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A green phosphor Sr2ZnGe2O7:Mn2+ with a melilite structure was prepared using a high‐temperature solid‐state reaction. When the 535 nm emission was monitored, the excitation spectrum of the Sr2ZnGe2O7:Mn2+ was found to contain two excitation bands in the ultraviolet (UV) region. When excited by UV light, the sample shows bright green emission at 535 nm, which corresponds to the distinctive transition of Mn2+ (4T1→6A1). Moreover, the quantum efficiency of Sr2ZnGe2O7:Mn2+ could reach 67.6%. Finally, a high‐performance white‐light‐emitting diode (WLED) with a low correlated colour temperature of 4632 K and a high colour rendering index (CRI) of 92.3 were packaged by coating commercial blue and red phosphors with an optimized Sr2ZnGe2O7:Mn2+ sample on a 310 nm UV chip. This indicated that Sr2ZnGe2O7:Mn2+ has the potential application as a green component in the WLED lighting field. [ABSTRACT FROM AUTHOR]

In this work, a novel red-emitting oxyfluoride phosphor Na2NbOF5:Mn4+ with an ultra-intense zero-phonon line (ZPL) was successfully synthesized by hydrothermal method. The phase composition and luminescent properties of Na2NbOF5:Mn4+ were studied in detail. The photoluminescence excitation spectrum contains two intense excitation bands centered at 369 and 470 nm, which match well with commercial UV and blue light-emitting diode (LED) chips. When excited by 470 nm blue light, Na2NbOF5:Mn4+ exhibits red light emission dominated by ZPL. Notably, the color purity of the Na2NbOF5:Mn4+ red phosphor can reach 99.9%. Meanwhile, the Na2NbOF5:Mn4+ phosphor has a shorter fluorescence decay time than commercial K2SiF6:Mn4+, which is conducive to fast switching of images in display applications. Profiting from the intense ZPL, white light-emitting diode (WLED) with high color rendering index of Ra = 86.2 and low correlated color temperature of Tc = 3133 K is realized using yellow YAG:Ce3+ and red Na2NbOF5:Mn4+ phosphor. The WLED fabricated using CsPbBr3 quantum dots (QDs) and red Na2NbOF5:Mn4+ phosphor shows a wide color gamut of 127.56% NTSC (National Television Standard Committee). The results show that red-emitting Na2NbOF5:Mn4+ phosphor has potential application prospects in WLED lighting and display backlight. [ABSTRACT FROM AUTHOR]

A green phosphor Sr 2 ZnGe 2 O 7 :Mn 2+ with a melilite structure was prepared using a high-temperature solid-state reaction. When the 535 nm emission was monitored, the excitation spectrum of the Sr 2 ZnGe 2 O 7 :Mn 2+ was found to contain two excitation bands in the ultraviolet (UV) region. When excited by UV light, the sample shows bright green emission at 535 nm, which corresponds to the distinctive transition of Mn 2+ ( 4 T 1 → 6 A 1 ). Moreover, the quantum efficiency of Sr 2 ZnGe 2 O 7 :Mn 2+ could reach 67.6%. Finally, a high-performance white-light-emitting diode (WLED) with a low correlated colour temperature of 4632 K and a high colour rendering index (CRI) of 92.3 were packaged by coating commercial blue and red phosphors with an optimized Sr 2 ZnGe 2 O 7 :Mn 2+ sample on a 310 nm UV chip. This indicated that Sr 2 ZnGe 2 O 7 :Mn 2+ has the potential application as a green component in the WLED lighting field., (© 2023 John Wiley & Sons Ltd.)