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Far-red phosphors with higher thermal stability and exhibit excellent spectral compatibility with the far-red light phytochrome (P FR) absorption spectrum. They are currently a research hotspot and widely applied in plant growth lamps. In this study, we have prepared a Mn4+-activated Sr 2 ScNbO 6 far-red phosphor by using the high temperature solid phase method in air. The strongest excitation center of the Sr 2 ScNbO 6 : Mn4+ phosphor was located at 365 nm. Due to the 2E g →4A 2 g transition, this phosphor generates strong deep-red light at 703 nm, which significantly overlaps with the absorption spectrum of plant phytochrome P FR. The variable temperature photoluminescence (PL) emission spectra from 303 K to 503 K confirmed this phosphor possesses relatively good thermal stability. In addition, the concentration quenching effect and the thermal quenching mechanism are studied in detail. The results demonstrate that Sr 2 ScNbO 6 : 0.4 % Mn4+ phosphor provides a novel choice for the far-red phosphor required for short-day plant cultivation. • A double perovskite phosphor Sr 2 ScNbO 6 : Mn4+ was synthesized. • Sr 2 ScNbO 6 : Mn4+phosphor shows relatively good thermal stability, I 423 K /I 303 K ≈ 44 %. • The Mn4+ far-red emission matches well with the absorption spectral of P FR. • The materials show promising application in the field of short-day plant cultivation. [ABSTRACT FROM AUTHOR]

Red LEDs excited by blue light have a wide range of applications in plant growth due to their simple structure. The preparation of efficient red phosphors has attracted much attention from researchers. In this paper, Cs 2 NaGdCl 6 :Ho3+ Sb3+ phosphors were synthesized by the solvothermal method, which produced the characteristic emission of Ho3+ 5 F5→ 5 I8 at 655 nm under 460 nm excitation. The red light at 655 nm is further enhanced after the introduction of Sb3+, and the quantum efficiency can reach 39.85 %. The luminescence mechanism and energy transfer of Sb3+ and Ho3+ were further investigated. The produced phosphor was encapsulated with a 460 nm blue chip into an LED to realize red and blue dual emission, which meets the demand for blue and red light for plant growth. • A double perovskites phosphor Cs 2 NaGdCl 6 :Ho3+ Sb3+ was synthesized. • The emission spectrum excited by the blue light chip matches well with the plant absorption spectrum. • Synthesis of a halide double perovskites with good thermal stability. • The materials show promising application in the field of plant cultivation. [ABSTRACT FROM AUTHOR]

The crystal phase and energy band adjustment of halide perovskites have become the focus of research. Sb3+ doped lead-free indium-based perovskites A 2 InX 5 ·H 2 O:Sb3+ (A=Cs+, Rb+; X = Cl-, Br-) are synthesized at room temperature. Through changing the crystal phase structure, an intelligent anti-counterfeiting material is used to monitor water vapor and high temperature. Moreover, the Rb 2 InBr 5 ·H 2 O:Sb3+ achieves broadband near-infrared (NIR) emission with a high photoluminescence quantum efficiency (PLQY) of 54.3%. The NIR light-emitting diode shows that the device can effectively achieve NIR imaging. Theoretical calculations further clarified that the regular changes in luminescence originate from energy band modulation. This work provides a broader sight for the synthesis, luminescence mechanism and application of indium-based perovskite. • Indium-based perovskite with controllable luminescence properties was synthesized at room temperature. • The reversible change of crystal phase is used for smart anti-counterfeiting. • High-efficiency quantum yield of Rb 2 InBr 5 ·H 2 O:Sb3+ is used in near-infrared light-emitting diodes. • Theoretical calculation combined with experiments prove that broadband emission originate from band gap adjustment. [ABSTRACT FROM AUTHOR]