Solving the Synthetic Riddle of Colloidal Two-Dimensional PbTe Nanoplatelets with Tunable Near-Infrared Emission

authored by

Leon Biesterfeld, Mattis T. Vochezer, Marco Kögel, Ivan A. Zaluzhnyy, Marina Rosebrock, Lars F. Klepzig, Wolfgang Leis, Michael Seitz, Jannik C. Meyer, Jannika Lauth

Abstract

Near-infrared emitting colloidal two-dimensional (2D) PbX (X = S, Se) nanoplatelets (NPLs) have emerged as interesting materials with strong size quantization in the thickness dimension. They act as model systems for efficient charge carrier multiplication and hold potential as intriguing candidates for fiber-based photonic quantum applications. However, synthetic access to the third family member, 2D PbTe, remains elusive due to challenging precursor chemistry. Here, we report a direct synthesis for 2D PbTe NPLs with tunable photoluminescence [PL, 910-1460 nm (1.36-0.85 eV), PL quantum yields 1-15%], based on aminophosphine precursor chemistry. Ex situ transamination of tris(dimethylamino)phosphine telluride with octylamine is confirmed by ³¹P nuclear magnetic resonance and yields a reactive tellurium precursor for the formation of 2D PbTe NPLs at temperatures as low as 0 °C. The PL position of the PbTe NPLs is tunable by controlling the Pb/Te ratio in the reaction. Grazing-incidence wide-angle X-ray scattering confirms the 2D geometry of the NPLs and the formation of superlattices. The importance of a postsynthetic passivation of PbTe NPLs by PbI₂ to ensure colloidal stability of the otherwise oxygen-sensitive samples is supported by X-ray photoelectron spectroscopy. Our results expand and complete the row of lead chalcogenide-based 2D NPLs, opening up new ways for further pushing the optical properties of 2D NPLs into the infrared and toward technologically relevant wavelengths.

Organisation(s)

PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines
Institute of Physical Chemistry and Electrochemistry

External Organisation(s)

University of Tübingen

Type

Article

Journal

Chemistry of materials

Volume

36

Pages

7197-7206

No. of pages

10

ISSN

0897-4756

Publication date

13.08.2024

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Chemistry(all), Chemical Engineering(all), Materials Chemistry

Electronic version(s)

https://doi.org/10.1021/acs.chemmater.4c00939 (Access: Closed)