Mn4+-Doped Fluoride Nanocrystals Enable High-Resolution Red-Emitting X-ray Imaging Screens

Khursand E. Yorov, Wasim J. Mir, Xin Song, Luis Gutiérrez-Arzaluz, Rounak Naphade, Saidkhodzha Nematulloev, Cailing Chen, Ren Wu Huang, Bingyao Shao, Bashir E. Hasanov, Yu Han, Omar F. Mohammed*, Osman M. Bakr*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Mn4+-doped fluorides are a growing class of narrow-band red-emitting phosphors for lighting and display technologies. However, we lack a method for synthesizing these materials as colloidal nanocrystals (NCs), making their solution processing difficult and limiting their potential applications. Herein, we propose a colloidal approach to the preparation of Mn4+-doped inorganic hexafluoride (AxB′F6:Mn4+, in which A = K, Cs and B′ = Al, Si, Sn) NCs with narrow size distributions. Our method can be extended to different matrices and dopant compositions. Furthermore, it permits the fine-tuning of the Mn4+ concentration in the NCs. The AxB′F6:Mn4+ NCs exhibit narrow-band bright-red emission with a photoluminescence quantum yield of up to ∼73% and long-term stability, and they can form colloidal solutions in various polar and nonpolar solvents. The solution processability of the NCs and their small size enabled the fabrication of transparent and flexible NC-polymer composite films, which we were fashioned into X-ray imaging scintillators. These scintillators exhibit excellent performance with a high X-ray imaging resolution of 20 lp/mm, and a relatively low detection limit of 720 nGy/s. Our synthesis strategy makes way for the exploration of a new class of red-emitting colloidal NCs for various downconversion applications.

Original languageEnglish (US)
Pages (from-to)2273-2281
Number of pages9
JournalACS Materials Letters
Issue number11
StatePublished - Nov 7 2022

Bibliographical note

Funding Information:
The authors acknowledge the financial support provided by King Abdullah University of Science and Technology (KAUST). We also acknowledge Dr. Idoia Hita and Claudia Carraro for their help in preparing standard operating procedures for HF-involved experiments.

Publisher Copyright:
© 2022 American Chemical Society.

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Biomedical Engineering
  • Materials Science(all)


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