Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, CA, 94305, USA.
Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
Angew Chem Int Ed Engl. 2020 Nov 23;59(48):21603-21612. doi: 10.1002/anie.202007683. Epub 2020 Sep 23.
Upconverting nanoparticles (UCNPs) are promising candidates for photon-driven reactions, including light-triggered drug delivery, photodynamic therapy, and photocatalysis. Herein, we investigate the NIR-to-UV/visible emission of sub-15 nm alkaline-earth rare-earth fluoride UCNPs (M Ln F MLnF) with a CaF shell. We synthesize 8 alkaline-earth host materials doped with Yb and Tm , with alkaline-earth (M) spanning Ca, Sr, and Ba, MgSr, CaSr, CaBa, SrBa, and CaSrBa. We explore UCNP composition, size, and lanthanide doping-dependent emission, focusing on upconversion quantum yield (UCQY) and UV emission. UCQY values of 2.46 % at 250 W cm are achieved with 14.5 nm SrLuF@CaF particles, with 7.3 % of total emission in the UV. In 10.9 nm SrYbF:1 %Tm @CaF particles, UV emission increased to 9.9 % with UCQY at 1.14 %. We demonstrate dye degradation under NIR illumination using SrYbF:1 %Tm @CaF , highlighting the efficiency of these UCNPs and their ability to trigger photoprocesses.
上转换纳米粒子（UCNPs）是光子驱动反应的有前途的候选者，包括光触发药物输送、光动力疗法和光催化。在此，我们研究了具有 CaF 壳的亚 15nm 碱土族稀土氟化物 UCNPs（M Ln F MLnF）的近红外到紫外/可见发射。我们合成了 8 种掺杂 Yb 和 Tm 的碱土宿主材料，碱土（M）跨越 Ca、Sr 和 Ba、MgSr、CaSr、CaBa、SrBa 和 CaSrBa。我们探索了 UCNP 的组成、尺寸和镧系掺杂依赖性发射，重点是上转换量子产率（UCQY）和紫外发射。在 14.5nm 的 SrLuF@CaF 颗粒中实现了 250Wcm 的 2.46%的 UCQY 值，其中 7.3%的总发射在紫外区。在 10.9nm 的 SrYbF:1%Tm@CaF 颗粒中，UV 发射增加到 9.9%，UCQY 为 1.14%。我们使用 SrYbF:1%Tm@CaF 证明了在近红外光照射下染料的降解，突出了这些 UCNPs 的效率及其触发光过程的能力。
