摘要
等离激元纳腔可有效调控稀土掺杂纳米晶的上转换发光特性,其不仅能增强上转换发光强度,还可实现上转换发光光谱的调节.然而,目前利用纳腔进行上转化发光光谱调节的研究主要基于系综实验.相比系综实验,单颗粒实验由于可对同一颗上转换纳米晶进行对比研究,因而能够排除系综样品非均匀性对实验的影响.本文基于原子力显微镜原位纳米操纵技术将单颗粒Yb^(3+)/Tm^(3+)共掺杂纳米晶与由单根金纳米棒构成的等离激元纳腔进行耦合,实验上对比了同一颗纳米晶与金纳米棒耦合前后上转换发光的光谱、发光寿命和激发功率依赖特性的变化.实验结果与理论上通过结合电磁仿真和速率方程模拟得到的结果相符.研究结果表明,等离激元纳腔调控纳米晶上转换发光光谱是激发场增强效应、Purcell效应和辐射效率变化三方面效应共同作用的结果.
Plasmonic nanocavities can effectively modulate the upconversion luminescence properties of lanthanide doped upconversion nanocrystals(UCNCs),which not only enhances the luminescence intensity,but also modifies the luminescence spectrum.However,currently reported studies of upconversion luminescence spectrum modulation by using nanocavities are mainly based on ensemble experiments.Compared with ensemble experiments,single-particle experiments facilitate the comparative studies for the same upconversion nanocrystal and therefore the influence of inhomogeneity in ensemble samples can be avoided.Here in this work,we couple a single particle of Yb^(3+)/Tm^(3+)co-doped nanocrystal with a plasmonic nanocavity composed of a single gold nanorod by using the in-situ nano-manipulation technique based on an atomic force microscope.Experimentally,we compare the upconversion luminescence spectra,upconversion luminescence lifetimes and excitation-power dependent upconversion luminescence intensities of the same single nanocrystal before and after coupling with the single gold nanorod.The experimental measurements are consistent with the theoretical calculations from rate equations combined with electromagnetic simulations.The results indicate that the plasmaonic nanocavity modulated nanocrystal upconversion luminescence spectrum is the combined result of three effects:the excitation field enhancement effect,the Purcell effect and the change of radiation efficiency.
作者
孟勇军
李洪
唐建伟
陈学文
Meng Yong-Jun;Li Hong;Tang Jian-Wei;Chen Xue-Wen(School of Physics,Huazhong University of Science and Technology,Wuhan 430074,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2022年第2期289-297,共9页
Acta Physica Sinica
基金
国家自然科学基金(批准号:11874166,12004130)资助的课题。
关键词
上转换纳米晶
等离激元纳腔
光谱调控
纳米操纵
upconversion nanocrystal
plasmonic nanocavity
spectrum modulation
nano-manipulation
