Pinpoint pick-up and bubble-free assembly of 2D materials using PDMS/PMMA polymers with lens shapes

TL;DR

This paper introduces a lens-shaped polymer transfer system for assembling 2D materials, achieving bubble-free, clean interfaces crucial for high-quality van der Waals heterostructures.

Contribution

It presents a novel polymer-based transfer method with lens shapes that enables precise, bubble-free stacking of 2D materials for improved device quality.

Findings

Achieved bubble-free 2D material assembly

Controlled transfer interface with unidirectional sweep

Enhanced interface cleanliness for heterostructure devices

Abstract

The key to achieving high-quality van der Waals heterostructure devices made by stacking two-dimensional (2D) layered materials lies in having a clean interface without interfacial bubbles and wrinkles. In this study, the pinpoint pick-up and transfer system of 2D crystals is constructed using polymers with lens shapes. We report the bubble-free and clean-interface assembly of 2D crystals in which unidirectional sweep of the transfer interface precisely controlled with the help of the inclined substrate pushes the bubbles away from the interface.