Atomistic Origin of Photoluminescence Quenching in Colloidal MoS2and WS2Nanoplatelets

Verfasst von

Surender Kumar, Markus Fröhlich, Stefan Velja, Marco Kögel, Onno Strolka, André Niebur, Samuell Ginzburg, Muhammad Sufyan Ramzan, Jannik C. Meyer, Jannika Lauth, Caterina Cocchi

Abstract

Large chemical tunability and strong light–matter interactions make colloidal transition metal dichalcogenide (TMD) nanostructures particularly suitable for light-emitting applications. However, ultrafast exciton decay and quenched photoluminescence (PL) 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. These intrinsic trap states stem from the metal d-orbitals and persist even when the sulfur-terminated edges are hydrogen-passivated. Notably, WS2 nanostructures 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 the catalytic activity. Our work represents an important step forward in understanding exciton quenching in TMD nanoplatelets and stimulates additional research to refine physicochemical protocols for enhanced PL.

Details

Organisationseinheit(en)
PhoenixD: Simulation, Fabrikation und Anwendung optischer Systeme
Externe Organisation(en)
Friedrich-Schiller-Universität Jena
Eberhard Karls Universität Tübingen
University of Cambridge
Typ
Artikel
Journal
Nano letters
Band
26
Seiten
3064-3072
Anzahl der Seiten
9
ISSN
1530-6984
Publikationsdatum
11.03.2026
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Bioengineering, Allgemeine Chemie, Allgemeine Materialwissenschaften, Physik der kondensierten Materie, Maschinenbau
Elektronische Version(en)
https://doi.org/10.1021/acs.nanolett.5c05893 (Zugang: Offen )