Photochromism and Long Persistent Luminescence in Pr^<3+>-Doped Garnet Transparent Ceramic via Ultraviolet or Blue Light Up-conversion Charging

Multifunctional phosphors with photochromism and persistent luminescent (PersL) properties have attracted increasing interest owing to the capability of absorbing the photon energy and trapping the generated carriers via defects. However, the opacity of materials compromises the enhancement of photochromism and PersL properties; besides, the need of high energy excitation light source limits their applicability. To bridge these obstacles, we report Pr3+-doped Y3Al2Ga3O12 transparent ceramic with in-line transmittance over 80% at 1800 nm, which exhibits strong red PersL after several minutes ultraviolet (UV) light or blue light up-conversion charging. The luminance duration time can reach more than 7 h at 0.32 mcd /m2 threshold value after UV light charging. Interestingly, the phosphor also displays photochromic properties with robust fatigue resistance, i.e., the color changes from light green to red by UV/blue light illumination and is bleached at 300℃. The nature of trap centers, trapping and detrapping processes are explored based on thermoluminescence and electron spin resonance. Finally, the mechanism of photochromism and PersL are discussed by using vacuum referred binding energy diagram. This work opens new avenues for future research on multifunctional materials and brings potential applications in optical information encryption media and optical sensors

Full spectrum core-shell phosphors under ultraviolet excitation

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Massive red-shifting of Ce3+ emission by Mg2+ and Si4+ doping of YAG:Ce transparent ceramic phosphors

Massive red-shifting of Ce3+ emission by Mg2+ and Si4+ doping of YAG:Ce transparent ceramic phosphor

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Preparation and luminescent properties of highly transparent Y3Ga5O12:M3+ (M = Dy, Cr) ceramics

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