title: Microwave-assisted synthesis and up-down conversion luminescent properties of multicolor hydrophilic LaF3:Ln3+ nanocrystals.
abstract: Monodisperse water-soluble LaF(3):Ln(3+) nanocrystals (NCs) have been successfully fabricated via a fast, facile and environmentally-friendly microwave-assisted modified polyol process with polyvinylpyrrolidone (PVP) as an amphiphilic surfactant. The obtained NCs can be well dispersed in hydrophilic solutions with small sizes in the range of 9-12 nm. The LaF(3):Ln(3+) NCs (Ln = Eu, Nd, Ce, Tb, Yb, Er, Yb, Ho and Yb, Tm) have the unique feature of up-down conversion from visible to NIR emission owing to the ladder-like arranged energy levels of Ln(3+) and in particular, the high efficiency upconversion of the two-photon, obtained from excitation by a continuous 980 nm laser. This investigation focuses on both the up and down conversion fluorescence properties of water-soluble monodisperse crystalline LaF(3):Ln(3+) NCs in such a small size. Furthermore, the three-dimensional PDMS rod-like fluorescence displays and a silica surface modification by a core/shell structure on the obtained NCs can improve the biocompatibility, indicating potential applications in optical 3D devices and as bio-probes.
authors.affiliation: State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, PR China.
authors.forename: Feifei
authors.initials: F
authors.lastname: Li
authors.forename: Chunguang
authors.initials: C
authors.lastname: Li
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Liu
authors.forename: Tianyu
authors.initials: T
authors.lastname: Bai
authors.forename: Wenjun
authors.initials: W
authors.lastname: Dong
authors.forename: Xiao
authors.initials: X
authors.lastname: Zhang
authors.forename: Zhan
authors.initials: Z
authors.lastname: Shi
authors.forename: Shouhua
authors.initials: S
authors.lastname: Feng