New function of the Yb(3+) ion as an efficient emitter of persistent luminescence in the short-wave infrared

The trivalent ytterbium (Yb(3+)) ion has been extensively used as an emitter in short-wave infrared (SWIR) lasers, a sensitizer to activate other lanthanide ions for up-conversion luminescence, and a spectral converter in Ln(3+)-Yb(3+) doubly doped quantum cutting phosphors. Here we report a new function of the Yb(3+) ion—as an efficient emitting center for SWIR persistent luminescence. We have developed the first real SWIR persistent phosphor, MgGeO(3):Yb(3+), which exhibits very-long persistent luminescence at around 1000 nm for longer than 100 h. The MgGeO(3):Yb(3+) phosphor is spectrally transparent to visible/near-infrared light (~400–900 nm) and is a promising ultraviolet-to-SWIR spectral convertor. The MgGeO(3):Yb(3+) phosphor also exhibits a photostimulated persistent luminescence capability, where the SWIR persistent emission in an ultraviolet-light pre-irradiated sample can be rejuvenated by low-energy light (white or red light) stimulation. The MgGeO(3):Yb(3+) phosphor is expected to have promising applications in biomedical imaging, night-vision surveillance and photovoltaics.