Synthetic Lateral Metal-Semiconductor Heterostructures of Transition Metal Disulfides

Abstract

The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters.ABSTRACT: Lateral heterostructures with planar integrity form the basis of two-dimensional (2D) electronics and optoelectronics. Here we report that, through a twostep chemical vapor deposition (CVD) process, highquality lateral heterostructures can be constructed between metallic and semiconducting transition metal disulfide (TMD) layers. Instead of edge epitaxy, polycrystalline monolayer MoS 2 in such junctions was revealed to nucleate from the vertices of multilayered VS 2 crystals, creating one-dimensional junctions with ultralow contact resistance (0.5 kΩ·μm). This lateral contact contributes to 6-fold improved field-effect mobility for monolayer MoS 2 , compared to the conventional on-top nickel contacts. The all-CVD strategy presented here hence opens up a new avenue for all-2D-based synthetic electronics. See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles. Corresponding SEM images. Inset in panel f is the zoomed-in SEM image of a lateral VS 2 −MoS 2 interface (scale bar 2 μm). (g, h) Raman and PL spectra on the central VS 2 region and the surrounding MoS 2 region (blue and red curves, respectively) for the MoS 2 −VS 2 heterostructures. (i) Schematic illustration of MoS 2 growth on presynthesized multilayered VS 2 .

Synthesis of 2H‐1T′ WS2‐ReS2 Heterophase Structures with Atomically Sharp Interface via Hydrogen‐Triggered One‐Pot Growth

“…This structural feature shows great difference from that observed in MoS 2 ‐NbS 2 and MoTe 2 ‐MoS 2 heterophase structures reported recently, where polycrystalline MoS 2 and MoTe 2 are always obtained due to their splicing with random orientations. [ 20,38 ] In this respect, the growth process of WS 2 ‐ReS 2 heterojunction should have an entirely different epitaxial growth model.…”

“…At present, the defect, surface‐deposition, in‐phase alloying, and polycrystalline merging, which bring the 2D TMDs heterophase structures a low‐quality interface, are the primary problems during synthesis of these heterophase structures. [ 36–38 ] Thus, developing an effective approach to synthesize 2D TMDs heterophase structures with clear, defect‐free, sharp, and seamless interface is essential to explore their fundamental properties and device applications.…”

Sub‐Millimeter‐Scale Monolayer p‐Type H‐Phase VS2

“…So far the T phase VS 2 has been widely studied due to its high conductivity, excellent electrocatalytic activity, and ferromagnetism. [ 11–14 ] It is worth noting that H‐phase VS 2 has aroused wide concern for its semiconductor property and larger magnetic moment than the T phase, which provides opportunities for potential application of electronic and spintronic devices. [ 15 ] It is predicted that the H‐phase VS 2 is the low‐energy ground state and has a large magnetic moment, which implies that H‐phase VS 2 will possibly show intrinsic 2D ferromagnetism.…”

Approaching ohmic contact to two-dimensional semiconductors

“…The fabrication processes are compatible with the standard state-of-the-art fabrication of Si-based semiconductor techniques and this approach is scalable and applicable to other TMD materials, with MoS 2 and WS 2 particularly demonstrated as two examples. Afterwards, the lateral epitaxy of other metallic 2D and semiconducting 2D materials to form the edge contact are reported (1T'-MoTe 2 and H-MoTe 2 [71], VS 2 and MoS 2 [72], NbS 2 and WS 2 [73]).…”