Lateral Growth of MoS₂ 2D Material Semiconductors Over an Insulator Via Electrodeposition

Abstract

Developing novel techniques for depositing transition metal dichalcogenides is crucial for the industrial adoption of 2D materials in optoelectronics. In this work, the lateral growth of molybdenum disulfide (MoS2) over an insulating surface is demonstrated using electrochemical deposition. By fabricating a new type of microelectrodes, MoS2 2D films grown from TiN electrodes across opposite sides are connected over an insulating substrate, hence, forming a lateral device structure through only one lithography and deposition step. Using a variety of characterization techniques, the growth rate of MoS2 is shown to be highly anisotropic with lateral to vertical growth ratios exceeding 20‐fold. Electronic and photo‐response measurements on the device structures demonstrate that the electrodeposited MoS2 layers behave like semiconductors, confirming their potential for photodetection applications. This lateral growth technique paves the way toward room temperature, scalable, and site‐selective production of various transition metal dichalcogenides and their lateral heterostructures for 2D materials‐based fabricated devices.

Phase-Change Memory by GeSbTe Electrodeposition in Crossbar Arrays

“…The rate of growth at the edges is likely to be enhanced by the surface effect of SiO 2 sidewalls and the change from planar diffusion to semispherical diffusion once the 200 nm deep cell is filled with PCM. Surface enhancement in the deposition rate near SiO 2 surfaces has also been reported previously. , The AFM profile presented in Figure d shows that the shape of the sidewalls is angled. The angled shape of the sidewalls is caused by the isotropic wet etching, which was performed subsequent to dry etching in a two-step etching process (Figure S1).…”

“…Surface enhancement in the deposition rate near SiO 2 surfaces has also been reported previously. 41,42 The AFM profile presented in Figure 2d shows that the shape of the sidewalls is angled. The angled shape of the sidewalls is caused by the isotropic wet etching, which was performed subsequent to dry etching in a two-step etching process (Figure S1).…”

Electrodeposited WS2 monolayers on patterned graphene

“…Overall, it is clear that the film is composed of well-ordered 2D layers and the layer ordering of a particular layer tends to follow that of previous layers. It was noticed that the horizontal layer ordering changes slightly in some regions where the thickness is higher [52]. Figures 4(c) and (d) show high resolution TEM images taken via bright field for a film grown for 10 s. These films are observed to be composed of 1-2 layers only.…”

Atomic-Void van der Waals Channel Waveguides

“…Fabrication of such atomically thin out-of-plane channel waveguides is not straightforward. However, we expect that as progress with lateral growth, vertical alignment, nanofabrication and anisotropic etching evolves, high quality structures with <30 nm features can be obtained. Small fabrication imperfections while adding to insertion loss are not expected to influence mode dispersion.…”