Enhanced dual-wavelength sensitive upconversion luminescence of BiPO4:Yb3+/Er3+ phosphors by Sc3+ doping

A series of BiPO 4 :Yb 3+ /Er 3+ samples with different concentrations of Sc 3+ ions were prepared by two different methods: one is solvothermal synthesis process and subsequent calcination route, and the other is solid-state reaction method. On one hand, hexagonal and monoclinic phases of BiPO 4 :Yb 3+ /Er 3+ were successfully obtained by the above two synthesis methods, respectively, and the UC luminescence intensity depended a lot on the crystalline phases. On the other hand, the dual-wavelength sensitive UC emission properties of BiPO 4 :Yb 3+ /Er 3+ /Sc 3+ were firstly investigated. It was found the UC emission intensity was significantly enhanced by introducing appropriate Sc 3+ ions to the system whether under excitation at 980 nm or 1550 nm. Moreover, the UC emission mechanisms under the excitation at 980 as well as 1550 nm were also proposed on the base of experimental results.