Photostimulated near-infrared persistent luminescence as a new optical read-out from Cr³⁺-doped LiGa₅O₈.

In conventional photostimulable storage phosphors, the optical information written by x-ray or ultraviolet irradiation is usually read out as a visible photostimulated luminescence (PSL) signal under the stimulation of a low-energy light with appropriate wavelength. Unlike the transient PSL, here we report a new optical read-out form, photostimulated persistent luminescence (PSPL) in the near-infrared (NIR), from a Cr(3+)-doped LiGa₅O₈ NIR persistent phosphor exhibiting a super-long NIR persistent luminescence of more than 1,000 h. An intense PSPL signal peaking at 716 nm can be repeatedly obtained in a period of more than 1,000 h when an ultraviolet-light (250-360 nm) pre-irradiated LiGa₅O₈:Cr(3+) phosphor is repeatedly stimulated with a visible light or a NIR light. The LiGa₅O₈:Cr(3+) phosphor has promising applications in optical information storage, night-vision surveillance, and in vivo bio-imaging.