Reversible multiplexing analog and digital optical information storage in Eu3+ doped perovskite-type photochromic materials

Photochromic materials have received increasing interest benefited by its promising application in anti-counterfeiting and erasable optical information storage with the rapid development of the information age. In this work, we have reported a perovskite configuration SrHfO3:Eu3+ photochromic powders, displaying the color changed from white to brown upon UV light irradiation, and it can be bleached by 365 nm light or heat treatment. Based on the energy transfer, the Eu3+ ions doped into SrHfO3 host to obtain luminescence modulation attribute to the special excitation (302 and 396 nm) and emission (614 nm) properties, and the more efficient luminescence modulation is excited at 396 nm. The storage of verbal, images and digital signal can be realized by UV light irradiation, then the stored information can be read out through 254 nm light, and the recording information can be erased using 365 nm light illumination. In addition, the anti-counterfeiting application has achieved by employing alternating UV and 365 nm light illumination. Furthermore, the stored information undergoes several cycles with almost no degradation of "written in", "read out" and "erased", displaying excellent fatigue resistance and reversibility. These results suggest that the perovskite configuration SrHfO3:Eu3+ photochromic material has promising multi-functional application in optical information storage and anti-counterfeiting.