Shedding Light on Host-to-Yb<SUP>3+</SUP> Energy Transfer in Cs<sub>2</sub>AgBiBr<sub>6</sub>:Yb<SUP>3+</SUP> (nano)crystals

JW de Wit, LL Sonneveld, A Meijerink*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

The optical properties of Cs2AgBiBr6 double perovskite nanocrystals have attracted considerable attention as lead-free alternatives to lead halide perovskites. A promising strategy to create additional flexibility in the emission color is doping lanthanide ions into Cs2AgBiBr6. Incorporating Yb3+ in the lattice has been shown to give rise to near-infrared (NIR) emission, but the energy transfer mechanism remained unclear. Here, we report on the luminescence and sensitization mechanism of Yb3+ in Cs2AgBiBr6 nano- and microcrystals. We observe that the incorporation of Yb3+ in the host lattice does not strongly affect the broadband red emission of the Cs2AgBiBr6 host but does give rise to an additional and characteristic ∼1000 nm NIR line emission from Yb3+. Temperature-dependent and time-resolved photoluminescence studies of undoped and Yb-doped Cs2AgBiBr6 reveal that the energy transfer does not take place through the red emissive state of the Cs2AgBiBr6 host. Instead, there is a competition between relaxation to the red-emitting state and trapping of the photoexcited charge carriers on Yb3+. Trapping on Yb3+ subsequently results in a charge transfer state that relaxes to the 2F5/2 excited state of Yb3+, followed by NIR narrow line f–f emission to the 2F7/2 ground state.
Original languageEnglish
Pages (from-to)2857-2866
Number of pages10
JournalChemistry of Materials
Volume36
Issue number6
DOIs
Publication statusPublished - 4 Mar 2024

Bibliographical note

Publisher Copyright:
© 2024 The Authors. Published by American Chemical Society.

Funding

J.W. and A.M. acknowledge financial support for the project. CHEMIE.PGT.2019.004 of TKI/Topsector Chemie, which is partly financed by The Netherlands Organisation for Scientific Research (NWO).

FundersFunder number
Nederlandse Organisatie voor Wetenschappelijk Onderzoek

    Fingerprint

    Dive into the research topics of 'Shedding Light on Host-to-Yb<SUP>3+</SUP> Energy Transfer in Cs<sub>2</sub>AgBiBr<sub>6</sub>:Yb<SUP>3+</SUP> (nano)crystals'. Together they form a unique fingerprint.

    Cite this