Plasmon enhanced near-infrared quantum cutting of KYF₄: Tb³⁺, Yb³⁺ doped with Ag nanoparticles.

Novel quantum cutting (QC) phosphor KYF4:  Tb3+, Yb3+ doped Ag nanoparticles (NPs) was prepared by using the sol-gel method. Plasmon enhanced near-infrared (NIR) QC involving Yb3+ ion at 975 nm (2F5/2→2F7/2) emission was achieved under the excitation of 374 nm (7F6→5D3) and 485 nm (7F6→5D4) of Tb3+ ions, respectively. The effect of Ag NPs on NIR QC luminescence was investigated, and the results show that QC luminescence intensity first increases, then decreases with the increase of the Ag NPs concentration. The maximum enhancement factor is about 1.9 when the concentration of Ag NPs is 0.5%. Our study may have potential application in the field of silicon-based solar cells.