Achieving blue light excitation and broadband NIR-II region emission regulation of ALaMgSbO6: Ni2+ (A=Ca, Sr, Ba) phosphors

Abstract

Obtaining broadband near-infrared (NIR) II region phosphors that can be effectively excited by blue light chips remains a significant challenge in the current construction of compact NIR light sources. In this work, a novel series of Ni²⁺-activated ALaMgSbO₆ (A = Ca, Sr, Ba) double perovskite phosphors were designed and synthesized. By substituting the A-site ions, tunable broadband emission of Ni²⁺ in the NIR-II region was achieved. Experiments and theoretical calculations show that A-site substitution and Ni²⁺ doping have a certain impact on the luminescence performance. When the A-site was occupied by Ca²⁺, the CaLaMgSbO₆: 1.2 % Ni²⁺ phosphor showed the highest emission intensity. Under 440 nm blue light excitation, CaLaMgSbO₆: 1.2 % Ni²⁺ achieved long-wavelength broadband NIR emission centered at 1546 nm with a full width at half maximum (FWHM) of 229 nm and photoluminescence quantum yield of 32.94 %. Finally, CaLaMgSbO₆: 1.2 % Ni²⁺ phosphor was coated on a 440 nm blue light chip to package NIR-LED, verifying its feasibility in material detection and night vision. These results have opened up new ways to develop efficient broadband NIR-II region LED light sources.