[17a-M_178-1~13] 17.3 Layered materials

11:45 AM - 12:00 PM JST(2:45 AM - 3:00 AM UTC)English Presentation

[17a-M_178-11] Reversible Interface Engineering of Large-Area Gold-Exfoliated WS2

〇(PC)Matej Sebek¹, Daisuke Kiriya¹ (1.University of Tokyo)

Keywords:

Au-assisted exfoliation,transfer,photoluminescence

Gold-assisted exfoliation produces macroscopic transition metal dichalcogenide (TMD) monolayers but typically requires destructive substrate etching. Here, we elucidate the Au-WS2 interface mechanics to enable sustainable, etch-free transfer. We identify adventitious carbon as the key governor of optoelectronic properties. At room temperature, carbon acts as a dielectric spacer, preserving exciton emission but limiting adhesion. Thermal annealing forces carbon coalescence, establishing the intimate contact required for large-area yield. However, this triggers ultrafast charge transfer and screening, quenching photoluminescence and inducing positive trion (X+) emission via p-doping. Crucially, we demonstrate this coupling is reversible. Electrochemical intercalation of CTA+ ions re-introduces a molecular spacer, restoring PL and weakening adhesion to permit mechanical delamination. This yields macroscopic monolayers on arbitrary substrates without etching the gold template.