Atomistic Origin of Photoluminescence Quenching in Colloidal MoS2 and WS2 Nanoplatelets

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

arXiv · 2511.19077

Atomistic Origin of Photoluminescence Quenching in Colloidal MoS2 and WS2 Nanoplatelets

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

View original source ↗Read source document ↗Export metadata ↓

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 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.

Explore related subjects

cond-mat.mtrl-sci

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Surender Kumar, Markus Fröhlich, Stefan Velja, Marco Kögel, Onno Strolka, André Niebur, Samuell Ginzburg, Muhammad Sufyan Ramzan, Jannik C. Meyer, Jannika Lauth, Caterina Cocchi. 2026-02-04. Atomistic Origin of Photoluminescence Quenching in Colloidal MoS2 and WS2 Nanoplatelets. https://arxiv.org/abs/2511.19077

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Electronic States, Spin-Orbit Coupling and Magnetism in Germanium 60° Dislocations

Defects in semiconductors have recently attracted renewed interest owing to their potential in novel quantum applications. Here we investigate the electronic and magnetic properties induced by 60° dislocations in Ge. Using large-scale DFT calculations, we determine the band structure for both the shuffle and glide sets in their lowest-energy configurations. The band structure for the shuffle set reveals defect-induced dispersive bands localized within the band gap near the $Γ$ point, whereas for the glide set, we observe strong overlap with the conduction band. Defect-induced band splitting evident away from $Γ$ reveals Rashba-Dresselhaus spin-orbit coupling, an effect previously reported only for screw dislocations. Remarkably, we find evidence that specific dislocation arrangements can stabilize antiferromagnetic ordering with sizable local magnetic moments and considerable exchange splitting between opposite spin states. These results uncover rich physics in Ge dislocations through the combination of spin-orbit coupling and magnetic ordering, potentially enabling novel defect-based functionalities in Ge devices.

cond-mat.mtrl-sci↗

arXiv2026

Thermal Hall resistivity and transverse entropy production in a phonon gas

Most theories of the phonon thermal Hall effect ignore phonon-phonon interactions. Here, by recalling the Senftleben-Beenakker effect in molecular gases, we argue that a magnetic field, by influencing collisions between neutral non-chiral [quasi-]particles, can induce a Hall response. Our study of two insulators with distinct crystal structures, layered honeycomb WS$_2$ and ferroelectric perovskite LiNbO$_3$, finds that $κ_{xx}$ and $κ_{xy}$ peak at nearly the same temperature in both materials, as reported in other insulators. We show that the amplitude of transverse thermal \emph{resistivity} in clean and simple insulators is of the order of $|W_\perp/B|\simeq \frac{e}{k_B u}$, where $e$ and $k_B$ are fundamental constants and $u$ is the binding energy density of the crystal. In complex and dirty insulators, $|W_\perp/B|$ is much larger and has a significant temperature dependence. Nevertheless, the peak thermal Hall \textit{angle} in all insulators remains roughly the same.

cond-mat.mtrl-sci↗

arXiv2026

First-principles calculations of electronic structure

The emergence of high-mobility at provides a fertile platform for exploring emergent quantum phenomena and next-generation oxide electronics. Here, using first-principles density functional theory (DFT) calculations, we uncover the microscopic origin of the formed at the interface between insulators. Despite both constituents being insulating in bulk, the heterostructure develops robust metallicity at the interface, in agreement with experimental observations. This charge redistribution stabilizes at the interface. The electronic states forming enforcing carrier motion strictly within the interfacial plane. Remarkably, the spin-up parabolic band hosting the 2DEG exhibits an exceptionally small effective mass -- indicating the potential for significantly enhanced carrier mobility. Furthermore, the calculated interfacial electron density exceeds that of by nearly an order of magnitude, consistent with experimental measurement. These findings identify the heterostructure as a compelling platform for realizing and open new avenues for engineering correlated oxide interfaces for quantum electronic applications.

cond-mat.mtrl-sci↗