Synthesis and luminescent performances of Ca2AlNbO6:Cr3+ perovskite phosphor

Due to their applications in lighting, imaging, security, night vision, optoelectronics and other fields, far-red to near-infrared luminescence materials have attracted significant interest. Efficient pure phase Ca 2 AlNbO 6 :Cr 3+ phosphor is synthesized in air. The excitation spectrum of Ca 2 AlNbO 6 :Cr 3+ can be observed in the range of 260–700 nm because of the transitions 4 A 2 → 4 T 1 ( 4 P), 4 T 1 ( 4 F), and 4 T 2 ( 4 F) of the Cr 3+ ions. Ca 2 AlNbO 6 :Cr 3+ emits far-red to near-infrared light with peaks at 745 and 755 nm in the range of 650–880 nm due to the transitions 2 E → 4 A 2 and 4 T 2 ( 4 F) → 4 A 2 of the Cr 3+ ion. The concentration dependent spectra of Ca 2 AlNbO 6 :Cr 3+ confirm that 0.4 mol% is the optimal concentration of Cr 3+ ions in Ca 2 AlNbO 6 :Cr 3+ . The emission spectra under different excitation wavelength and time-resolved emission spectra indicate that Cr 3+ is the only luminous center in Ca 2 AlNbO 6 :Cr 3+ . As Cr 3+ is added from 0.2 mol% to 1.0 mol%, the lifetime of Ca 2 AlNbO 6 :Cr 3+ decreases in turn from 3.25 ms to 2.82 ms. The temperature dependent spectra prove a good thermal stability of Ca 2 AlNbO 6 :Cr 3+ . The paper content can be applied to develop new Cr 3+ -doped luminescence materials in the future.