Browse by author
Lookup NU author(s): Professor Thomas PenfoldORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
CuInS2 quantum dots (QDs) have gained significant attention owing to their remarkable broadband emission, making them desirable for various optoelectronic applications requiring efficient luminescent nanomaterials. However, maximizing radiative recombination in CuInS2 QDs necessitates minimizing intragap trap states. A common approach involves the introduction of Zn during the synthesis, which typically promotes the formation of a ZnS shell that passivates the QD surface. Despite its importance, the characterization and quantification of Zn incorporation using conventional techniques, such as optical spectroscopy or electron microscopy, remains challenging. In this study, we utilized X-ray absorption spectroscopy, in both X-ray absorption near-edge structure and extended X-ray absorption fine structure spectral ranges, to investigate Zn incorporation into CuInS2 QDs, probing at the Zn, S, and Cu K-edges. This approach allowed us to detect the formation of a ZnS surface shell, tentatively quantifying its thickness, and to distinguish between Zn as a substituent at the shell or as an interstitial defect. Additionally, we explored the dynamical properties of CuInS2 QDs using time-resolved optical spectroscopies, particularly in the presence of electron and hole acceptors (benzoquinone and phenothiazine), observing that hole transfer is highly sensitive to shell thickness. These results provide deeper insights into the Zn-induced shell.
Author(s): Burgos-Caminal A, Vale BRC, Fonseca AFV, Hidalgo JF, Collet EPP, García L, Vega-Mayoral V, Garcia-Orrit S, Arnay I, Cabanillas-González J, Simonelli L, Nogueira AF, Schiavon MA, Penfold TJ, Padilha LA, Gawelda W
Publication type: Article
Publication status: Published
Journal: Chemistry of Materials
Year: 2026
Pages: epub ahead of print
Online publication date: 09/03/2026
Acceptance date: 25/02/2026
Date deposited: 18/03/2026
ISSN (print): 0897-4756
ISSN (electronic): 1520-5002
Publisher: American Chemical Society
URL: https://doi.org/10.1021/acs.chemmater.5c01878
DOI: 10.1021/acs.chemmater.5c01878
Data Access Statement: The data that support the findings in this study are openly available at the IMDEA Nanoscience repository ref 62.
Altmetrics provided by Altmetric
