Low-Temperature and Large-Scale Production of a Transition Metal Sulfide Vertical Heterostructure and Its Application for Photodetectors

Abstract

The conventional synthesis of two-dimensional (2D) transition metal dichalcogenide (TMDC) heterostructures is low yielding and lack the heterojunction interface quality. The chemical vapor deposition (CVD) techniques have achieved highquality heterostructure interfaces but require a high synthesis temperature (>600 °C) and have a low yield of heterostructures. Therefore, the large scale and high interface quality of TMDC heterojunctions using low-temperature synthesis methods are in demand. Here, high-quality, wafer-scale MoS 2 and WS 2 heterostructures with 2D interfaces were prepared by a one-step sulfurization of the molybdenum (Mo) and tungsten (W) precursors via plasma-enhanced CVD at a relatively low temperature (150 °C). The 4 inch wafer-scale synthesis of the MoS 2 −WS 2 heterostructures was validated using various spectroscopic and microscopic techniques. Further, the photocurrent generation and photoswitching phenomenon of the so-obtained MoS 2 −WS 2 heterostructures were studied. The photodevice prepared by the MoS 2 −WS 2 heterostructures at 150 °C showed a photoresponsivity of 83.75 mA/W. The excellent photoresponse and faster photoswitching highlight the advantage of MoS 2 −WS 2 heterostructures toward advanced photodetectors.

Lattice Defect Engineering Enables Performance-Enhanced MoS2 Photodetection through a Paraelectric BaTiO3 Dielectric

“…Owing to their excellent optical and electronic properties influenced by their quantum size and confinement effects, two-dimensional (2D) materials have broad promising applications in optoelectronic devices. − One prominent representative in this regard is 2D molybdenum disulfide (MoS 2 ), which is persistent in light detection because it possesses particular features, such as thickness-dependent tunable band structure, atomic-level interface, and high compatibility with large-scale fabrication . The photocurrent ( I ph ) for a photoconductivity detector corresponds to I ph = e (μ n Δ n + μ p Δ p )· A · V / L , where e , μ, Δn ( Δp ), and V are the elementary charge, mobility, light generated free electron (hole) densities, and applied bias voltage, respectively; and A and L are the cross-sectional area and length of the detector, respectively.…”

The first progress of plasma-based transition metal dichalcogenide synthesis: a stable 1T phase and promising applications

“…5d . 47 Two as-fabricated MWVH photodetectors were prepared at 150 °C (150D), and MWVHs were further annealed at 300 °C (300D). The photocurrent generation at 150D under light illumination of wavelengths ( λ = 420, 530, and 660 nm) is larger than that at 300D except in the case of 1050 nm.…”

Transition Metal Dichalcogenides (TMDCs) Heterostructures: Synthesis, Excitons and Photoelectric Properties

“…At the same time, it retains the advantages of significant area synthesis and clean interface. [39] The growth of type I and II heterostructures were controlled by adjusting temperature, while Chen et al realized the selective growth of vertical heterostructures based on WS 2 . In the growth process, they mainly used the method of stacking sulfurized metal W film on Mo film.…”