Deep-red-emitting Mg2InSbO6:Mn4+ phosphors with a double-perovskite structure for plant-cultivation LEDs: Synthesis and photoluminescence properties

In this study, novel deep-red-emitting Mg 2 InSbO 6 :Mn 4+ phosphors were prepared through a high-temperature solid-state reaction. The as-prepared phosphors belong to the perovskite structure with the space group of R 3 ‾ (No.148). The calculated energy gap value of Mg 2 InSbO 6 is ~1.788 eV. Emission spectrum of the Mg 2 InSbO 6 :0.3%Mn 4+ was obtained under 301 nm excitation, which centered 665 nm due to the 2 E g → 4 A 2g transition. The optimum concentration of Mg 2 InSbO 6 : x Mn 4+ is confirmed to 0.3% mol, and the concentration quenching effect is ascribed to the dipole–dipole interaction. The relative temperature-dependent PL spectra demonstrate that phosphors possess commendable repeatability and high activation energy . The chromaticity shift diagram shows the phosphors have good resistance of color drifting. The Mg 2 InSbO 6 :0.3%Mn 4+ phosphor has a high color purity of 99.8%. Furthermore, a red light-emitting diode is fabricated with Mg 2 InSbO 6 :0.3%Mn 4+ phosphor and a 365 nm near-ultraviolet chip. The emission spectrum of the red LED is perfectly overlapped with plant pigments (chlorophyll a and chlorophyll b ) absorption spectrum . Thus, Mn 4+ -activated Mg 2 InSbO 6 :Mn 4+ phosphors have the potential to apply in plant-cultivation LEDs.