Dresden 2026 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 26: French-German Session: 2D Materials, Thin Films and Interfaces II

CPP 26.2: Vortrag

Dienstag, 10. März 2026, 14:30–14:45, HÜL/S386

Atomistic Origin of Photoluminescence Quenching in Colloidal MoS₂ and WS₂ Nanoplatelets — •Surender Kumar¹, Markus Fröhlich², Stefan Velja¹, Marco Kögel², Onno Strolka^2,3, André Niebur³, Samuell Ginzburg⁴, Muhammad Sufyan Ramzan¹, Jannik C. Meyer², Jannika Lauth^2,3, and Caterina Cocchi¹ — ¹Friedrich-Schiller-Universität Jena, Germany — ²Eberhard Karls University of Tübingen, Germany — ³Leibniz University of Hannover, Germany — ⁴University of Cambridge, UK

Large chemical tunability and strong light-matter interactions make colloidal transition metal dichalcogenide nanostructures particularly suitable for light-emitting applications. However, ultrafast exciton decay and quenched photoluminescence limit their potential. Combining femtosecond transient absorption spectroscopy with first-principles calculations on MoS₂ and WS₂ nanoplatelets, we reveal that the observed sub-picosecond exciton decay originates from edge-located optically bright hole traps [1]. These intrinsic trap states stem from the metal d-orbitals and persist even when the sulfur-terminated edges are hydrogen-passivated. Notably, WS₂ nanoplatelets show more localized and optically active edge states than their MoS₂ counterparts, and zigzag edges exhibit a higher trap density than armchair edges. The nanoplatelet size dictates the competition between ultrafast edge-trapping and slower core-exciton recombination, and the states responsible for exciton quenching enhance catalytic activity.
[1] S. Kumar, et al., arXiv:2511.19077 (2025)

Keywords: Transient absorption spectroscopy; Photoluminescence quenching; DFT; Edge states; Colloidal MoS2 and WS2 nanoplatelet