Assembly of High-Performance van der Waals Devices Using Commercial Polyvinyl Chloride Films

TL;DR

This paper introduces a durable, reusable PVC film-based stamp for assembling 2D material heterostructures, simplifying fabrication, reducing contamination, and enabling complex device architectures with high performance.

Contribution

The authors develop a novel PVC film stamp method that improves reusability, simplifies assembly, and broadens applicability for high-quality 2D heterostructure fabrication.

Findings

PVC stamps withstand multiple transfer cycles.

High-quality graphene/hBN heterostructures with excellent electrical performance.

Successful integration of nanostructured films like AlGaAs.

Abstract

Control over the position, orientation, and stacking order of two-dimensional (2D) materials within van der Waals heterostructures is crucial for applications in electronics, spintronics, optics, and sensing. The most popular strategy for assembling 2D materials uses purpose-built stamps with working surfaces made from one of several different polymers. However, these stamps typically require tedious preparation steps and suffer from poor durability, contamination, and limited applicability to specific 2D materials or surfaces. Here, we demonstrate significant improvements upon current 2D flake transfer and assembly practices by using mechanically durable stamps made from polyvinyl chloride (PVC) thin films. These stamps are simpler to prepare compared with existing methods and can withstand multiple transfer cycles, enabling greater reusability. We use two commercially available PVC films with distinct pick-up and release temperatures. Together, these films also enable polymer-to-polymer flake transfers and stack-and-flip fabrication of inverted heterostructures in one seamless process. Systematic comparisons of cleaning processes confirm the removal of PVC-derived residue from the assembled structures to create atomically clean interfaces. We demonstrate the utility and versatility of these polymer films and transfer process by fabricating graphene/hexagonal boron nitride heterostructure devices with high-performance electrical characteristics. Further, we demonstrate the ability to pick up and to deposit bulk aluminum gallium arsenide nanostructured films, enabling the creation of heterogeneously integrated devices. This technique increases fabrication rates, improves device quality, and enables more complex structures, thereby facilitating nanomaterial assembly in a broad range of applications.