Synthesis and optical properties of far-red dual perovskite Sr2InTaO6: Mn4+ phosphors for indoor plant lighting LED

Far-red light at 650–750 nm has a significant effect on plant development. It is of great significance to develop a kind of phosphor that can emit bright far-red light. In this paper, we demonstrate that Sr 2 InTaO 6 : Mn 4+ (abbreviated as SITO: Mn 4+ ), a phosphor emitting far-red light, can be used to fabricate light-emitting diodes (LEDs) for plant cultivation. SITO: Mn 4+ phosphor contains two unique excitation peaks at 325 and 368 nm that can be excited efficiently by near-ultraviolet light. The SITO: Mn 4+ phosphor generates far-red light with a peak wavelength of 695 nm at an excitation wavelength of 368 nm. The optimal Mn 4+ ions doping concentration was investigated. Furthermore, red LEDs were prepared through the combination of 365-nm chips and SITO: Mn 4+ phosphors and they emitted bright far-red light at 20–100 mA current. As a result, SITO: Mn 4+ phosphors can be used in the production of LEDs for plant cultivation illumination. • Sr 2 InTaO 6 : Mn 4+ far-red phosphors were synthesized. • The emission spectrum of the samples matched well with the absorption spectrum of the phytochromes. • The LEDs devices for plant cultivation were prepared with phosphor.