Synthesis,structural characterization,and photoluminescence properties of Eu3+‐doped Mg3‐xEux(BO3)2 phosphor

Eu³⁺‐doped Mg_3‐xEu_x(BO₃)₂ (x = 0.000, 0.005, 0.010, 0.020, 0.050, and 0.100) phosphors were synthesized for the first time by solution combustion synthesis method, which is a fast synthesis method for obtaining nano‐sized borate powders. The optimization of the synthesis conditions of phosphor materials was performed by TG/DTA method. These phosphors were characterized by XRD, FTIR, SEM‐EDX, and photoluminescence, PL analysis. The XRD analysis exhibited that all of the prepared ceramic compounds have been crystallized in orthorhombic structure with space group Pnnm. Also, the influence of europium dopant ions on unit cell parameters of host material was analyzed using Jana2006 program and the crystalline size was determined by Debye‐Scherrer's formula. The luminescence properties of all Eu³⁺‐doped samples were investigated by excitation and emission spectra. The excitation spectra of Mg_3‐xEu_x(BO₃)₂ phosphors show characteristic peak at 420 nm in addition to other characteristic peaks of Eu³⁺ under emission at 613 nm. The emission spectra of Eu³⁺‐doped samples indicated most intensive red emission band dominated at 630 nm belonging to ⁵D₀→⁷F₂ magnetic dipole transition. Furthermore, the optimum or quenching concentration of Eu³⁺ ion has been determined as x = 0.010 showed the maximum emission intensity when it was excited at 394 nm.     

Warm-white light performance of Dy3+, Eu3+: NaLa(WO4)2 phosphors excited with a 450-nm LED

Dy³⁺, Eu³⁺: NaLa(WO₄)₂ phosphors are successfully synthesized through the solid-state reaction technique. The phase-structure and morphology are measured via X-ray diffraction and energy dispersive spectrometry. The concentrations of Dy³⁺, Eu³⁺, La³⁺, and W⁶⁺ are measured via ICP. The absorption and excited spectra are presented, which indicate that a blue band ranging from 430 to 480 nm is suitable for excitation. Using a commercial blue LED with a wavelength of 450 nm as the excitation light source, emission spectra for samples with varying dopant concentration ratios of Dy³⁺ to Eu³⁺ are obtained, which show good tunable yellow and red emission. For the purpose of investigating white LED performance, CIE spectra and a white light photo are also presented. The results reveal that varying the dopant concentration ratio of Dy³⁺ to Eu³⁺ plays a key role in the warm-white performance. With increasing concentration of Eu³⁺, the correlated color temperature decreases from 4069 to 3172 K, which indicates good warm-white performance.     

Homogeneous Precipitation Synthesis and Low‐Voltage Cathodoluminescence of SnO2:Eu3+ Phosphors for Field Emission Displays

A reddish‐orange‐emitting SnO₂:Eu³⁺ phosphor for field emission displays (FEDs) was successfully synthesized via a homogeneous precipitation route using urea as a precipitant. The influences of the dopant concentration of Eu³⁺ and calcination temperature on optical properties were investigated. The low‐voltage field emission properties of the FED device prepared using the synthesized SnO₂:Eu³⁺ phosphors were reported. Under the UV light, SnO₂:Eu³⁺ phosphors display the strong orange–red emission peaked at 587, 591, and 597 nm due to the ⁵D₀→⁷F₁ magnetic dipole transition of Eu³⁺. The phosphor doped with 1.0 mol% Eu³⁺ possesses the highest photoluminescent (PL) intensity. Under the low‐voltage excitation of 300 V, the fabricated FED device exhibits the bright orange–red emission, high‐voltage brightness saturation, and high color purity, which has a potential application in low‐voltage full color FEDs.     

White light emission from novel host-sensitized single-phase Y2WO6: Ln3+ (Ln3+=Eu3+, Dy3+) phosphors

A series of Eu³⁺- or Dy³⁺-doped and Eu³⁺/Dy³⁺ co-doped Y₂WO₆ in pure phase was synthesized via high-temperature solid-state reaction. X-ray diffraction, diffuse reflection spectra, photoluminescence excitation and emission spectra, the CIE chromaticity coordinates and temperature-dependent emission spectra were exploited to investigate the phosphors. Upon UV excitation at 310 nm, efficient energy transfer from the host Y₂WO₆ to dopant ions in Eu³⁺ or Dy³⁺ single-doped samples was demonstrated and those phosphors were suitable for the UV LED excitation. The intense red emission was observed in Y₂WO₆: Eu³⁺, and blue and yellow ones were observed in Y₂WO₆: Dy³⁺. Concentration quenching in Y₂WO₆: Dy³⁺ phosphors could be attributed to the electric dipole-dipole interaction. In Eu³⁺/Dy³⁺ co-doped Y₂WO₆ phosphors energy transfer process only took place from the host to Eu³⁺/Dy³⁺ ions and warm white-light emission can be obtained by adjusting the dopant concentrations. The temperature-dependent luminescence indicated Eu³⁺/Dy³⁺ co-doped Y₂WO₆ was thermally stable. Our overall results suggested that Y₂WO₆: Ln³⁺ (Ln³⁺=Eu³⁺, Dy³⁺) as warm white-light emitting host-sensitized phosphor might be potentially applied in WLEDs.     

Luminescent Eu3+-doped transparent alumina ceramics with high hardness

The Eu³⁺-doped transparent aluminas were prepared by wet shaping technique followed by pressure-less sintering and hot isostatic pressing. The effect of dopant amount on microstructure, real in-line transmission (RIT), photoluminescence (PL) properties, hardness and fracture behaviour was studied. The RIT decreased with increasing amount of the dopant. The PL emission spectra of Al₂O₃:Eu³⁺ ceramics exhibited predominant red light emission with the highest intensity (under 394 nm excitation) for material containing 0.125 at.% of Eu³⁺ and colour coordinates (0.645, 0.355) comparable with commercial red phosphors. The doping resulted in hardness increase from 26.1 GPa for undoped alumina to 27.6 GPa for Eu-doped sample. The study of fracture surfaces showed predominantly intergranular crack propagation micro-mechanism.     

Microwave-assisted solvothermal preparation and photoluminescence properties of Y2O3:Eu phosphors

Europium doped yttrium oxide phosphors were synthesized by a rapid microwave-assisted solvothermal method. The microwave processing time for synthesizing the precursors of Y₂O₃:Eu³⁺ powders was as short as 5 min. After calcination at 600 °C, a well-crystallized pure phase of Y₂O₃:Eu³⁺ was obtained. The morphology of the precipitated powders was spherical and composed of nano-sized grains. As the microwave irradiation time was increased, the average particle size of the spherical powders increased, and the crystallinity of heat-treated powders was also enhanced. The synthesized powders retained the spherical morphology after heating treatments. An intense red emission at 611 nm was assigned to the ⁵D₀-⁷F₂ transition of Eu³⁺.     

Cyan-emitting Ba0.45Ca2.5La6(SiO4)6: 0.05 Eu2+ and Ba1.45Ca1.5La6(SiO4)6:0.05 Eu2+ solid-solution phosphors for white light-emitting diodes

Two cyan-emitting phosphors with different bandwidths were successfully synthesized through the high-temperature solid-state method in a reducing atmosphere. The crystal structures, morphologies, and luminescence properties of the as-prepared phosphors were investigated. The Rietveld refinements of the powder X-ray diffraction (XRD) data demonstrated the single phase of the samples, and two crystallographic sites of La³⁺ were observed in the crystal structure. Under the excitation of UV light, both Ba_0.45Ca_2.5La₆(SiO₄)₆: 0.05 Eu²⁺ and Ba_1.45Ca_1.5La₆(SiO₄)₆: 0.05 Eu²⁺ phosphors emitted cyan light due to the 4f⁶5 d¹→4f⁷ transitions of the Eu²⁺ ion. The emission spectra could be well fitted by two component Gaussian peaks corresponding to two different coordination environments of the Eu²⁺ ions. The temperature-dependent photoluminescence spectra show a large difference on the thermal stability between the two phosphors. The two phosphors exhibit effective absorption of near-UV light and their internal quantum efficiencies (IQEs) were calculated as 31.5% and 42.4% under 295 nm UV-light excitation. The experimental results indicate that the novel cyan phosphors might have potential applications in white light-emitting diodes (LEDs) based on the near-UV LED chip.     

Synthesis of nitride phosphor using entire oxides raw materials and their photoluminescence properties

Sr₂Si₅N₈:Eu²⁺ nitride phosphors application for light emitting diodes were synthesized for the first time using less‐expensive and air‐stable entire oxides raw materials, SrCO₃, SiO₂, and Eu₂O₃, through a carbothermal reduction and nitridation (CTRN) route. The reaction dynamic processes of the CTRN route and the phase components, photoluminescent properties, quantum efficiency as well as thermal stability for the resultant Sr₂Si₅N₈:Eu²⁺ phosphors were investigated in detail. High‐crystalline pure Sr₂Si₅N₈:Eu²⁺ red‐emitting phosphor with acceptant luminescent performances could be obtained through finely controlling addition amount of carbon reductant agent and carefully removing the residual carbon without oxidation damage. An economic route is outlined in this work for the synthesis of nitride phosphors using cost‐effective entire oxides raw materials, thereby driving the development and practical application of nitrides phosphors.     

Polymer-derived β-SiAlON:Eu2+ phosphors

A series of β-SiAlON:Eu²⁺ phosphors were synthesized from single-source precursors, perhydropolysilazane chemically modified with Al(OCH(CH₃)₂)₃, AlCl₃, and EuCl₂. The single-source precursors were converted to β-SiAlON:Eu²⁺ phosphors by pyrolysis under flowing N₂ or NH₃ at 1000°C, followed by heat treatment at 1800°C under an N₂ gas pressure at 980 kPa. By varying the molar ratio of the chemical modifiers, β-SiAlON:Eu²⁺ with the compositions close to the theoretical ones expressed as Si_6−zAl_zO_z−2yN_8−z+2y:yEu²⁺ were synthesized, where the z values and Eu²⁺ contents were controlled in the ranges of .44–.78 and .35–1.48 mol%, respectively. The polymer-derived β-SiAlON:Eu²⁺ phosphors exhibited green emission under excitation at 460 nm attributed to the 4f⁷–4f⁶(7f³)5d¹ transition of dopant Eu²⁺. High-angle annular dark-field-scanning transmission microscopy analysis confirmed that the doped-Eu²⁺ existed interstitially within the channels along the c axis of host β-SiAlON. Compared with the conventional powder metallurgy route, the polymer-derived ceramic route in this study offers some advantages in the grain growth of host β-SiAlON and photoluminescence properties in terms of green emission intensity under excitation at 460 nm, and the highest intensity was achieved for the polymer-derived β-SiAlON:Eu²⁺ with z = .64 and .37 mol% Eu²⁺.     

Combustion Synthesis of Ca2Si5N8: Eu2+ Phosphors and their Luminescent properties

A combustion synthesis method has been developed for synthesis of Eu²⁺‐doped Ca₂Si₅N₈ phosphor and its photoluminescence properties were investigated. Ca, Si, and Eu₂O₃ powders were used as the Ca, Si, and Eu sources. NaN₃ and NH₄Cl were found necessary to be added for the formation of the product phase and addition of Si₃N₄ was found to enhance the product yield. These powders were mixed and pressed into a compact, which was then wrapped up with an igniting agent (Mg + Fe₃O₄). The reactant compact was ignited by electrical heating under a N₂ pressure of 0.7 MPa. Effects of these experimental parameters on the product yield were investigated and a reaction mechanism was proposed. The synthesized Ca₂Si₅N₈: Eu²⁺ phosphor absorbs light in the region of 300–520 nm and shows a broad band emission in the region of 500–670 nm due to the 4f⁶5d¹ → 4f⁷ transition of Eu²⁺. Eu₂O₃ was found partially unreacted and a certain amount of oxygen is believed to be incorporated into the lattice of the product phase. The peak emission intensity (~93% of a commercially available phosphor, YAG:Ce³⁺v) and the peak emission wavelength (571–581 nm) were found to be lower and shorter, respectively, than that reported in the literature. These are considered to be mainly due to oxygen incorporation, which not only reduces nephelauxetic effect and crystal field splitting but also causes a lowering of internal quantum efficiency.     

Synthesis and luminescent properties of Sr4−xSi3O8Cl4: xEu3+ red phosphor by hydrothermal method

Sr_4‐xSi₃O₈Cl₄:xEu³⁺ (SSOC:Eu³⁺) phosphors were successfully synthesized by hydrothermal method. The crystallization of this phosphor was analyzed by means of X‐ray diffraction patterns. The size and morphology were recorded using SEM patterns of samples. And the PLE and PL spectra were characterized by a PL spectrophotometer. Excited by 394 nm UV light, the intense red emission is recognized in SSOC:Eu³⁺ phosphor and the main emission peak located at 620 nm. The influences of Eu³⁺ concentration, pH value of reaction solution, and charge compensator on PL spectra of SSOC:Eu³⁺ phosphors were investigated. The results revealed that this red phosphor had potential applications for white LEDs.     

Tunable white light and energy transfer of Dy3+ and Eu3+ doped Y2Mo4O15 phosphors

A series of Dy³⁺ or/and Eu³⁺ doped Y₂Mo₄O₁₅ phosphors were successfully synthesized at a low temperature of 600 °C via solid state reaction. The as-prepared phosphors were characterized by X-ray powder diffraction (XRD), scanning electronic microscope (SEM), photoluminescence (PL) excitation, emission spectra and PL decay curves. XRD results demonstrate that Y₂Mo₄O₁₅: Dy³⁺, Eu³⁺ has the monoclinic structure with the space group of p21/C(14). Under the excitation of ultraviolet (UV) or near-UV light, the Dy³⁺ and Eu³⁺ ions activated Y₂Mo₄O₁₅ phosphors exhibit their characteristic emissions in the blue, yellow and red regions. The emitting light color of the Y₂Mo₄O₁₅: 0.08Dy³⁺, yEu³⁺ phosphors can be adjusted by varying the concentration ratio of Dy³⁺ to Eu³⁺ ions and a white light is achieved when the doping concentration of Eu³⁺ is 5%. In addition, the energy transfer from Dy³⁺ to Eu³⁺ is also confirmed based on the luminescence spectra and decay curves.     

Synthesis and Photoluminescence of a New Chlorogermanate Phosphor Ca8Mg(GeO4)4Cl2:Eu2+

A new chlorogermanate compound Ca₈Mg(GeO₄)₄Cl₂ (CMGC) was synthesized via high‐temperature solid‐state reaction for the first time. The crystal structure of CMGC had been refined and determined from the XRD profiles by Rietveld refinement method, which belong to space group Fd‐3m with the lattice constants a = b = c = 15.1760(25) Å. Photoluminescence properties of CMGC:Eu²⁺ phosphors were investigated by absorption spectra, excitation, and emission spectra. The occupy situation and energy transfer were investigated by decay lifetimes and emission spectra under different excitation wavelengths. Thermal stability was also measured. The results show that the absorption spectra of CMGC:Eu²⁺ phosphors cover from 250 to 500 nm. Under 365 and 435 nm excitation, the emission spectra of CMGC:Eu²⁺ phosphors show blue‐green (centered at 425 and 510 nm) and green (centered at 510 nm) emission, respectively, which attributed to Eu²⁺ ions occupying different crystal sites. Our results indicated that CMGC:Eu²⁺ phosphors had a potential application use for white light‐emitting diodes.     

Synthesis of blue-emitting AlN:Eu2+ spherical phosphors by carbothermal reduction nitridation method

In this study, blue-emitting AlN:Eu²⁺ spherical phosphors were successfully synthesized for the first time by the carbothermal reduction nitridation (CRN) method, assisted with high nitrogen pressure, appropriate synthesis temperature, and the addition of CaF₂. The influence of typical experimental parameters, such as N₂ pressure, heating temperature, CaF₂ content and Eu²⁺ concentration on the morphologies and luminescence properties of AlN phosphors were comprehensively investigated. The formation mechanism of spherical morphology were significantly proffered, indicating that sufficient liquid Ca-aluminates during the AlN growth stage were essential for the spheroidization process under the action of surface tension. The synthesized AlN:Eu²⁺ spherical phosphors presented an intense blue emission band centered in the range of 427- 476 nm relative to the reaction temperature. The lifetime of AlN:Eu²⁺ phosphor was calculated to be around 1.89 μs. The temperature-dependent PL spectra suggested that the emission band did not shift until 225°C. In addition, the spectral analysis strongly suggested that the luminescence property of AlN:Eu²⁺ phosphors was significantly enhanced by the large particle size, spherical morphology, reduced impurity content, and appropriate Eu²⁺ concentration.     

Preparation of Sr1−xCaxLiAl3N4:Eu2+ Solid Solutions and Their Photoluminescence Properties

A series of quaternary nitride solid solutions with a general formula of Sr_1?xCa_xLiAl₃N₄:0.5%Eu²⁺ was synthesized by a solid‐state reaction method. The experimental results showed that a proper amount of Ca‐doping can improve the crystallinity and the photoluminescence properties of the produced phosphors. Rietveld refinement showed that the volume of the unit cell shrank with the increase of Ca substitution for Sr, which resulted in a red shift of the emission spectra from 654 to 665 nm under blue excitation at 475 nm. Rietveld refinement and CASTPE calculations suggested that Ca²⁺ ions prefer to occupy the smaller Sr(I) sites in the crystal lattice, which increases the amount of Eu²⁺ ions in Sr(II) sites and enables the tuning of the chromaticity coordinates of the obtained phosphors. The thermal stability of the produced phosphors is better than that of commercial Sr₂Si₅N₈:Eu²⁺ phosphor. The experimental results qualify the solid‐solution Sr_1?xCa_xLiAl₃N₄:0.5%Eu²⁺ for consideration as a potential candidate for application in white LEDs.     

Synthesis and photoluminescence properties of the high-brightness Eu3+-doped Sr3Y(PO4)3 red phosphors

A series of red-emitting phosphors Eu³⁺-doped Sr₃Y(PO₄)₃ have been successfully synthesized by conventional solid-state reaction, and its photoluminescence properties have been investigated. The excitation spectra reveal strong excitation bands at 392 nm, which match well with the popular emissions from near-UV light-emitting diode chips. The emission spectra of Sr₃Y(PO₄)₃:Eu³⁺ phosphors exhibit peaks associated with the ⁵D₀ → ⁷F_J (J = 0, 1, 2, 3, 4) transitions of Eu³⁺ and have dominating emission peak at 612 nm under 392 nm excitation. The integral intensity of the emission spectra of Sr₃Y_0.94(PO₄)₃:0.06Eu³⁺ phosphors excited at 392 nm is about 3.4 times higher than that of Y₂O₃:Eu³⁺ commercial red phosphor. The Commission Internationale de l’Eclairage chromaticity coordinates, the quantum efficiencies and decay times of the phosphors excited under 392 nm are also investigated. The experimental results indicate that the Eu³⁺-doped Sr₃Y(PO₄)₃ phosphors are promising red-emitting phosphors pumped by near-UV light.     

Synthesis and photoluminescence properties of CaGd2(MoO4)4:Eu3+ red phosphors

The novel red-emitting Eu³⁺ ions activated CaGd₂(MoO₄)₄ phosphors were prepared by a citrate sol–gel method. The X-ray diffraction patterns confirmed their tetragonal structure when the samples were annealed above 600 °C. The photoluminescence excitation spectra of CaGd₂(MoO₄)₄:Eu³⁺ phosphors exhibited the charge transfer band (CTB) and intense f–f transitions of Eu³⁺ ion. The optimized annealing temperature and Eu³⁺ ion concentration were analyzed for CaGd₂(MoO₄)₄:Eu³⁺ phosphors based on the dominant red (⁵D₀→⁷F₂) emission intensity under NUV (394 nm) excitation. All decay curves were well fitted by the single exponential function. These luminescent powders are expected to find potential applications such as WLEDs and optical display systems.     

New single‐component multicolor emission Na1−xAl1+2xSi1−2xO4:xBi3+/Eu3+ phosphors via energy transfer

A series of emission‐tunable Na_1?xAl_1+2xSi_1?2xO₄:xBi³⁺/Eu³⁺ phosphors were synthesized via high temperature solid‐state reaction method. The luminescence properties, energy transfer from Bi³⁺ to Eu³⁺ ions, color tuning, thermal stability and quantum efficiency were systematically investigated. Especially, in the host, a certain amount of Si⁴⁺ were replaced by Al³⁺ in order to remedy the charge compensating defect, so that, the emission intensity had been improved. The results of Rietveld refinements, the analysis of SEM mapping and the fourier transform infrared (FT‐IR) indicated that this charge balance strategy was an effective method. Meanwhile, the energy transfer from Bi³⁺ to Eu³⁺ can be inferred and confirmed and the mechanisms were demonstrated to quadrupole–quadrupole interaction. The emission hue can be tuned from blue to pink, and finally to orange red light by properly varying the ratio of Bi³⁺ and Eu³⁺. Importantly, when the temperature was raised to 150°C, the integrated emission intensity was 71.20% of the initial value for NAS:1%Bi³⁺,2%Eu³⁺ samples indicating that these phosphors had excellent thermal stability and stable color (no emission shift). All these properties indicate that the developed phosphors may be potentially used as single‐component color‐tunable‐emitting phosphors for UV light‐emitting diodes.     

Synthesis and photoluminescence enhancement of Ca3Sr3(VO4)4:Eu3+ red phosphors by co-doping with La3+

In this study, a series of red-emitting Ca₃Sr₃(VO₄)₄:Eu³⁺ phosphors co-doped with La³⁺ was prepared using the combustion method. The microstructures, morphologies, and photoluminescence properties of the phosphors were investigated. All Ca₃Sr₃(VO₄)₄:Eu³⁺, La³⁺ samples synthesized at temperatures greater than 700 ℃ exhibited the same standard rhombohedral structure of Ca₃Sr₃(VO₄)₄. Furthermore, the Ca₃Sr₃(VO₄)₄:Eu³⁺, La³⁺ phosphor was effectively excited by near-ultraviolet light of 393 nm and blue light of 464 nm. The strong excitation peak at 464 nm corresponded to the ⁷F₀→⁵D₂ electron transition of Eu³⁺. The strong emission peak observed at 619 nm corresponded to the ⁵D₀→⁷F₂ electron transition of Eu³⁺. Co-doping with La³⁺ significantly improved the emission intensity of Ca₃Sr₃(VO₄)₄:Eu³⁺ red phosphors. The optimum luminescence of the phosphor was observed at Eu³⁺ and La³⁺ concentrations of 5% and 6%, respectively. Moreover, co-doping with La³⁺ also improved the fluorescence lifetime and thermal stability of the Ca₃Sr₃(VO₄)₄:Eu³⁺ phosphor. The CIE chromaticity coordinate of Ca₃Sr₃(VO₄)₄:0.05Eu³⁺, 0.06La³⁺ was closer to the NTSC standard for red phosphors than those of other commercial phosphors; moreover, it had greater color purity than that of all the samples tested. The red emission intensity of Ca₃Sr₃(VO₄)₄:0.05Eu³⁺, 0.06La³⁺ at 619 nm was ~1.53 times that of Ca₃Sr₃(VO₄)₄:0.05Eu³⁺ and 2.63 times that of SrS:Eu²⁺. The introduction of charge compensators could further increase the emission intensity of Ca₃Sr₃(VO₄)₄:Eu³⁺, La³⁺ red phosphors. The phosphors synthesized herein are promising red-emitting phosphors for applications in white light-emitting diodes under irradiation by blue chips.     

A novel scheelite-type LiCaGd(WO4)3:Eu3+ red phosphors with prominent thermal stability and high quantum efficiency

A series of LiCaGd(WO4)3 : xEu³⁺ (0 ≤ x ≤ 1.0) red phosphors with tetragonal scheelite structure were synthesized via the conventional solid-state reaction. Their crystal structure, photoluminescence excitation (PLE), and photoluminescence (PL) spectra, thermal stability and quantum efficiency were investigated. The phosphors exhibit a typical red light upon 395 nm near ultraviolet excitation, and the strongest emission peak at 617 nm is dominated by the ⁵D₀→⁷F₂ transition of Eu³⁺ ions. The PL intensity of the phosphors gradually increases with the increase of Eu³⁺ doping concentration, and the concentration quenching phenomenon is hardly observed. The quantum efficiency and the color purity of the phosphor reach maximum values of about 94.2 and 96.6% at x = 1.0, respectively. More importantly, LiCaGd(WO₄)₃:xEu³⁺ phosphors have prominent thermal stability. The temperature-dependent PL intensity of the phosphors at 423 K is only reduced to 89.1% of the PL intensity at 303 K, which is superior to that of commercial red phosphors Y₂O₃:Eu³⁺. Finally, LiCaGd(WO₄)₃:Eu³⁺ phosphor is packaged with near ultraviolet InGaN chips to fabricate white light emitting diodes, which has a low color temperature (CCT = 4622 K) and a high color rendering index (CRI= 89.6).