Highly efficient and thermally stable CaYMgSbO6:Mn4+ double perovskite red phosphor for indoor plant growth

Abstract

A novel Mn4+ activated CaYMgSbO6 (CYMS) far-red phosphor was synthesized by high temperature solid state reaction. The sample was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), luminescence spectra, ultraviolet–visible spectra, emission-temperature relationship and internal quantum efficiency (IQE). It is found that CYMS:Mn4+ phosphor has a strong broad excitation band in the range of 200–550 nm. The sample can be excited by ultraviolet and blue light. There is a wide emission band centered at 688 nm between 600 and 760 nm. The optimum doping concentration of Mn4+ is approximately 0.2 mol%. In addition, all the Commission Internationale de L’Eclairage (CIE) chromaticity coordinates of CYMS:0.002Mn4+ located in the far-red region. The concentration quenching mechanism is the dipole-quadrupole interaction of Mn4+ activator. The sample has excellent thermal stability (I423K/I298K = 53.2%). Importantly, the CYMS:0.002 Mn4+ phosphor has an IQE up to 51.5%. Finally, a 365 nm ultraviolet light emitting diode chip combined with CYMS:0.002 Mn4+ phosphor was used to fabricate the LED device. All the results indicated that CYMS:Mn4+ phosphors have potential applications in indoor plant cultivation.