Photoexcitation of PbS nanosheets leads to highly mobile charge carriers and stable excitons

verfasst von

Jannika Lauth, Michele Failla, Eugen Klein, Christian Klinke, Sachin Kinge, Laurens D.A. Siebbeles

Abstract

Solution-processable two-dimensional (2D) semiconductors with chemically tunable thickness and associated tunable band gaps are highly promising materials for ultrathin optoelectronics. Here, the properties of free charge carriers and excitons in 2D PbS nanosheets of different thickness are investigated by means of optical pump-terahertz probe spectroscopy. By analyzing the frequency-dependent THz response, a large quantum yield of excitons is found. The scattering time of free charge carriers increases with nanosheet thickness, which is ascribed to reduced effects of surface defects and ligands in thicker nanosheets. The data discussed provide values for the DC mobility in the range 550-1000 cm² V^-1 s^-1 for PbS nanosheets with thicknesses ranging from 4 to 16 nm. Results underpin the suitability of colloidal 2D PbS nanosheets for optoelectronic applications.

Organisationseinheit(en)

Institut für Physikalische Chemie und Elektrochemie
PhoenixD: Simulation, Fabrikation und Anwendung optischer Systeme

Externe Organisation(en)

Delft University of Technology
Universität Hamburg
Swansea University
Universität Rostock
Toyota Motor Europe

Typ

Artikel

Journal

NANOSCALE

Band

11

Seiten

21569-21576

Anzahl der Seiten

8

ISSN

2040-3364

Publikationsdatum

28.11.2019

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Werkstoffwissenschaften (insg.)

Elektronische Version(en)

https://doi.org/10.48550/arXiv.1908.04711 (Zugang: Offen)
https://doi.org/10.1039/c9nr07927k (Zugang: Geschlossen)
https://doi.org/10.15488/10413 (Zugang: Offen)