Nanoscience

Efficient Infrared Emission of Colloidal PbSe Nanoplatelets by Lateral Size Control

Authors

Abstract

Colloidal two-dimensional (2D) lead chalcogenide nanoplatelets (NPLs) represent highly interesting materials for near- and short wave-infrared applications including innovative glass fiber optics exhibiting negligible attenuation. In this work, we demonstrate a direct synthesis route for 2D PbSe NPLs with cubic rock salt crystal structure at low reaction temperatures of 0 °C and room temperature. A lateral size tuning of the PbSe NPLs by controlling the temper-ature and by adding small amounts of octylamine to the reaction leads to excitonic absorption features in the range of 800 – 1000 nm (1.6 – 1.3 eV) and narrow photoluminescence (PL) seamlessly covering the broadband infrared spec-tral window of 900 – 1450 nm (1.4 – 0.9 eV). The PL quantum yield of the as-synthesized PbSe NPLs is more than doubled by a postsynthetic treatment with CdCl2 (e.g. from 14.7 % to 37.4 % for NPLs emitting at 980 nm with a FWHM of 214 meV). An analysis of the slightly asymmetric PL line shape of the PbSe NPLs and their characterization by ultrafast transient absorption and time-resolved PL spectroscopy reveal a surface trap related PL contribution which is successfully reduced by the CdCl2 treatment from 40 % to 15 %. Our results open up new pathways for a direct synthesis and straightforward incorporation of colloidal PbSe NPLs as efficient infrared emitters at technologi-cally relevant telecommunication wavelengths.

Content

Thumbnail image of PbSeNPLs-Klepzig-LauthChemRxiv.pdf

Supplementary material

Thumbnail image of PbSeNPLs-Klepzig-LauthSI.pdf
Efficient Infrared Emission of Colloidal PbSe Nanoplatelets by Lateral Size Control
SI for Efficient Infrared Emission of Colloidal PbSe Nanoplatelets by Lateral Size Control

Supplementary weblinks

Lauth Group
Check out our web page at University of Hannover