Tuning upconversion through energy migration in core-shell nanoparticles.
Photon upconversion is promising for applications such as biological imaging, data storage or solar cells. Here, we have investigated upconversion processes in a broad range of gadolinium-based nanoparticles of varying composition. We show that by rational design of a core-shell structure with a set of lanthanide ions incorporated into separated layers at precisely defined concentrations, efficient upconversion emission can be realized through gadolinium sublattice-mediated energy migration for a wide range of lanthanide activators without long-lived intermediary energy states. Furthermore, the use of the core-shell structure allows the elimination of deleterious cross-relaxation. This effect enables fine-tuning of upconversion emission through trapping of the migrating energy by the activators. Indeed, the findings described here suggest a general approach to constructing a new class of luminescent materials with tunable upconversion emissions by controlled manipulation of energy transfer within a nanoscopic region.
Department of Chemistry, National University of Singapore, 117543, Singapore.
Feng
F
Wang
Renren
R
Deng
Juan
J
Wang
Qingxiao
Q
Wang
Yu
Y
Han
Haomiao
H
Zhu
Xueyuan
X
Chen
Xiaogang
X
Liu
D004735:Energy Transfer; D005682:Gadolinium / Q000737:chemistry*; D028581:Lanthanoid Series Elements / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D017785:Photons
D028581:Lanthanoid Series Elements; D005682:Gadolinium