title: Diffusion-Mediated Synthesis of MoS2/WS2 Lateral Heterostructures.
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.
authors.affiliation: Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , 6 Science Drive 2, Singapore , 117546.|Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Kevin
authors.initials: K
authors.lastname: Bogaert
authors.affiliation: Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , 6 Science Drive 2, Singapore , 117546.
authors.forename: Song
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Jordan
authors.initials: J
authors.lastname: Chesin
authors.affiliation: Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.|Department of Biology and Chemistry, Justus-Liebig-University Giessen , Heinrich-Buff-Ring 17-19, 35392 Giessen, Germany.
authors.forename: Denis
authors.initials: D
authors.lastname: Titow
authors.affiliation: Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Silvija
authors.initials: S
authors.lastname: Gradečak
authors.affiliation: Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , 6 Science Drive 2, Singapore , 117546.|Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore , 117542.|Department of Biomedical Engineering, National University of Singapore , 9 Engineering Drive 1, Singapore , 117575.
authors.forename: Slaven
authors.initials: S
authors.lastname: Garaj
keywords: Transition metal dichalcogenides; chemical vapor deposition; diffusion; heterostructures