for utilizing the benefit of the mixed-dimensional heterostructures.…”

“…17−23 Intriguingly, when 1D NWs are combined with 2D TMDCs having mechanical flexibility and tunable optical properties, the mixed-dimensional heterostructure can produce high-performance photonic and optoelectronic devices with complementary characteristics. 24,25 However, controlling the growth of NWs on 2D materials for achieving high vertical yield is still very challenging due to the absence of nucleation sites. Additionally, the stability of 2D materials after NW growth (especially in TMDCs) is another important issue to consider for utilizing the benefit of the mixed-dimensional heterostructures.…”