Dy³⁺@Mn⁴⁺co-doped Ca₁₄Ga_10−mAl_mZn₆O₃₅far-red emitting phosphors with high brightness and improved luminescence and energy transfer properties for plant growth LED lights

Abstract

A novel deep red phosphor Ca14Ga10−mAlmZn6O35:Dy3+,Mn4+(CGAZO:Dy3+,Mn4+) for plant growth LED lighting was successfully synthesizedviahigh-temperature solid-state reaction method and an effective energy transfer from Dy3+to Mn4+in the CGAZO host had been verified.

Enhancing photoluminescence properties of Mn4+‐activated Sr4−xBaxAl14O25 red phosphors for plant cultivation LEDs

“…When monitored at 655 nm, the excitation spectra have two broad band at 346 and 450 nm in range from 250 to 500 nm, respectively. Through Gaussian fitting peaks, the excitation band could be assigned to four peaks at 306 nm (32 680 cm −1 , O 2− –Mn 4+ ), 332 nm (30 120 cm −1 , O 2− –Mn 4+ ), 359 nm (27 855 cm −1 , 4 A 2 – 4 T 1 ), 430 nm (23 256 cm −1 , 4 A 2 – 2 T 2 ), and 461 nm (21 692 cm −1 , 4 A 2 – 4 T 2 ) . The results show that the phosphors are effectively excited through ultraviolet and blue chips.…”

“…Hence, the light of Mn 4+ emission generally matches the absorption spectrum of plant pigments . Furthermore, the Mn 4+ ion usually have a stably red emission owing to the strong ligand‐field stabilization energy when it occupies six‐coordinated sites . To our knowledge, the Mn 4+ ‐doped fluoride compound, such as A 2 BF 6 (A = Na, K, Cs; B = Si, Ge, Zr, Ti) host materials, is reported to exhibit an excellent luminescence property and physical and chemistry stability .…”

Tunable dual‐mode emission with excellent thermal stability in Ca4ZrGe3O12:Eu phosphors prepared in air for NUV‐LEDs

“…It is significant that luminescent intensity of CZGO:0.16Eu at 423 K (150°C) still maintains as much as 91.01% of that measured at room temperature upon 370 nm light irradiation. These results suggest that the as‐prepared phosphors display highly thermal stability, which is superior to that of most reported single‐phased phosphors for UV‐LEDs . The activation energy ( E a ) for thermal quenching of emission of CZGO:0.16Eu can be calculated via Arrhenian Equations,where I 0 and I(T) represent the luminescent intensities at room temperature and different temperatures, respectively.…”

Engineering cation vacancies to improve the luminescence properties of Ca14Al10Zn6O35: Mn4+ phosphors for LED plant lamp

“…Quantum efficiency is an important index to measure luminescence performance of phosphors. The relationship of internal quantum efficiency (IQE, η int ), external quantum efficiency (EQE, η ext ) of samples can be described as follows:where N inc , N abs and N em are the number of incident, absorbed, and emitted photons, respectively. A is the absorbance.…”

“…It is well known that most phosphors are prepared via high‐temperature solid‐state reaction method or hydrothermal method. However, the particle size of phosphors prepared via high‐temperature solid‐state reaction method is large, which may lead to component segregation and reduce the luminescence efficiency . The procedures of hydrothermal method are time‐consuming and costly .…”