APL Materials (Jul 2023)

Excitation wavelength dependent triple-mode photoluminescence of copper-based halides for advanced anti-counterfeiting

  • Chengjun Liu,
  • Yuyi Zhang,
  • Manman Luo,
  • Lixi Wang,
  • Xingyu Liu,
  • Jiangyong Pan,
  • Zihan Zhao,
  • Fan Fang,
  • Lei Mao,
  • Yuling Huang,
  • Bingqi Wang,
  • Congyuan Lin,
  • Wei Lei,
  • Qing Li,
  • Zhiwei Zhao,
  • Jun Wu,
  • Zhuoya Zhu,
  • Mehmet Ertugrul,
  • Xiaobing Zhang,
  • Jing Chen,
  • Dewei Zhao

DOI
https://doi.org/10.1063/5.0152479
Journal volume & issue
Vol. 11, no. 7
pp. 071109 – 071109-9

Abstract

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New fluorescent materials with a low cost, hypotoxicity, and concealment are desired for the application of anti-counterfeiting. Herein, we report a CsCu2I3@Cs3Cu2I5 composite with a triple-mode photoluminescence (PL) feature by simply adjusting the excitation wavelengths, which are ascribed to the multiple excited states of different phases in the CsCu2I3@Cs3Cu2I5 composite. The broadband emission and high quantum yield (∼51%) of the composite originate from the structure-oriented self-trapped excitons effect of Cs3Cu2I5 and CsCu2I3 phases. Moreover, the incorporation of polyethylene oxide (PEO) into this composite improves the stability of CsCu2I3@Cs3Cu2I5@PEO against harsh environments. The CsCu2I3@Cs3Cu2I5@PEO composite has a slight decay of ∼5% of its initial PL intensity and only a 3.5% shift of the corresponding color coordinate after 30 days of storage. More importantly, its initial PL intensity shows only 10.3% decay under ultraviolet exposure for 200 h. Our work provides a promising approach to design materials for advanced anti-counterfeiting applications.