Electronic Structure of Colloidal 2H-MoS₂ Mono and Bilayers Determined by Spectroelectrochemistry

verfasst von

Kai M. Wurst, Onno Strolka, Jonas Hiller, Jakob Keck, Alfred J. Meixner, Jannika Lauth, Marcus Scheele

Abstract

The electronic structure of mono and bilayers of colloidal 2H-MoS₂ nanosheets synthesized by wet-chemistry using potential-modulated absorption spectroscopy (EMAS), differential pulse voltammetry, and electrochemical gating measurements is investigated. The energetic positions of the conduction and valence band edges of the direct and indirect bandgap are reported and observe strong bandgap renormalization effects, charge screening of the exciton, as well as intrinsic n-doping of the as-synthesized material. Two distinct transitions in the spectral regime associated with the C exciton are found, which overlap into a broad signal upon filling the conduction band. In contrast to oxidation, the reduction of the nanosheets is largely reversible, enabling potential applications for reductive electrocatalysis. This work demonstrates that EMAS is a highly sensitive tool for determining the electronic structure of thin films with a few nanometer thicknesses and that colloidal chemistry affords high-quality transition metal dichalcogenide nanosheets with an electronic structure comparable to that of exfoliated samples.

Organisationseinheit(en)

PhoenixD: Simulation, Fabrikation und Anwendung optischer Systeme
Laboratorium für Nano- und Quantenengineering

Externe Organisation(en)

Eberhard Karls Universität Tübingen

Typ

Artikel

Journal

SMALL

Band

19

ISSN

1613-6810

Publikationsdatum

07.06.2023

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Biotechnologie, Chemie (insg.), Biomaterialien, Werkstoffwissenschaften (insg.)

Elektronische Version(en)

https://doi.org/10.1002/smll.202207101 (Zugang: Offen)