Up-conversion Persistent Luminescence of a 980 nm Laser Activated Zn3Ga2(GexSn1−x)O8:Yb,Er,Cr Phosphors

Zn 3 Ga 2 (Ge x Sn 1−x )O 8 :Yb,Er,Cr phosphors with different doping ratio of Ge/Sn were prepared by high temperature solid-state method. After excited at 270 nm with a xenon lamp for 15 min, the persistent luminescence (PL) of Zn 3 Ga 2 (Ge x Sn 1−x )O 8 :Yb,Er,Cr phosphor can last more than 60 min. Under the excitation at 980 nm, Zn 3 Ga 2 (Ge x Sn 1−x )O 8 :Yb,Er,Cr phosphors can generate effective up-conversion emissions from Er 3+ ions at 410 nm, 525 nm, 550 nm, 660 nm and Cr 3+ ions around 700 nm. Besides, after ceasing irradiation, Zn 3 Ga 2 (Ge x Sn 1−x )O 8 :Yb,Er,Cr phosphors show up-conversion persistent luminescence (UCPL) from Cr 3+ ions around 700 nm. Moreover, Zn 3 Ga 1.995 (Ge 0.3 Sn 0.7 ) O 8 :Yb 3+ ,Er 3+ ,Cr 3+ phosphor is optimal with the best persistent luminescent and up-conversion persistent luminescent properties. In short, owing to the long afterglow time, strong up-conversion emissions and novel up-conversion persistent luminescence, the as-prepared Zn 3 Ga 2 (Ge x Sn 1−x )O 8 :Yb,Er,Cr phosphors can be potentially applied in a wide range of fields, such as security materials, coating materials, infrared detection, fluorescent label, tracer and testing.