Novel deep‐red‐emitting double‐perovskite type Ca₂ScNbO₆:Mn⁴⁺ phosphor: Structure, spectral study, and improvement by NaF flux

Abstract

A novel deep‐red‐emitting phosphor Ca2ScNbO6:Mn4+ is prepared via a high‐temperature solid‐state reaction and its luminescent properties are systematically investigated. The results show that Mn4+‐activated Ca2ScNbO6 phosphors have broad absorption in ultraviolet region, and show bright deep‐red emission at 692 nm. The optimal doping concentration, crystal‐field strength, internal quantum efficiency, and mechanism of concentration and thermal quenching effects are discussed in detail. Moreover, NaF flux is screened out to improve both luminescent intensity and morphology of the phosphor. Finally, a red light‐emitting diode (LED) lamp is fabricated with as‐prepared Ca2ScNbO6:Mn4+ phosphors and a 365 nm LED chip. The electroluminescence spectra show a good overlapping with phytochrome PR and PFR absorbance. The results provided the as‐synthesized Ca2ScNbO6:Mn4+ phosphors a great potential in plant growth lighting.

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

“…The linear fitting of ln­( I 0 / I T – 1) versus 1/ kT was shown in the inset of Figure c and the Δ E value was obtained for Δ E = 0.35 eV, which is a reasonable result compared with other oxide phosphor (e.g., Δ E [Sr 2 YSbO 6 :Mn 4+ ] = 0.29 eV, Δ E [Ca 2 ScNbO 6 :Mn 4+ ] = 0.42 eV, Δ E [LaTiSbO 6 :Mn 4+ ] = 0.51 eV, etc. ). − …”

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.…”

“…It is noted that broadened emission bands are widely observed in Mn 4+ . [61][62][63][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.…”