Broadband and tunable near-infrared emission of CaMg2Al16O27:Fe3+ with multi-site engineering

Near-infrared (NIR) light has low scattering coefficient, strong penetration capability, and selective absorption by specific molecular features, causing that the developing broadband and high-efficiency NIR source is very important. Fe 3+ as a promising NIR activator ion have garnered increasing attention due to its broad spectral characteristics, environmental benignity, tunable emission, and non-toxicity. In this work, CaMg 2 Al 16 O 27 :Fe 3+ with hexagonal structure and P-6 m2(187) space group is selected as the research system. A broadband NIR emission in the range of 650 – 890 nm is observed because of the transition 4 T 1 ( 4 G) → 6 A 1 ( 6 S) of Fe 3+ ion, containing two PL peaks at ∼ 750 and 808 nm derived from Fe 3+ ions in [FeO 4 ] tetrahedron and [FeO 6 ] octahedron, respectively. CaMg 2 Al 16 O 27 :Fe 3+ @PDMS film is prepared and NIR illumination by combining the CaMg 2 Al 16 O 27 :Fe 3+ @PDMS film with a ∼ 262 nm LED chip is investigated. This study confirms the potential applications of CaMg 2 Al 16 O 27 :Fe 3+ in non-invasive detection technologies, night vision, and biological imaging and provides important insights for the design and development of Fe 3+ -doped NIR phosphors.