title: Ion-redistribution induced efficient upconversion in β-NaYF4:20%Yb3+,2%Er3+microcrystals with well controlled morphology and size.
abstract: We develop an efficient green upconversion (UC) β-NaYF4:20%Yb3+,2%Er3+microcrystal with well controlled morphology and size by hydrothermal method using two different chelating agents of CIT and EDTA-2Na via a simple ion-exchange reaction. Importantly, the UC emission efficiency of newly developed CIT and EDTA-2Na β-NaYF4:20%Yb3+,2%Er3+microcrystals is almost as strong as that of commercial counterpart by solid-state method. A proof-of-concept β-NaYF4:20%Yb3+,2%Er3+microcrystal waveguide is demonstrated to extend their applications in modern micro-optoelectronics. The local ion-redistribution process during the ion-exchange reaction, which effectively disperses the locally clustered Yb3+, accounts for the enormously enhanced UC emission in β-NaYF4:20%Yb3+,2%Er3+microcrystals.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Fan
authors.forename: Shikai
authors.initials: S
authors.lastname: Wang
authors.forename: Lu
authors.initials: L
authors.lastname: Yu
authors.forename: Hongtao
authors.initials: H
authors.lastname: Sun
authors.forename: Guojun
authors.initials: G
authors.lastname: Gao
authors.forename: Lili
authors.initials: L
authors.lastname: Hu