Journal article
High-Frequency Sheet Conductance of Nanolayered WS2 Crystals for Two-Dimensional Nanodevices
ACS applied nano materials, Vol.5(10), pp.15557-15562
10/28/2022
DOI: 10.1021/acsanm.2c03517
PMCID: PMC9623546
PMID: 36338326
Abstract
Time-resolved terahertz (THz) spectroscopy is a powerful technique for the determination of charge transport properties in photoexcited semiconductors. However, the relatively long wavelengths of THz radiation and the diffraction limit imposed by optical imaging systems reduce the applicability of THz spectroscopy to large samples with dimensions in the millimeter to centimeter range. Exploiting THz near-field spectroscopy, we present the first time-resolved THz measurements on a single exfoliated 2D nanolayered crystal of a transition metal dichalcogenide (WS2). The high spatial resolution of THz near-field spectroscopy enables mapping of the sheet conductance for an increasing number of atomic layers. The single-crystalline structure of the nanolayered crystal allows for the direct observation of low-energy phonon modes, which are present in all thicknesses, coupling with free carriers. Density functional theory calculations show that the phonon mode corresponds to the breathing mode between atomic layers in the weakly bonded van der Waals layers, which can be strongly influenced by substrate-induced strain. The non-invasive and high-resolution mapping technique of carrier dynamics in nanolayered crystals by time-resolved THz time domain spectroscopy enables possibilities for the investigation of the relation between phonons and charge transport in nanoscale semiconductors for applications in two-dimensional nanodevices.
Details
- Title: Subtitle
- High-Frequency Sheet Conductance of Nanolayered WS2 Crystals for Two-Dimensional Nanodevices
- Creators
- Stan E.T. ter Huurne - Department of Applied Physics and Eindhoven Hendrik Casimir InstituteAdonai Rodrigues Da Cruz - Eindhoven University of TechnologyNiels van Hoof - Eindhoven University of TechnologyRasmus H. Godiksen - Eindhoven University of TechnologySara A. Elrafei - Eindhoven University of TechnologyAlberto G. Curto - Eindhoven University of TechnologyMichael E. Flatté - Eindhoven University of TechnologyJaime Gómez Rivas - Eindhoven University of Technology
- Resource Type
- Journal article
- Publication Details
- ACS applied nano materials, Vol.5(10), pp.15557-15562
- DOI
- 10.1021/acsanm.2c03517
- PMID
- 36338326
- PMCID
- PMC9623546
- NLM abbreviation
- ACS Appl Nano Mater
- ISSN
- 2574-0970
- eISSN
- 2574-0970
- Publisher
- American Chemical Society
- Grant note
- DOI: 10.13039/100006151, name: Basic Energy Sciences, award: DE-SC0021314; DOI: 10.13039/100010665, name: H2020 Marie Sklodowska-Curie Actions, award: 721394; DOI: 10.13039/501100003246, name: Nederlandse Organisatie voor Wetenschappelijk Onderzoek, award: 740.018.009, Vici 680-47-628
- Language
- English
- Date published
- 10/28/2022
- Academic Unit
- Electrical and Computer Engineering; Physics and Astronomy
- Record Identifier
- 9984429028002771