Photoluminescence properties of Ba2LaSbO6:Mn4+ deep-red-emitting phosphor for plant growth LEDs

In this work, Ba2LaSbO6:Mn4+ phosphors are prepared successfully in air by solid-state reaction method, which is confirmed by the X-ray powder diffractions patterns, decay curves, the time-resolved emission spectra and luminescence properties. Monitored at 678 nm, the excitation spectrum of Ba2LaSbO6:Mn4+ phosphor is observed in the range of 250-575 nm. Under the excitation of 380 nm, Ba2LaSbO6:Mn4+ phosphor exhibits strong deep-red emission in the range of 625-740 nm with emission peak at 678 nm due to the E-2 -> (4)A(2) transition of Mn4+ ion. The emission spectrum well matchs with the absorption spectrum of plants in the range of 625-740 nm. The temperature-dependent emission spectra illustrate the thermal stability of Ba2LaSbO6:Mn4+ phosphor and the thermal quenching mechanism is explained by the configuration coordinate of Mn4+ ion. The luminous mechanism of Ba2LaSbO6:Mn4+ phosphor is explained by the Tanabe-Sugano energy level diagram of Mn4+ ion. The experimental results show that the Ba2LaSbO6:Mn4+ deep-red-emitting phosphor would have potential application in plant growth LEDs.