An ultrafast route to prepare up-converting single β-phase NaYF₄:Yb³⁺,Ln³⁺ (Ln: Er, Tm, or Tb) short nanorods (UCNRs) of high quality was developed. This new procedure affords reactive-surface nanorods that are easily coated by direct injection of suitable capping ligands. Thus highly crystalline nanorods with excellent UC fluorescence and good solvent-selective dispersion are obtained, which represents a significant advance in the field and enlarges their use for biomedical and other technological applications. Unlike other methodologies, the short reaction time provides a kinetic control over crystallization processes, and the β-phase and rod morphology is preserved regardless of the optically active Ln³⁺ ion. The UC emission was finely tuned by using the most popular Yb³⁺/Tm³⁺ and Yb³⁺/Er³⁺ pairs. More importantly, UCNRs doped with the unusual Yb³⁺/Tb³⁺ pair, with no ladder-like energy levels, provided a nice emission upon near-infrared excitation, which constitutes the first example of phonon-assisted cooperative sensitization to date in pure β-NaYF₄ nanocrystals.

中文翻译：

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超快合成和高品质的涂料β-NaYF ₄：镱³⁺，LN ³⁺短纳米棒

开发了一种制备上转换单βNaYF ₄：Yb ³⁺，Ln ³⁺（Ln：Er，Tm或Tb）高品质短纳米棒（UCNRs）的超快路线。该新方法提供了可通过直接注入合适的封端配体轻松涂覆的反应性表面纳米棒。因此，获得了具有优异的UC荧光和良好的溶剂选择性分散性的高度结晶的纳米棒，这代表了该领域的重大进步，并扩大了其在生物医学和其他技术应用中的用途。与其他方法不同，较短的反应时间提供了对结晶过程的动力学控制，并且无论旋光性Ln ³⁺如何，都可以保持β相和棒状形态离子。通过使用最流行的Yb ³⁺ / Tm ³⁺和Yb ³⁺ / Er ³⁺对对UC发射进行了微调。更重要的是，掺杂有异常Yb ³⁺ / Tb ³⁺对的UCNRs没有阶梯状能级，在近红外激发下提供了良好的发射，这是迄今为止纯声子辅助协同增感的第一个例子β-NaYF _4个纳米晶体。