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_1−xLn_xF_2+x, MLnF) with a CaF₂ shell. We synthesize 8 alkaline‐earth host materials doped with Yb³⁺ and Tm³⁺, 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⁻² are achieved with 14.5 nm SrLuF@CaF₂ particles, with 7.3 % of total emission in the UV. In 10.9 nm SrYbF:1 %Tm³⁺@CaF₂ particles, UV emission increased to 9.9 % with UCQY at 1.14 %. We demonstrate dye degradation under NIR illumination using SrYbF:1 %Tm³⁺@CaF₂, highlighting the efficiency of these UCNPs and their ability to trigger photoprocesses.

中文翻译：

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具有生物相容性 CaF2 壳的小型碱土基纳米颗粒中的明亮红外到紫外/可见光上转换。

上转换纳米颗粒（UCNP）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 ₂壳的亚15 nm碱土稀土氟化物UCNP（M 1− x _{Ln x} F ₂₊ x _，MLnF）的近红外到紫外/可见光发射。^{我们合成了 8 种掺杂 Yb 3+}和 Tm ³⁺的碱土主体材料，其中碱土 (M) 涵盖 Ca、Sr、Ba、MgSr、CaSr、CaBa、SrBa 和 CaSrBa。我们探索 UCNP 的成分、尺寸和镧系元素掺杂相关的发射，重点关注上转换量子产率 (UCQY) 和紫外发射。_{使用14.5 nm SrLuF@CaF 2颗粒在250 W cm} ^-2下实现了2.46 %的UCQY值，占UV总发射的7.3 %。在 10.9 nm SrYbF:1 %Tm ³⁺ @CaF ₂颗粒中，UV 发射增加至 9.9%，UCQY 为 1.14%。^{我们使用 SrYbF:1 %Tm 3+} @CaF ₂演示了近红外照明下的染料降解，突出了这些 UCNP 的效率及其触发光处理的能力。