Li Qiqing, Xie Xiaoyu, Wu Han, Chen Haoran, Wang Wang, Kong Xianggui, Chang Yulei
State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, Jilin, People's Republic of China.
Nano Lett. 2023 Apr 26;23(8):3444-3450. doi: 10.1021/acs.nanolett.3c00495. Epub 2023 Apr 4.
Highly doped lanthanide luminescent nanoparticles exhibit unique optical properties, providing exciting opportunities for many ground-breaking applications, such as super-resolution microscopy, deep-tissue bioimaging, confidentiality, and anticounterfeiting. However, the concentration-quenching effect compromises their luminescence efficiency/brightness, hindering their wide range of applications. Herein, we developed a low-temperature suppression cross-relaxation strategy, which drastically enhanced upconversion luminescence (up to 2150-fold of green emission) in Er-rich nanosystems. The cryogenic field opens the energy transport channel of Er multiphoton upconversion by further suppressing phonon-assisted cross-relaxation. Our results provide direct evidence for understanding the energy loss mechanism of photon upconversion, deepening a fundamental understanding of the upconversion process in highly doped nanosystems. Furthermore, it also suggests the potential applications of upconversion nanoparticles for extreme ambient-temperature detection and anticounterfeiting.
高掺杂镧系发光纳米粒子具有独特的光学性质，为许多开创性应用提供了令人兴奋的机会，如超分辨率显微镜、深部组织生物成像、保密和防伪。然而，浓度猝灭效应会损害其发光效率/亮度，阻碍其广泛应用。在此，我们开发了一种低温抑制交叉弛豫策略，该策略显著增强了富铒纳米体系中的上转换发光（绿色发射增强至2150倍）。低温场通过进一步抑制声子辅助交叉弛豫，打开了铒多光子上转换的能量传输通道。我们的结果为理解光子上转换的能量损失机制提供了直接证据，加深了对高掺杂纳米体系中上转换过程的基本理解。此外，它还暗示了上转换纳米粒子在极端环境温度检测和防伪方面的潜在应用。
