Plasmonic modulation of the upconversion fluorescence in NaYF4:Yb/Tm hexaplate nanocrystals using Gold nanoparticles or nanoshells
H. Zhang, Y. Li, I.A. Ivanov, Q. Qu, Y. Huang, and X. Duan
Angew Chemie Intl. Ed. 49, 2865-2868 (2010)
Automatic upgrade: Attachment of gold nanoparticles (NPs) onto upconversion nanocrystals (NCs) results in plasmonic interactions that lead to a significant enhancement of upconversion emission of more than 2.5. Conversely, formation of a gold shell greatly suppresses the NC emission because of considerable scattering of excitation irradiation (see picture; a=NC before seed attachment; b, c=NC with attached Au NPs; c=NC with Au shell; scale bar=50 nm).