Supplementary information for: Deterministic assembly of arrays of lithographically defined WS_2 and MoS_2 monolayer features directly from multilayer sources into van der Waals heterostructures

One of the major challenges in the van der Waals (vdW) integration of 2D
materials is achieving high-yield and high-throughput assembly of
pre-defined sequences of monolayers into heterostructure arrays.
Mechanical exfoliation has recently been studied as a promising technique
to transfer monolayers from a multilayer source synthesized by other
techniques, allowing the deposition of a wide variety of 2D materials
without exposing the target substrate to harsh synthesis conditions.
Although a variety of processes have been developed to exfoliate the 2D
materials mechanically from the source and place them deterministically
onto a target substrate, they can typically transfer only either a
wafer-scale blanket or one small flake at a time with uncontrolled size
and shape. Here we present a method to assemble arrays of lithographically
defined monolayer WS2 and MoS2 features from multilayer sources and
directly transfer them in a deterministic manner onto target substrates.
This exfoliate–align–release process—without the need of an intermediate
carrier substrate—is enabled by combining a patterned, gold-mediated
exfoliation technique with a new optically transparent, heat-releasable
adhesive. WS2/MoS2 vdW heterostructure arrays produced by this method show
the expected interlayer exciton between the monolayers. Light-emitting
devices using WS2 monolayers were also demonstrated, proving the
functionality of the fabricated materials. Our work demonstrates a
significant step towards developing mechanical exfoliation as a scalable
dry transfer technique for the manufacturing of functional, atomically
thin materials.