Deep‐red‐emitting Ca₂ScSbO₆:Mn⁴⁺ phosphors with a double perovskite structure: Synthesis, characterization and potential in plant growth lighting

Abstract

Mn 4+ -activated double-perovskite type Ca 2 ScSbO 6 (CSS) phosphors were synthesized via a high-temperature solid-state reaction. The phase purity and crystal structure of obtained samples were investigated by powder X-ray diffraction (XRD). The successful incorporation of Mn 4+ ions into CSS lattice was confirmed by the combination of energy-dispersive X-ray spectra (EDX) and X-ray photoelectron spectra (XPS) results. The luminescent properties of the CSS phosphors, including the photoluminescence (PL) and PL excitation (PLE) spectra, commission international de l'clairage (CIE) chromaticity coordinates, fluorescence decay curves, quantum yields and temperature-dependent PL spectra, were investigated in detail. Under 310-nm excitation, the optimized CSS:0.3%Mn 4+ phosphor exhibited bright deep-red emission covering a narrow band from 640 nm to 720 nm, which overlaps with the absorbance of phytochromes. The Racah parameters B, C, and local crystal strength Dq were calculated to be 870, 2703, and 1984 cm -1 , respectively. Particularly, the emission intensity of CSS:0.3%Mn 4+ still remained 61.4% at 423 K compared with that at room temperature. Therefore, all these outstanding luminescent properties provided the as-synthesized phosphors a great potential in plant growth lighting.

Fundamental luminescence properties of Mn4+ activated Ca14Al10Zn6O35 phosphor

“…It is noted that broadened emission bands are widely observed in Mn 4+ -doped double perovskites with multiple octahedral sites (such as [AlO 6 ]/[NbO 6 ] in Ca 2 AlNbO 6 , [ScO 6 ]/[SbO 6 ] in Ca 2 ScSbO 6 , and [MgO 6 ]/[WO 6 ] in NaLaMgWO 6 ). 61–64 Therefore, the occupation of Mn 4+ ions in double or multiple symmetry sites (luminescence centers) should be taken into consideration. As shown in Fig.…”

Tunable Spinel Structure Phosphors: Dynamic Change in Near‐Infrared Windows and Their Applications

“…Phosphor-converted LED (pc-LED) in agriculture has developed fast recently because the hybrid emission from blue LED chips and red/NIR phosphor can match the absorption of chlorophyll and phytochrome for plant growth promotion and blooming, respectively. [105][106][107][108][109] For different purposes, the emission wavelength of phosphors needs to be tuned to fit the pigment's absorption. In Figure 14, the absorption of chlorophyll a and b possessed significant peaks around 650-670 nm, which is related to photosynthetic reaction centers.…”

Mn4+-Activated Double-Perovskite-Type Sr2LuNbO6 Multifunctional Phosphor for Optical Probing and Lighting

“…To achieve the multifunctionalization of Mn 4+ , the selection of host materials is crucial as it directly determines the luminescent characteristics, emission efficiency, responsiveness to external fields, physical and chemical stability, and other properties of the synthesized phosphors, which is a prerequisite for achieving their multifunctional application value. Among numerous materials, oxides with a double perovskite structure A 2 B′B″O 6 are considered an ideal host. − The structure provides abundant octahedral sites to accommodate Mn 4+ ions, offering a suitable crystal field environment and excellent chemical stability for Mn 4+ luminescence.…”