Ishii Ayumi, Adachi Yuya, Hasegawa Ayaka, Komaba Miyu, Ogata Shuhei, Hasegawa Miki
College of Science and Engineering, Aoyama Gakuin University, Sagamihara, Kanagawa, Japan.
JST, PRESTO, Kawaguchi, Japan.
Sci Technol Adv Mater. 2018 Dec 18;20(1):44-50. doi: 10.1080/14686996.2018.1558911. eCollection 2019.
Multicolor upconversion luminescence of Er was successfully enhanced by optimizing the interface in dye-coordinated nanoparticles with a core/shell structure. Red and green upconversion emissions of Er were obtained at the interface of oxide nanoparticles via the intramolecular energy transfer from the coordinating squaraine dye with high light-absorption ability, which was more efficient than emissions through the energy transfer from metal ions such as Yb. Additionally, CaF nanoparticles as a core material minimized the energy loss with nonradiative downward relaxations in Er, resulting in the observation of unusual blue upconversion emissions from the upper energy level of Er by nonlaser excitation using a continuous-wave (CW) Xe lamp at an excitation power of 1.2 mW/cm.
通过优化具有核壳结构的染料配位纳米粒子中的界面，成功增强了铒的多色上转换发光。通过具有高光吸收能力的配位方酸菁染料的分子内能量转移，在氧化物纳米粒子的界面处获得了铒的红色和绿色上转换发射，这比通过诸如镱等金属离子的能量转移产生的发射更有效。此外，作为核心材料的氟化钙纳米粒子将铒中无辐射向下弛豫导致的能量损失降至最低，从而在1.2 mW/cm的激发功率下使用连续波（CW）氙灯进行非激光激发时，观察到了来自铒高能级的异常蓝色上转换发射。
