Broadband near-infrared emission improvement of Cr3+ doped phosphors via co-doping Bi3+ ions

Cr 3+ doped luminescence materials have been investigated widely and their luminescence property improvements are becoming a research hotspot by the researchers. In this work, we study the broadband near-infrared emission improvement and synthesis of Cr 3+ doped perovskite (Li 1.6 Mg 1.6 Sn 2.8 O 8 :Cr 3+ ) via co-doped Bi 3+ ions. The crystal structure, morphology, and luminescence properties of samples are investigated, respectively. Photoluminescence (PL) spectra of Li 1.6 Mg 1.6 Sn 2.8 O 8 :R (R = Cr 3+ , Cr 3+ /Bi 3+ ) in the range of 650 - 1250 nm are observed with a broad PL band and ∼186 nm full width at half maximum due to the 4 T 2 ( 4 F) → 4 A 2 transition of Cr 3+ ion in weak crystal field. The spectral intensity of Li 1.6 Mg 1.6 Sn 2.8 O 8 :Cr 3+ can be enhanced ∼2.4 times because of the change of crystal field when the co-doped Bi 3+ ions is ∼4 mol%. The good luminous thermal stability of Li 1.6 Mg 1.6 Sn 2.8 O 8 :Cr 3+ , Bi 3+ is confirmed by using PL spectra under the temperature from 300 to 450 K. The concentration/thermal quenching and luminescence mechanisms of Li 1.6 Mg 1.6 Sn 2.8 O 8 :R (R = Cr 3+ , Cr 3+ /Bi 3+ ) are analyzed and explained. This paper content can provide help for the improving emission of Cr 3+ doped luminescence materials.