Large-Area Mechanically-Exfoliated Two-Dimensional Materials on Arbitrary Substrates

Abstract

Atomically-thin crystals have been shown to be rich in fundamental phenomena and are promising for various applications. Mechanical exfoliation of (2D) materials from bulk crystals is particularly suited for fundamental studies due to the high quality of the resulting monolayer crystals. To date, several techniques have been developed to increase the exfoliation yield, however, they still suffer drawbacks. In this work, a novel method that exploits gold-assisted exfoliation to prepare large-area monolayers of various layered materials followed by their transfer to arbitrary substrates is introduced. X-ray photoelectron, Raman, and photoluminescence spectroscopies are employed to assess the quality of the prepared layers and their optical properties. Then, field-effect transistors and photodetectors are fabricated to demonstrate the suitability of this technique for large-area optoelectronic devices.