Department of Chemistry, Renmin University of China, Beijing 100872, China.
Phys Chem Chem Phys. 2018 Jun 27;20(25):17141-17147. doi: 10.1039/c8cp02142b.
Research on the energy transfer mechanism of rare-earth-doped upconversion nanoparticles (UCNPs) has been an important area due to the increasing demand for tuning multicolor emission and enhancing the upconversion efficiency; however, because of large energy mismatch, many lanthanide activators, such as Eu3+, cannot realize highly efficient near infrared-to-visible upconversion by simple codoping of Yb3+. Therefore, introduction of other ions to assist the energy transfer process is required. Herein, we prepared core-shell nanoparticles with different doping locations to investigate the upconversion energy transfer mechanism. The upconversion luminescence (UCL) of core-shell nanoparticles was investigated by steady-state luminescence and time-resolved luminescence spectra. The UCL behaviors in these different multi-activator core-shell nanoparticles were observed. The results revealed different energy transfer channels influenced by the doping location of activators. This study may open up new avenues of structure design for fine-tuning of multicolor UCL for specific applications.
研究稀土掺杂上转换纳米粒子（UCNPs）的能量转移机制一直是一个重要领域，因为人们对调谐多色发射和提高上转换效率的需求不断增加；然而，由于能量失配较大，许多镧系激活剂，如 Eu3+，不能通过简单地共掺杂 Yb3+实现高效的近红外-可见上转换。因此，需要引入其他离子来辅助能量转移过程。在此，我们制备了具有不同掺杂位置的核壳纳米粒子，以研究上转换能量转移机制。通过稳态发光和时间分辨发光光谱研究了核壳纳米粒子的上转换发光（UCL）。观察到了这些不同多活性剂核壳纳米粒子中的 UCL 行为。结果表明，不同的能量转移通道受活性剂掺杂位置的影响。这项研究可能为特定应用的多色 UCL 的精细调控开辟新的结构设计途径。
