Enhanced red upconversion emission and its mechanism in Yb3+–Er3+ codoped α-NaLuF4 nanoparticles
| Autor: | Yueli Zhang, Zhiren Qiu, Hao Lin, Anming Li, Shenghong Yang, Dekang Xu |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Chemistry
Analytical chemistry Nanoparticle Nanotechnology 02 engineering and technology General Chemistry Rate equation 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Catalysis Hydrothermal circulation Photon upconversion 0104 chemical sciences Materials Chemistry 0210 nano-technology Luminescence |
| Zdroj: | New Journal of Chemistry. 41:1193-1201 |
| ISSN: | 1369-9261 1144-0546 |
| Popis: | A series of Yb3+–Er3+ codoped α-NaLuF4 nanoparticles were prepared via a hydrothermal process. Enhanced red upconversion (UC) luminescence can be achieved by adjusting the initial solution pH, and the intensity of red emission (660 nm) is enhanced 23 times. By establishing rate equations, a theoretical model about the red UC mechanism is presented. It is proposed that the highly efficient red UC emission is mainly due to the UC process from the saturated 4I13/2 (Er3+) state, which is induced by the effective energy-back-transfer process (primary): 4S3/2 (Er3+) + 2F7/2 (Yb3+) → 4I13/2 (Er3+) + 2F5/2 (Yb3+) and the cross-relaxation effect among Er3+ (minor): 4S3/2 + 4I15/2 → 4I9/2 + 4I13/2 at a high pH value of the initial solution. Moreover, the influence of solution pH on the red UC luminescence is systematically studied under different hydrothermal conditions. This paper provides an effective route to obtain nanoparticles with bright red UC luminescence, which may be suitable for biological imaging and display devices. |
| Databáze: | OpenAIRE |
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