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

Abstract

Zn₃Ga₂(Ge_xSn_1-x)O₈: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 Zn₃Ga₂(Ge_xSn_1-x)O₈:Yb,Er,Cr phosphor can last more than 60 min. Under the excitation at 980 nm, Zn₃Ga₂(Ge_xSn_1-x)O₈:Yb,Er,Cr phosphors can generate effective up-conversion emissions from Er³⁺ ions at 410 nm, 525 nm, 550 nm, 660 nm and Cr³⁺ ions around 700 nm. Besides, after ceasing irradiation, Zn₃Ga₂(Ge_xSn_1-x)O₈:Yb,Er,Cr phosphors show up-conversion persistent luminescence (UCPL) from Cr³⁺ ions around 700 nm. Moreover, Zn₃Ga_1.995(Ge_0.3Sn_0.7) O₈:Yb³⁺,Er³⁺,Cr³⁺ 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 Zn₃Ga₂(Ge_xSn_1-x)O₈: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.

Keywords: Persistent luminescence; Solid-state reaction; Up-conversion luminescence; Up-conversion persistent luminescence; Zn3Ga2(GexSn1−x)O8:Yb,Er,Cr.