Van der Waals device integration beyond the limits of van der Waals forces via adhesive matrix transfer

TL;DR

This paper introduces a novel adhesive matrix transfer method enabling direct, solvent-free integration of diverse 2D materials with dielectrics and device fabrication, overcoming limitations of traditional van der Waals interfaces.

Contribution

The authors present a single-step transfer technique that decouples transfer forces from van der Waals forces, allowing for scalable, clean, and versatile integration of 2D materials into electronic devices.

Findings

Enabled direct integration of various 2D materials with dielectrics.

Achieved scalable, aligned heterostructure formation.

Demonstrated flexible transistors with pristine interfaces.

Abstract

Pristine van der Waals (vdW) interfaces between two-dimensional (2D) and other materials are core to emerging optical and electronic devices. Their direct fabrication is, however, challenged as the vdW forces are weak and cannot be tuned to accommodate integration of arbitrary layers without solvents, sacrificial-layers or high-temperatures, steps that can introduce damage. To address these limitations, we introduce a single-step 2D material-to-device integration approach in which forces promoting transfer are decoupled from the vdW forces at the interface of interest. We use this adhesive matrix transfer to demonstrate conventionally-forbidden direct integration of diverse 2D materials (MoS2, WSe2, PtS2, GaS) with dielectrics (SiO2, Al2O3), and scalable, aligned heterostructure formation, both foundational to device development. We then demonstrate a single-step integration of monolayer-MoS2 into arrays of transistors. With no exposure to polymers or solvents, clean interfaces and pristine surfaces are preserved, which can be further engineered to demonstrate both n- and p-type behavior. Beyond serving as a platform to probe the intrinsic properties of sensitive nanomaterials without the influence of processing steps, our technique allows efficient formation of unconventional device form-factors, with an example of flexible transistors demonstrated.