Cationic regulation and broadband near-infrared emission properties of Li _1.6 (MgZn) _1.6 Sn _2.8 O ₈ :Cr ³⁺

Abstract Broadband near-infrared (NIR) Cr 3+ -doped luminescence materials with long-wavelength emission peak and high thermal stability are being investigated by many researchers because of the applications in non-destructive testing, intelligent identification, night vision, and biomedical imaging. Herein, Li 1.6 (MgZn) 1.6 Sn 2.8 O 8 :Cr 3+ phosphors are prepared in air via high-temperature solid-state method. NIR emission with ~186 nm full width at half maximum is found due to the 4 T 2 ( 4 F) → 4 A 2 transition of Cr 3+ ion. The co-doped Zn 2+ ions can enhance the emission of Li 1.6 Mg 1.6 Sn 2.8 O 8 :Cr 3+ and the improvement rate can reach ~1.9 times because of the minute changes in the crystal field, which is analyzed by the crystal structure. PL peak of Li 1.6 (MgZn) 1.6 Sn 2.8 O 8 :Cr 3+ has a red-shift from 838 to 870 nm with adding Zn 2+ content from 0 to 1.6. PLE peaks at ~ 356, 430, and 660 nm manifest that the samples can be excited by the ultraviolet (UV), near-UV, blue, even red light. The optimal Cr 3+ concentration is 1 mol% in Li 1.6 Mg 1.6 Sn 2.8 O 8 :Cr 3+ and the optimal Zn 2+ content is 0.2 in Li 1.6 (MgZn) 1.6 Sn 2.8 O 8 :Cr 3+ . Li 1.6 (MgZn) 1.6 Sn 2.8 O 8 :Cr 3+ has potential applications in night vision systems and biomedical imaging for diagnosis. This work provides new idea and method for the improvement of other Cr 3+ doped luminescent materials.