Achieving Broadband NIR Emission in Fe³⁺‐Activated ALaBB′O₆ (A = Ba, Sr, Ca; B–B′ = Li–Te, Mg–Sb) Phosphors via Multi‐Site Ionic Co‐Substitutions

Abstract

Phosphor‐converted near‐infrared (NIR) LEDs are becoming increasingly demanded as miniature, portability, and broad emission spectrum. In this work, a class of Fe3+‐activated double perovskite structured is reported ALaBB′O6 (A = Ba, Sr, Ca; B–B′ = Li–Te, Mg–Sb) phosphors. Through the co‐substitution strategy at the A‐site and B‐B' sites, the emission spectral intensity and position of Fe3+ ions can be tuned. Finally, by utilizing Ca2+ at the A‐site and Mg–Sb co‐substitution for Li–Te, long‐wave NIR emission centered at 995 nm in CaLaMgSbO6: 0.6%Fe3+ with a full width at half maximum of 147 nm and internal quantum efficiency of 54.05% is achieved. The effects of the double perovskite crystal structure on Fe3+ photoluminescence properties are comprehensively analyzed. NIR LEDs are fabricated by encapsulating UV chips with the synthetic CaLaMgSbO6: 0.6%Fe3+ phosphors, and their application value in night vision, nondestructive biological monitoring, and NIR detection is evaluated.

Realizing Ultrabroadband NIR-II Emission and Wide-Range Wavelength Tuning in Cr4+-activated ABO2 (A = Li, Na; B = Al, Ga) Phosphors

“…But the lattice occupancy of Cr 4+ in the matrix not only needs to consider the coordination environment but also the radius and valence state of the substituted ions. The radius difference ratio induced by ion replacement can be expressed by the following formula: D r = R s ⁡ false( CN false) − R d ⁡ false( CN false) R s ⁡ false( CN false) × 100 where D r represents the percentage of radius difference, R s and R d represent the radius of the substituted center ion and the radius of the doped ion, respectively, and CN represents the coordination number. Table summarizes ion radius and valence states in ABO 2 and the calculated percentage of radius difference caused by Cr 4+ substitution.…”

Highly efficient and thermostable far-red phosphor for promoting root growth in plants

“…In previous studies, it has been found that introducing Cr 3+ , 14 Fe 3+ , 15,16 Ni 2+ , 17,18 Bi 2+ , 19,20 Eu 2+ , 21,22 and Yb 3+ 23,24 ions in inorganic materials can produce near-infrared photoluminescence. Among these potential candidates, Cr 3+ has become a popular far-red emitting activator applied in plant growth, as it can not only be excited efficiently by blue-violet light but also its emission can be controlled by the crystal field strength.…”