Wafer-Scale Roll-Printing Process for van der Waals Multilayer-Based Optoelectronics

A weak van der Waals (vdW) force in layered materials enables their isolation into thin flakes through mechanical exfoliation while sustaining their intrinsic electronic and optical properties. Significant progress has been made in the use of chemical vapor deposition for large-area synthesis of mono- to few-layer films. Recently, multilayers of certain vdW materials, such as black phosphorus and InSe, have garnered considerable interest with their distinctive optoelectronic, electrical and/or thermal properties at the “bulk” thicknesses. These multilayer vdW materials are promising for applications such as mid-infrared to visible light emitters and detectors, batteries, electromagnetic shielding, and catalysis. In this regard, the development of a scalable and generic fabrication process that is compatible with different substrates, including those with low thermal budget, is of profound interest.
In this talk, we introduce a universal roll-printing method capable of producing vdW multilayer films on wafer-to-meter scale. This process uses sequential exfoliation and transfer of layered materials from the powder sources to target substrates through a repeated rolling of a cylindrical metal drum. We achieve uniformly coated films with a library of vdW powders on various mechanically rigid and flexible substrates. The printed films are configured into different devices including light-emitting diodes and photodetectors. The presented technique offers substantial benefits in terms of cost efficiency and a low thermal budget while offering high material quality.