Controllable One-Pot Growth of MoSe₂/WSe₂ Lateral and Vertical Heterostructures by Facile Chemical Vapor Deposition

Abstract

The controllable growth of single-crystal lateral and vertical heterostructures based on two-dimensional transition metal dichalcogenides (TMDs) is more difficult than the preparation of ordinary TMDs. In this study, we develop a facile chemical vapor deposition (CVD) scheme for the preparation of large-area and single-crystal WSe2/MoSe2 heterostructures on amorphous SiO2/Si substrates. In addition to using a customized temperature profile and introducing H2 flow, we also make a facile placement for the transition metal precursors: the Mo and W sources are placed on either side below the growing substrate for the growth of lateral heterostructures, while the Mo source is stacked with the W source for the growth of vertical heterostructures. The combination of these strategies helps the controllable lateral (or vertical) epitaxy of different TMD materials. Both lateral and vertical WSe2/MoSe2 heterostructures are of high quality and homogeneity, as revealed by optical and structural characterizations. The photodetectors based on lateral heterostructures at self-driven mode exhibit a maximum photoresponsivity of 45 A/W, a detectivity of 9.4 × 1014 Jones, and a fast response time of 22.5 ms. This one-pot and facile CVD epitaxy strategy may pave the way to fabricating large-area and high-quality lateral and vertical TMD heterostructures, which are of great importance in electronics and optoelectronics.

Light‐Induced Ferroelectric Modulation of p‐n Homojunctions in Monolayer MoS2

“…In this case the deterministic transfer method cannot be easily applied, and different bottom‐up fabrication methods should be employed. [ 8–10 ] Of particular relevance in designing novel electronic and optoelectronic devices are TMD‐based p‐n homojunctions. In these systems, perfect lattice matching, continuous band bending, and efficient charge transfer are highly beneficial for carrier transport and separation at the junction.…”