Cheng Xingwen, Ge Huan, Wei Yang, Zhang Kun, Su Wenhong, Zhou Jimin, Yin Lisha, Zhan Qiuqiang, Jing Su, Huang Ling
Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) , Nanjing Tech University , Nanjing 211816 China.
School of Chemistry and Molecular Engineering , Nanjing Tech University , Nanjing 211816 China.
ACS Nano. 2018 Nov 27;12(11):10992-10999. doi: 10.1021/acsnano.8b04988. Epub 2018 Oct 16.
The perfect energy level overlap of H, S, and F in Er ions with those of F, F/S, and F in adjacently codoped Ho ions allows efficient interenergy transfer. Therefore, in addition to routine activators, Er or Ho can further act as sensitizers to transfer the upconverted energy to nearby Ho or Er, resulting in enhanced upconversion luminescence due to the emission overlap. Proper codoping of Er/Ho or Ho/Er obviously elevates the maximum doping concentration (thus producing additional upconverted photons) to a level higher than that causing luminescence quenching and significantly enhances upconversion emissions compared with those of singly Er or Ho-doped host materials. Indeed, the so-far strongest red upconversion emission under 1532 nm excitation was obtained in LiYF:Er/Ho@LiYF nanoparticles and Ho-sensitized Er upconversion emissions excited by 1150 nm laser was simultaneously discovered. With great enhancement compared with that of singly Ho doped counterparts, this work demonstrates the generality and rationality of our design strategy.
铒离子中H、S和F与相邻共掺杂钬离子中的F、F/S和F的完美能级重叠允许有效的能量转移。因此，除了常规激活剂外，铒或钬还可以进一步作为敏化剂，将上转换能量转移到附近的钬或铒，由于发射重叠导致上转换发光增强。铒/钬或钬/铒的适当共掺杂明显将最大掺杂浓度（从而产生额外的上转换光子）提高到高于导致发光猝灭的水平，并且与单掺杂铒或钬的主体材料相比，显著增强了上转换发射。实际上，在LiYF:Er/Ho@LiYF纳米颗粒中获得了迄今为止在1532 nm激发下最强的红色上转换发射，并且同时发现了由1150 nm激光激发的钬敏化铒上转换发射。与单掺杂钬的对应物相比有很大增强，这项工作证明了我们设计策略的通用性和合理性。
