Room‐Temperature Tuning of Electrical Conductivity in Single MoS₂ Flakes via Nanoscale Amorphization by Focused Ion Beam

Abstract High spatially resolved defect engineering via local amorphization enables controlled processing of materials with enhanced electrical properties and catalytic sites, offering prospects for electronics and hydrogen evolution applications. The intriguing electrical properties of amorphous Molybdenum Disulfide (MoS 2 ) open opportunities for electrical and electrochemical devices. However, controlling electrical features in miniaturized devices with minimal carbon contamination under mild conditions remains challenging. Here, the obtention of ultra‐large MoS 2 monolayers is reported, and fine‐tune defect insertion in a single flake using focused ion beam at room temperature. By controlling defect density on electrochemically thinned samples, electrical conductivity increases by one order of magnitude. The width of the conductive amorphous channels can be tuned in a dose‐dependent fashion down to ≈700 nm. Defect types, including amorphized areas, are identified by high‐resolution transmission electron microscopy. Finally, insights into the origin of the higher conductivity in amorphous MoS 2 are obtained using density functional theory and ab initio molecular dynamics simulations on structures with varying stoichiometry and vacancy types. These findings enable precise tuning of electrical properties under mild conditions using high‐aspect ratio pristine MoS 2 layers.