Diffusion-Mediated Synthesis of MoS2/WS2 Lateral Heterostructures

TitleDiffusion-Mediated Synthesis of MoS2/WS2 Lateral Heterostructures
Publication TypeJournal Article
Year of Publication2016
AuthorsBogaert, K, Liu, S, Chesin, J, Titow, D, Gradecak, S, Garaj, S
JournalNano Letters
Volume16
Issue8
Pagination5129 - 5134
Date Published2016/08//
ISBN Number1530-6984
Keywordsalloys, atomic layers, chemical vapor deposition, diffusion, epitaxial-growth, heterojunctions, heterostructures, inplane heterostructures, monolayers, nanosheets, optical-properties, Transition metal dichalcogenides, transition-metal dichalcogenides, tunable band-gap
Abstract

Controlled growth of two-dimensional transition metal dichalcogenide (TMD) lateral heterostructures would enable on demand tuning of electronic and optoelectronic properties in this new class of materials. Prior to this work, compositional modulations in lateral TMD heterostructures have been considered to depend solely on the growth chronology. We show that in-plane diffusion can play a significant role in the chemical vapor deposition of MoS2/WS2 lateral heterostructures leading to a variety of nontrivial structures whose composition does not necessarily follow the growth order. Optical, structural, and compositional studies of TMD crystals captured at different growth temperatures and in different diffusion stages suggest that compositional mixing versus segregation are favored at high and low growth temperatures, respectively. The observed diffusion mechanism will expand the realm of possible lateral heterostructures, particularly ones that cannot be synthesized using traditional methods.

Short TitleNano Lett.