Open AccessCharacterizing the luminescent properties of upconversion nanoparticles in single and densely packed state
Author(s) -
Xiaohu Chen,
Zhengyu Gui,
Yong Liang,
Xin Jin,
Simin Li,
Pengjiu Zhao,
Zhangsen Yu,
Aiguo Wu,
Shoupeng Liu,
Hui Li
Publication year - 2019
Publication title -
journal of innovative optical health sciences/journal of innovation in optical health science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.421
H-Index - 24
eISSN - 1793-5458
pISSN - 1793-7205
DOI - 10.1142/s1793545818410043
Subject(s) - luminescence , excitation , nanoparticle , photon upconversion , particle (ecology) , materials science , absorption (acoustics) , packed bed , molecular physics , ground state , atomic physics , analytical chemistry (journal) , nanotechnology , chemistry , optoelectronics , physics , composite material , oceanography , chromatography , quantum mechanics , geology
Luminescent properties of Er[Formula: see text]- and Yb[Formula: see text]- co-doped CaF 2 upconversion nanoparticles (UCNPs) were investigated in single particle and densely-packed states with a custom-built microscope. The single UCNPs exhibit linear dependency of luminescent intensity on excitation power while the densely-packed UCNPs exhibit a 2-order power law-dependency indicating a two-photon absorption process. Time-domain luminescence intensity measurements were performed and the curves were fitted to excitation[Formula: see text]emission rate functions based on a simplified three-state model. The results indicate that the intermediates in single particles are much less and saturated in a short time, and there are strong couplings of the ground states and intermediate states between neighboring UCNPs in densely packed UCNPs.