Tailoring Ultra‐Wide Visible‐NIR Luminescence by Ce3+/Cr3+/Yb3+‐alloying Sc‐Based Oxides for Multifunctional Optical Applications

Abstract Visible‐to‐near‐infrared (VIS‐NIR) luminescent materials are in great demand in the field of non‐destructive testing such as component determination and hyperspectral imaging. Although Cr 3+ ‐activated phosphors are widely reported, controllable tailoring ultra‐wide VIS‐NIR luminescence excited by blue light is still a challenge. The strategies of cationic substitution and energy transfers are effective for adjusting the luminescence of Cr 3+ ‐activated phosphors. In this work, a series of Cr 3+ ‐doped Sc‐based solid solution phosphors (Ba 3‐m Sr m Sc 4 O 9 :Cr 3+ ) are reported. Under the excitation of blue light, these phosphors exhibit broadband emission due to the different luminescence centers induced by Cr 3+ occupying different cationic sites. Because of the weaker crystal field strength, Cr 3+ realizes a broadband emission with a longer peak position (λ em = 820 nm) and broader full width at half maximum (FWHM≈182 nm) in Ba 2 SrSc 4 O 9 . Furthermore, Ce 3+ /Yb 3+ ions are introduced into Ba 2 SrSc 4 O 9 :Cr 3+ , achieving an ultra‐wide VIS‐NIR luminescence (460–1200 nm) by the Ce 3+ →Cr 3+ →Yb 3+ multiple energy transfers. Designing energy transfers is beneficial to improve the quantum efficiency and weaken the thermal quenching. Finally, the NIR phosphor‐converted light‐emitting diode (pc‐LED) fabricated by Ba 2 SrSc 4 O 9 :Cr 3+ demonstrates great potential in night‐vision and water component detection. This work provides an effective design idea for controllable tailoring ultra‐wide VIS‐NIR luminescence by chemical substitution and energy transfer.