Dresden 2026 – scientific programme

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DS: Fachverband Dünne Schichten

DS 12: 2D Materials I

DS 12.3: Talk

Wednesday, March 11, 2026, 10:00–10:15, REC/C213

Spatially Controlled Photoelectrochemical Thinning of 2D Transition Metal Dichalcogenides — •Simon Wörle¹, Lukas Wolz¹, Sergej Levashov¹, Franz Gröbmeyer², Johanna Eichhorn¹, Emiliano Cortes², Jeremy Robinson³, and Ian Sharp¹ — ¹Technical University of Munich — ²Ludwig Maximilian University of Munich — ³U.S. Naval Research Laboratory

The integration of two-dimensional transition metal dichalcogenides (TMDs) into functional devices and catalytic systems requires detailed understanding and control of their behavior in reactive environments. Here, we systematically investigate the photoelectrochemical (PEC) stabilities of MoS₂, WS₂, MoSe₂, and WSe₂ mono- and multilayer flakes under dark and illuminated conditions, revealing two distinct oxidation mechanisms. In the dark, anodic potentials promote oxidation at defect-rich TMD edge sites, with subsequent dissolution of the oxidized species causing progressive lateral shrinkage, while the basal planes remain stable. Under white light illumination from a solar simulator, photoexcited holes drive electrochemical thinning of TMD multilayer flakes, which proceeds at anodic potentials lower than those required for lateral edge oxidation in the dark. This PEC-driven thinning enables controllable top-down fabrication of large-area TMD films with well-defined thicknesses. Importantly, the use of a focused laser beam rather than white light illumination enables precise spatial control over the PEC oxidation process, allowing localized patterning and thinning in predefined regions for the processing and integration of 2D materials into functional devices.

Keywords: transition metal dichalcogenides; photoelectrochemical; oxidation; thinning; 2D materials