NIR persistent luminescence phosphor Zn1.3Ga1.4Sn0.3O4:Yb3+,Er3+,Cr3+ with 980 nm laser excitation

Abstract

As a new type of optical probe for biological imaging, persistent luminescence (PersL) materials with near-infrared (NIR) emission have aroused great interest for their excellent signal-to-noise ratio and deep penetration in biological tissues. However, their application in long-term biological imaging is strongly restricted because the excitation light of most NIR PersL-emitting phosphors locates in the ultraviolet (UV) region, which is harmful to the body. It is urgent to develop a NIR PersL phosphor under the excitation of NIR light. Herein, a NIR PersL-emitting phosphor, Zn_1.3Ga_1.4Sn_0.3O₄:Yb³⁺,Er³⁺,Cr³⁺, excited by a 980 nm laser, was successfully prepared via a high-temperature solid-state reaction. The phosphor Zn_1.3Ga_1.4Sn_0.3O₄:Yb³⁺,Er³⁺,Cr³⁺ not only shows efficient green/red emission from Er³⁺ but also displays NIR PersL emission from Cr³⁺ owing to the energy transfer of Yb³⁺ → Er³⁺ → Cr³⁺. Surprisingly, the intense NIR PersL could be induced by UV, visible and 980 nm NIR light irradiation, for which the possible mechanism is also proposed according to photoluminescence (PL) and thermoluminescence (TL) spectra. Results indicate that the present phosphor Zn_1.3Ga_1.4Sn_0.3O₄:Yb³⁺,Er³⁺,Cr³⁺ possesses intense NIR PersL under the excitation of 980 nm light, which offers an efficient method to design the NIR PersL with the excitation of NIR laser.