Thermally Activated Gold-Mediated Transition Metal Dichalcogenide Exfoliation and a Unique Gold-Mediated Transfer

Layered materials like transition metal dichalcogenides (TMDCs) enable exciting new physics in their 2D limit. Combined with successful demonstrations of 2D transistors and devices, the need for high-quality large-scale monolayers increases. In this light, scalable gold-mediated exfoliations attract broad attention to supersede the traditional scotch tape method as a means for high-quality materials. Gold proved to be suitably adhesive for the exfoliation of several 2D materials, including TMDCs. Previously reported methods rely on a simple press and peel mechanism. However, herein, a gold-mediated exfoliation enabled by low-temperature annealing is presented for the first time. This simple modification potentially increases the range of external conditions under which gold-mediated exfoliations operate in a robust manner. The exfoliation achieves scaling with parent crystal areas, rendering it on par with previously reported methods. On top of that, a unique gold-mediated transfer concept is introduced, where gold is repurposed as a metallic (polymer-free) transfer membrane. The transfer allows the deterministic and clean relocation of the exfoliated monolayers onto technologically relevant substrates like SiO2/Si. The process is benchmarked using MoS(2)as the prototypical TMDC and monolayer areas up to approximate to 80 mm(2)are successfully exfoliated and transferred.