A new double perovskite CaY0.5Ta0.5O3:Mn4+ deep-red phosphor: Synthesis, optical properties, and potential applications in plant-growth LEDs

Ultrahighly Efficient Narrowband Red Luminescence of Uniquely Distorted Mn4+ Octahedron in the Feldspar‐Type LED Phosphor

“…The calculated ΔE values of the CASO:0.01Mn 4+ (34 × 10 −3 ) and CASO:0.01Mn 4+ , 0.05Mg 2+ (31 × 10 −3 ) thus exhibit favorable color stabilities with slight chromaticity shifts, which are not only competitive with the commercial K 2 SiF 6 :Mn 4+ (ΔE = 34×10 −3 ) phosphor as well as K 2 SiF 6 :Mn 4+ @K 2 SiF 6 (ΔE = 27 × 10 −3 ) and CsMoO 2 F 3 :Mn 4+ (ΔE = 34 × 10 −3 ) phosphors but surpass some other red-emitting phosphors such as CaAlSiN 3 :Eu 2+ (ΔE = 44 × 10 −3 ) and CaY 0.5 Ta 0.5 O 3 :Mn 4+ (ΔE = 138 × 10 −3 ). [46,56] These results confirm the potential of our feldspar-type phosphors for application in illumination-grade warm WLEDs.…”

“…[55] As shown in Table S3 and Figure S12 (Supporting Information), the chromaticity coordinates of the CASO:0.01Mn 4+ /0.01Mn 4+ , 0.05Mg 2+ phosphors calculated from the respective temperature-dependent PL spectra vary slightly from (0.693, 0.307)/(0.719, 0.281) to (0.678, 0.324)/(0.698, 0.302) with an increase in the heating temperature. The chromaticity shifts (ΔE) of both phosphors were calculated using the following equation [46] ΔE =…”

High Water Resistance and Luminescent Thermal Stability of LiyNa(2–y)SiF6: Mn4+ Red-Emitting Phosphor Induced by Codoping of Li+

“…In addition to sample (i), Na 2 SiF 6 :Mn 4+ ,Li + (Li y Na (2– y ) SiF 6 :Mn 4+ ) synthesized in our previous work using K 2 MnF 6 as the starting material via the cation-exchange method also did not exhibit the NTQ effect. Furthermore, there is no NTQ effect for most of Mn 4+ -doped phosphors. ,,, For example, K 2 NaAlF 6 :Mn 4+ , Cs 2 KGaF 6 :Mn 4+ , CaY 0.5 Ta 0.5 O 3 : Mn 4+ , and K 3 SiF 7 :Mn 4+ are some of the representatives.…”

“…In order to manufacture white light-emitting diodes (WLEDs) with low correlated color temperature (CCT < 4500 K) and good color rendering index (CRI, Ra > 80), − red-emitting phosphors are an essential component. Mn 4+ -activated fluorides, for example, A 2 XF 6 :Mn 4+ − and A 3 YF 6 :Mn 4+ (A = NH 4 , Cs, K, Na; X = Ti, Zr, Si, Ge; Y = Ga, Al) − are such phosphors. Among them, Mn 4+ -doped potassium fluorosilicate is widely used in commercial applications because of its high QY and narrowband emission .…”

Machine learning the peak emission wavelength of Mn4+-activated inorganic phosphors

“…Recently, transition metal Mn 4+ activated inorganic phosphors showing very narrow red emission have attracted tremendous attention owing not only to fundamental interest, but also to application prospects in indoor lighting and agriculture, bio-medical, data communication and signal transmissions, and so forth. 1–15 Mn 4+ ions, acting as an activator, show broad absorption bands in the ultraviolet and blue region (200–600 nm) resulting from the 4 A 2g → 4 T 1g , 2 T 2g , 4 T 2g transitions and emit red light (600–780 nm) owing to the 2 E g → 4 A 2g transitions, while it situates in a host material with octahedral sites. 16,17 Their emission behavior is heavily affected by their local chemical coordination, host matrix composition, and their inherent crystallographic distortions, activator concentrations, and the energy transfer mechanisms involved.…”