The investigation of the properties of two-dimensional (2D) materials - materials that are one atomic layer thick - has revealed truly remarkable behavior that, in principle, enable the development of the next generation of electronic and optical devices. For example, the flexibility, strength and opto-electronic properties of some 2D materials make them ideal candidates for applications in flexible electronics (e.g. displays). However, the technological impact of these materials has not been fully realized because these devices cannot be manufactured at scale. Moreover, the steps used to create 2D electronic materials-based devices in the laboratory are inefficient and unreliable, and result in a very low yield of working devices. This Scalable NanoManufacturing (SNM) award is aimed at developing an economical, scalable, high-yield approach to the production of opto-electronic devices based on 2D electronic materials. This highly interdisciplinary research relies on several science and engineering disciplines including nanomanufacturing, electrical engineering, materials science and computation to develop and optimize the manufacturing process. The research will immerse a number of young scholars diverse in both background and experience within a highly collaborative and interdisciplinary research environment.
The laboratory process for creating devices from 2D electronic materials employs "sticky tape" as a means for exfoliating single layered samples from bulk crystals and transferring them to other substrates. Typically, the first exfoliated layer consists of multiple 2D layers of the desired material requiring repeated sticky tape exfoliation to produce a single monolayer of the material. This painstaking process is not scalable and often yields a sample too small to enable the manufacturing of devices. Recently, the research team has discovered that thin metallic films covalently or semi-covalently bonded to the surface layer of a crystal can be used as an improved sticky tape. The properties of the thin films enable isolation of monolayer samples up to 0.5 mm in lateral dimensions during the first exfoliation step. This discovery opens the door to development of a scalable nanomanufacturing approach to the fabrication of devices built from 2D electronic materials. Using a combination of theory and experiment, this award will determine the choice of metal films for exfoliation of prototypical 2D materials. Using these films, the project will develop a highly multiplexed elastomer stamping approach to automate the exfoliation process and to demonstrate the scalable fabrication of 2D electronic materials-based devices for applications ranging from opto-electronic devices to chemical sensors, and as compliant substrates for the epitaxial growth of other materials.
