Understanding the impact of heavy ions and tailoring the optical properties of large-area monolayer WS₂ using focused ion beam

This work investigates the lateral damage in large-area monolayer WS₂ caused by gallium focused ion beam (FIB) milling. Three distinct zones (near, dark, and far-out) away from the milling location were identified and characterized using photoluminescence (PL) and Raman spectroscopy. The study reveals an unexpected bright ring-shaped emission around the milled area and shows that while some localized damage is inevitable, distant destruction can be eliminated by reducing the ion beam current. The findings open avenues for tailoring TMDC optical properties via charge and defect engineering using FIB lithography.

Fahrettin Sarcan, Nicola J. Fairbairn, Panaiot Zotev, Toby Severs-Millard, Daniel J. Gillard, Xiaochen Wang, Ben Conran, Michael Heuken, Ayşe Erol, Alexander I. Tartakovskii, Thomas F. Krauss, Gordon J. Hedley, Yue Wang