Efficient near-infrared quantum cutting in Tb3+,Yb3+ codoped LuPO4 phosphors

Tb3+ and Yb3+ codoped LuPO4 phosphors were prepared by the reverse-strike co-precipitation method. The obtained LuPO4:Tb3+,Yb3+ phosphors were characterized by X-ray diffraction (XRD), photoluminescence (PL) spectra and decay kinetics to understand the near-infrared quantum cutting (QC) phenomena. The XRD results showed that all the phosphors exhibited good crystallinity and had a pure tetragonal phase of LuPO4. The experimental results showed that the strong green emission around 545 nm from Tb3+ (5D4→7F5) and near-infrared (NIR) emission at 1003 nm from Yb3+ (2F5/2→2F7/2) of LuPO4:Tb3+,Yb3+ phosphors were observed under 489 nm excitation, respectively. The Yb3+ concentration dependence on luminescent properties and lifetimes of both the visible and NIR emissions were also investigated. The quenching concentration of Yb3+ ions approached as high as 10 mol.%. The excellent luminescence properties of the LuPO4:Tb3+,Yb3+ indicated its potential application in improving the energy conversion eficiency of the silicon based solar cells by converting one blue photon to two NIR ones.