Thermally induced multicolor emissions of upconversion hybrids with large color shifts for anticounterfeiting applications
| Autor: | Yanqing Hu, Qiyue Shao, Xinyi Deng, Jianqing Jiang, Dongdong Song, Yan Dong, Shouyu Han |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
business.industry Upconversion luminescence 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Photon upconversion 0104 chemical sciences Nanocrystal Color changes Materials Chemistry Optoelectronics Spectral analysis Irradiation 0210 nano-technology business Thermal quenching Power density |
| Zdroj: | Journal of Materials Chemistry C. 7:11770-11775 |
| ISSN: | 2050-7534 2050-7526 |
| Popis: | Upconversion materials with tunable emission colors are highly desired for novel anticounterfeiting strategies because they offer additional security features. Herein, we report a series of upconversion hybrids consisting of NaYF4:Yb/Ln microrods (MRs) and NaGdF4:Yb/Ln@NaYbF4 (Ln = Er, Ce/Ho, Tm) core/active-shell nanocrystals (NCs). A normal thermal quenching of upconversion luminescence (UCL) is found for the MRs, but a thermal UCL enhancement occurs for the small-sized NCs. Consequently, the hybrids exhibit temperature-responsive multicolor emissions with large color shifts. The UCL enhancement mechanism is further revealed by temperature-dependent steady/transient spectral analysis in various atmospheres. Moreover, various color-shifting pathways are realized by adjusting the MR/NC combinations in the hybrids. Thanks to the effective photothermal conversion of core/active-shell NCs, color changes of the printed patterns by the hybrid ink are achieved simply by single-laser irradiation at a relatively low power density. These desirable properties make the designed hybrids promising for anticounterfeiting applications with advantages of high-level security and convenient authentication methods. |
| Databáze: | OpenAIRE |
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