Warm White Light Emission Research Articles

Warm white light emission, thermochromic property and long persistent luminescence derived from multi-sites of Eu2+/Eu3+ in host lattice

Making a further insight into the structure-property relation of luminescent materials is not only in theory but also with reference value in developing more practical materials in this field. This paper reports a new luminescent material K5Y(P2O7)2:Eu (KYP:Eu), in which the Eu2+ dopants may occupy K+ or Y3+ sites. As a result, a warm white emission covering a wide range of 430–720 nm is generated at room temperature, in which the bands at 430–520 nm are due to Eu2+ in K+ sites and the bands at 530–720 nm are attributed to Eu2+ in Y3+ sites. Owing to the difference of Eu2+ sensitivity at different sites, or the effects of co-existence of Eu2+ and Eu3+, a position interchange between Eu2+ and Eu3+ happens at very low temperature (<175 K), which leads to the emission colors turning from dark blue, through blue-white and finally to white with increasing temperature from 10 to 450 K. Besides, the phosphor KYP:Eu shows long-persistent luminescence (LPL), which could be improved after doping 0.5% Pr3+. These results suggest that prepared phosphor has utilization potentiality in multiple fields of white light-emitting diodes (WLEDs), optical thermometry and persistent luminescence.

Desired warm white light emission from a highly photostable and single-component Gd2TiO5:Dy3+/Eu3+ nanophosphors for indoor illuminations

At present, phosphor-converted white light-emitting diodes (pc-WLEDs), developed by combining an ultraviolet (UV)/near-UV (NUV) LED and a single-component white emitting phosphor, have attracted significant interest and are emerged as the new-generation green light sources. Herein, we report a highly photostable and novel Gd2TiO5 (GT):Dy3+/Eu3+ nanophosphors as single-component white emitting phosphors by sol-gel route. Based on X-ray diffraction pattern, Rietveld refinement is performed to authorize the orthorhombic phase of the GT nanophosphors. The nanosized particles with nearly spherical morphology is perceived after annealing at 1100 ℃. The Dy3+ and Eu3+ ions individually-doped GT nanophosphors exhibited pleasant white and reddish-orange emissions by monitoring with their respective excitation wavelengths. Tunable white light emission is achieved by co-doping the various concentrations of Eu3+ ions to the optimized GT:1.5Dy3+ nanophosphors under both UV (270 nm) and NUV (362 nm) excitations. The energy transfer probability is discussed and the energy transfer efficiency from Dy3+ to Eu3+ ions is calculated from the luminescence decay profiles. On rising the Eu3+ ions content from 0.25 to 6 mol%, the energy transfer efficiency is increased from 14% to 73% for co-doped GT nanophosphors. Besides, the optimized samples of Dy3+ and Eu3+ ions individually-doped and co-doped GT samples exhibited high quantum efficiencies and increased photostability. Thus, the acquired results signifying that these GT:Dy3+/Eu3+ nanophosphors can serve as potential single-component white emitting phosphors for UV and/or NUV-based pc-WLEDs.

Optical characteristics and energy transfer between Eu3+ and Dy3+ in Na2CaSiO4:Dy3+, Eu3+ white-emitting phosphor

A new type of white-emitting phosphor Na2CaSiO4:Dy3+, Eu3+ was synthesized through the sol-gel method, and the influences of doping concentration and synthesis temperature on photoluminescence properties and crystal phase were systematically studied. The X-ray diffraction results manifested that the structures of all Na2CaSiO4:Dy3+, Eu3+ phosphors prepared at the temperatures above 1100 ℃ and Na2CaSiO4 are of the same type. Under the excitation of 349 nm, the as-prepared Na2CaSiO4:Dy3+ phosphors showed a blue emission peak at 487 nm and a yellow emission peak at 579 nm attributed to the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions of Dy3+ ions. Meanwhile, a white light emission was reached by the combination of the obtained blue and yellow components. By co-doping Eu3+ ions, a characteristic emission peak appeared in red region (617 nm) and it was ascribed to the characteristic 5D0→7F2 transition of Eu3+. The warm white light emission (CCT = 2728 K) was realized with the 0.03Dy3+, 0.02Eu3+ co-doped Na2CaSiO4 phosphor. All results confirmed that the Na2CaSiO4:Dy3+, Eu3+ phosphor with excellent white emission has a potential application in the field of white light emitting diodes.

Full-visible-spectrum emission with high color rendering index and low correlated color temperature enabled by a single-phased phosphor of α-Sr2V1.98P0.02O7: 0.5% Eu3+

A single-phased warm white phosphor of α-Sr2V1.98P0.02O7: 0.5 % Eu3+ with low correlated color temperature (CCT) and high color rendering index (CRI) was synthesized by high temperature solid phase method. By changing the ratio of PO43−/VO43−, the emission intensity of VO43− and the energy transfer efficiency of VO43−→Eu3+ can be effectively tuned, and the full-spectrum warm white light emission of phosphors in the range of 400−700 nm can be realized. Moreover, the temperature-dependent emission spectra and thermal quenching properties were investigated in detail. On this basis, the WLED prototype devices were packaged with the synthesized phosphors α-Sr2V1.98P0.02O7: 0.5 % Eu3+ and 365 nm near-ultraviolet (NUV) chips and high-quality warm white light emission with CCT = 3188 K and CRI Ra = 93.5 were achieved. These findings provide new insights into exploring single-phased white phosphors for NUV-pumped warm w-LEDs with high CRI property and low CCT value.

Realizing Tunable White Light Emission in Lead-Free Indium(III) Bromine Hybrid Single Crystals through Antimony(III) Cation Doping.

Low-dimensional metal halide hybrids (OIMHs) have recently been explored as single-component white-light emitters for use in solid-state lighting. However, it still remains challenging to realize tunable white-light emission in lead-free zero-dimensional (0D) hybrid system. Here, a combination strategy has been proposed through doping Sb3+ enabling and balancing multiple emission centers toward the multiband warm white light. We first synthesized a new lead-free 0D (C8NH12)6InBr9·H2O single crystal, in which isolated [InBr6]3- octahedral units are separated by large organic cations [C8NH12]+. (C8NH12)6InBr9·H2O exhibits dual-band emissions with one intense cyan emission and a weak red emission tail. The low-energy ultrabroadband red emission tail can be greatly enhanced by the Sb3+ doping. Experimental data and first-principles calculations reveal that the original dominant cyan emission is originated from the organic cations [C8NH12]+ and that the broadband red emission is ascribed to self-trapped excitons in [In(Sb)Br6]3-. When the Sb concentration is 0.1%, a single-component warm white-light emission with a photoluminescence quantum efficiency of 23.36%, correlated color temperature of 3347 K, and a color rendering index up to 84 can be achieved. This work represents a significant step toward the realization of single-component white-light emissions in environmental-friendly, high-performance 0D metal halide light-emitting materials.

Novel thermally robust warm white light emitting phosphor Ca18Li3Y(PO4)14:Dy3+: Synthesis, crystal structure and luminescence property investigation

To explore novel single phase warm white light emitting phosphor, a series of phosphate phosphors Ca18Li3Y(PO4)14:Dy3+ were prepared. The phase purity, crystal structure, morphology and element component were confirmed by XRD Rietveld structure refinement, SEM and EDS analysis. The luminescence process of Ca18Li3Y(PO4)14:Dy3+ were systematically studied by photoluminescence spectroscopy and decay curves. The results indicated Ca18Li3Y(PO4)14:Dy3+ phosphors had strong excitation from 300 nm to 420 nm. Under the excitation of 350 nm, warm white light emission was achieved with the CIE color coordinates of (0.399, 0.448) and low CCT of ~ 3992 K. The concentration quenching mechanism and quantum efficiency of Dy3+ in Ca18Li3Y(PO4)14:Dy3+ were calculated and discussed in detail. The thermal quenching behavior revealed that Ca18Li3Y(PO4)14:Dy3+ had excellent thermal stability with stable color rendition. The thermal activation energy was finally calculated. All the results indicated the potential application of Ca18Li3Y(PO4)14:Dy3+ white light emission phosphor to be used in solid state lighting.

Eu3+-activated Ca2YTaO6 double-perovskite compound: A novel highly efficient red-emitting phosphor for near-UV-excited warm w-LEDs

In this work, novel Eu3+ ions activated red emitting Ca2YTaO6 (CYT) phosphors have been prepared via a high-temperature solid-state reaction approach. Their crystal structure and photoluminescence properties were investigated by X-ray diffraction (XRD) patterns, photoluminescence excitation and emission spectra, and decay lifetimes. XRD Rietveld refinement results revealed that the CYT:Eu3+ phosphors crystallized in the monoclinic structure with the space group of P21/n and lattice parameters of a = 5.5989 Å, b = 5.8449 Å, c = 8.1016 Å, α = γ = 90°, β = 89.8799°, and V = 264.625 Å3. The CYT:xEu3+ phosphors could be excited by near-ultraviolet light around 396 nm, and they showed bright narrowband red emissions peaking at 590, 614, 656, and 703 nm due to the 5D0→7FJ (J = 1–4) transitions of Eu3+ ions. The 614 nm red emission corresponding to the 5D0→7F2 transition was dominant in the emission spectra, indicating that the Eu3+ ions occupied non-centrosymmetric sites. The critical quenching concentration in CYT:xEu3+ phosphors was 50 mol%, and the optimal CYT:0.5Eu3+ phosphors showed PL intensity as great as 4.2 times higher than the commercial red phosphors Y2O3:Eu3+. CIE chromaticity coordinates of CYT:0.5Eu3+ phosphors were (0.6678, 0.3319), and the color purity reached up to 97.4%. The nonradiative energy transfer between the Eu3+ ions in the CYT host was attributable to dipole-dipole interaction, and the critical distance was roughly 7.97 Å. A warm white light-emitting diode (w-LED) based on the combination of a 395 nm LED chip with a blend of commercial BaMgAl10O17:Eu2+blue phosphors and commercial (Ba,Sr)2SiO4:Eu2+ green phosphors and as-prepared CYT:0.5Eu3+ red phosphors was fabricated, which gave warm white-light emission with excellent CIE color coordinates of (0.3833, 0.3859), low correlated color temperature of 3991 K, high color rendering index of 92.1, and good luminous efficacy of 21.76 lm/W.

A novel Mn4+-activated Li3CsGe8O18 red phosphor and cation substitution induced photoluminescence improvement

Nowadays, non-rare-earth Mn4+-activated red phosphors have emerged for improvement of the lighting quality of phosphor-converted white light-emitting-diodes (pc-WLED), owing to the low cost and the admirable luminescence properties. In this work, a novel narrow-band red-emitting Li3CsGe8O18:Mn4+ phosphor was synthetized based on the component substitution from Li3RbGe8O18, which exhibits the red luminescence centered at 668 nm upon 466 nm excitation. By further designing [Cs+-Rb+] cation substitution, the photoluminescence intensity and luminescence efficiency are obviously improved. The photoluminescence intensity enhanced 1.75 times than Li3RbGe8O18:Mn4+ phosphor, while the corresponding internal quantum efficiency (IQE) increased by 1.57 times. According to the Rietveld refinement results, the corresponding mechanism of luminescence enhancement is attributed to the smaller distortion degree of the [Ge(1)O6] octahedron. The pc-WLED device is fabricated by the optimal Li3Cs0.5Rb0.5Ge8O18:1%Mn4+ red phosphor, yellow phosphor with Y3Al5O12:Ce3+ and 460 nm InGaN chip, showing a warm white light emission with low correlated color temperature (4474K) and high color rendering index (90.8). The result implies that the Li3Cs0.5Rb0.5Ge8O18:1%Mn4+ phosphor can be used as a potential red phosphor for pc-WLED application.

Moisture resistance, luminescence enhancement, energy transfer and tunable color of novel core-shell structure BaGeF6:Mn4+ phosphor

Recently, Mn4+-doped narrow band red-emitting fluoride phosphors with exceptional luminescence properties have been widely studied for improving the performance of white light-emitting diodes (WLEDs). However, the poor water stability and single luminescent color limit their wider application. Herein, the design idea of new core-shell structure is proposed to improve the properties of BaGeF6:Mn4+ red phosphors by coating poly propylene glycol (PPG) and NaGdF4:Dy3+ nanoparticles. The phase purity, morphology and elemental composition are confirmed via X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), respectively. The luminescence properties of all phosphors are researched in detail with excitation spectra, emission spectra and fluorescence lifetime curves. PPG coating layer can not only modify the surface defects of the BaGeF6:Mn4+ phosphor to enhance the luminous intensity, but also successfully improve the water resistance of the phosphor. Therefore, BaGeF6:Mn4+@PPG phosphor as red component is more effective for packaging warm WLED. In addition, PPG is considered as the adsorption media layer to connect BaGeF6:Mn4+ phosphors and NaGdF4:Dy3+ nanoparticles. The as-synthesized BaGeF6:Mn4+@PPG-NaGdF4:Dy3+ composite phosphors can emit blue, yellow and red light simultaneously under the excitation of ultraviolet light. The energy transfer processes from Gd3+ to Dy3+ and from Dy3+ to Mn4+ are systematically discussed. By changing the doping concentration of Mn4+ and excitation wavelengths, the photochromic properties of the composite phosphor are successfully realized and the warm white light emission is obtained under the excitation of ultraviolet light. These findings demonstrate that the BaGeF6:Mn4+@PPG-NaGdF4:Dy3+ composite phosphors have more value for practical application.

Dual‐Guest Functionalized Zeolitic Imidazolate Framework‐8 for 3D Printing White Light‐Emitting Composites

AbstractMetal–organic frameworks (MOFs) stand as a promising chemically active host scaffold for the encapsulation of functional guests, because they could enhance luminescent properties by molecular separation of fluorophores in the nanoscale pores of the MOF crystals. Herein, simultaneous nanoconfinement of two fluorophores is shown, namely, A) fluorescein and B) rhodamine B in the sodalite cages of ZIF‐8, constructed under ambient conditions through a simple one‐pot reaction. A novel Dual‐Guest@MOF system is reported, termed: A+B@ZIF‐8, which overcomes the intrinsic problem of aggregation‐caused quenching in the solid state to gain bright yellow emission under UV irradiation. Subsequently, this yellow emitter is combined with a blue‐emitting photopolymer resin, to yield a 3D printable luminescent composite material. A number of 3D printable composite objects for converting UV into warm white light emission are designed, achieving a high quantum yield of ≈44% in the solid state 3D printed form. This research instigates the bespoke application of a vast range of 3D printable Guest@MOF designer composites targeting energy‐saving lighting devices, smart sensors, and future optoelectronics.

Highly chemically and thermally stable lanthanide coordination polymers for luminescent probes and white light emitting diodes

A series of isomorphic of highly chemically and thermally stable lanthanide coordination polymers exhibit luminescent probe and warm white-light emission.

All-inorganic silicon white light-emitting device with an external quantum efficiency of 1.0.

With low toxicity and high abundance of silicon, silicon nanocrystal (Si-NC) based white light-emitting device (WLED) is expected to be an alternative promising choice for general lighting in a cost-effective and environmentally friendly manner. Therefore, an all-inorganic Si-NC based WLED was reported for the first time in this paper. The active layer was made by mixing freestanding Si-NCs with hydrogen silsesquioxane (HSQ), followed by annealing and preparing the carrier transport layer and electrodes to complete the fabrication of an LED. Under forward biased condition, the electroluminescence (EL) spectrum of the LED showed a broadband spectrum. It was attributed to the mechanism of differential passivation of Si-NCs. The performance of LED could be optimized by modifying the annealing temperature and ratio of Si-NCs to HSQ in the active layer. The external quantum efficiency (EQE) peak of the Si WLED was 1.0% with a corresponding luminance of 225.8 cd/m2, and the onset voltage of the WLED was 2.9V. The chromaticity of the WLED indicated a warm white light emission.

Warm-white light emission in Er3+/Tm3+/Yb3+ tri-doped YNbO4 phosphor under 808 nm excitation: A synergistic upconversion effect

Red, green and blue upconversion emissions has been reported under the 808 nm excitation in Ln3+ (Ln3+ = Er3+, Tm3+, Yb3+) doped YNbO4 (YNO) phosphors prepared by the solid-state reaction method. Warm-white upconversion emission with CIE color coordinates equal to x = 0.34 and y = 0.35 was obtained in the YNO: 0.5%Er3+2.0%Tm3+15%Yb3+ composition under 9 W/cm2. This result was possible due to efficient synergistic process between Er3+/Tm3+ and Yb3+ ions. The significant improvement of red emission in the tri-doped sample was explained by the energy-transfer between Er3+ and Tm3+ ions. The upconversion mechanism and population processes are discussed in details.

Insight into the synthesis and luminescence properties of the single-ion-activated single-phased Na3ScSi2O7:Dy3+ phosphor for white light-emitting diodes

In recent years, single-ion activated single-phase white phosphors played a crucial role in the field of near-ultraviolet (n-UV) white light-emitting diode (w-LED) illumination. In this work, a series of Na3Sc1–xSi2O7:xDy3+ phosphors was successfully prepared by high-temperature solid-state reaction method. The morphology and phase composition of the phosphors were confirmed by X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). Due to the 6H15/2 → 6P7/2 transition of Dy3+, the photoluminescence (PL) excitation spectrum of Na3Sc1–xSi2O7:xDy3+ exhibits a series of absorption peaks in the range of 250–450 nm and the strongest excitation peak is located at 349 nm. The PL spectra shows that the optimal doping concentration of Dy3+ is 0.13, which is controlled by dipole–dipole interaction according to the corresponding concentration quenching mechanism. The thermal stability of Na3Sc0.87Si2O7:0.13Dy3+ phosphor was investigated in detail and the compound has good thermal stability with activation energy of 0.198 eV. The decay time value of Na3Sc0.87Si2O7:0.13Dy3+ phosphor was calculated to be 0.4015 ms. The CIE chromaticity coordinates indicated that the phosphor produced warm white-light emission and testified the potential application of Na3ScSi2O7:Dy3+ as a new-style w-LEDs phosphor.

Color-tunable visible photoluminescence of Eu:CaF2single crystals: variations of valence state and local lattice environment of Eu ions

In this article, Eu-activated CaF2 single crystals were synthesized by Bridgman-Stockbarge method. The dependence of photoluminescence properties of Eu: CaF2 crystals in UV-Vis regions on EuF3 doping concentrations were investigated. While the EuF3 doping concentration is increased from 0.6% to 6.0%, the CIE (Commission Internationale de L'Eclairage) color coordinates of Eu: CaF2 crystals can be tuned from (0.28, 0.12) to (0.60, 0.38), corresponding to the luminescence color from blue to orange. XPS (X-ray Photoelectron Spectroscopy) measurements indicated that Eu2+ and Eu3+ ions both existed in the crystals. With EuF3 doping concentration increasing, the proportion of Eu3+ ions increase from 16.73% to 39.00%, while that of Eu2+ ions decrease from 83.27% to 61.00%. Moreover, the integrated intensity ratio (R) of the 614 nm to 593 nm of Eu3+ ions increase from 0.38 to 0.44, indicating the local lattice environment symmetry of Eu3+ ions become lower with higher EuF3 doping concentrations. Furthermore, the CIE chromaticity coordinates of Eu: CaF2 crystals greatly depend on the excitation wavelength. The warm white-light emission has been realized in 0.6%Eu: CaF2 crystal when the excitation wavelength is around 322 nm.

Photoluminescence properties and energy transfer in a novel Sr8ZnY(PO4)7:Tb3+,Eu3+ phosphor with high thermal stability and its great potential for application in warm white light emitting diodes

Energy transfer from Tb3+ to Eu3+ was observed and verified in a warm white light emission phosphor SZYP:Tb3+,Eu3+ with high thermal stability.

A red-emitting Sr3La(1-x)Eu x (AlO)3(BO3)4 phosphor with high thermal stability and color purity for near-UV-excited wLEDs.

A high efficiency red-emitting Eu3+ doped Sr3La(AlO)3(BO3)4 phosphor has been calcined successfully through a traditional solid-state method, and the photoluminescence and cathode-luminescence properties of samples are investigated in detail. The result of density functional theory (DFT) calculation shows that the Sr3La(AlO)3(BO3)4 host lattice has an indirect band gap. The broad excitation ranges from 200 nm to 500 nm, especially the strongest excitation located in the near ultraviolet (near-UV) region, suggests that the phosphor can match well with not only blue LED chips but also near-UV LED chips. Besides, the phosphor can emit bright red light peaking at 596, 618, 655 and 706 nm under either near-UV or blue light excitation and the internal quantum efficiency can reach 40%. The temperature-dependent PL properties and calculation of color purity show that the phosphor has an excellent thermal stability and outstanding color stability. Ultimately, by employing Sr3La(AlO)3(BO3)4:Eu3+ phosphor as a red light component, a stable warm white light emission is obtained with Ra = 80, CIE = (0.3443, 0.2903) and CCT = 4680 K. These results indicate that red Sr3La(AlO)3(BO3)4:Eu3+ phosphor may have a great potential for wLEDs with fantastic properties.

Near UV excitable warm white light emitting Zn doped γ-Ga2O3 nanoparticles for phosphor-converted white light emitting diode

Optical properties of Zn doped γ-Ga2O3 nanoparticles are investigated for the generation of white light, using near UV LED chip for phosphor-converted WLED (pc-WLED) application. Sol-gel combustion technique is adopted for the synthesis of Zn doped γ-Ga2O3 nanoparticles. The synthesized Ga2O3 nanoparticles are formed as metastable γ-phase with the face-centred cubic crystal structure. The structural stability is maintained up to 15 mol% doping of Zn ions. Formation of aggregated ultrafine particles of undoped and Zn doped γ-Ga2O3 with size less than 4 nm is found from TEM results. Doping of Zn ions has altered the optical band gap of γ-Ga2O3, and it varies from 4.13 to 3.97 eV. Broad visible emission in the wavelength range of 400–600 nm is observed and broadening of emission band increases after Zn doping. Formation of high defect concentration and smaller size of 10 mol% Zn doped γ-Ga2O3 nanoparticles resulted in higher emission intensity. Wide photoluminescence excitation band from 330 to 475 nm suggests that wide visible emission can be obtained from Zn doped γ-Ga2O3 nanoparticles with the excitation of both near UV and blue light. The bi-exponential behavior of PL decay curves of emission bands at the blue and yellow region indicated the complicate luminescence process of Zn doped γ-Ga2O3. The estimated lifetime of blue emission varies from 30 to 37 ns and of yellow emission varies from 54 to 62 ns. Under the excitation of 375 nm LED chip, warm white light emission with CIE color coordinates of (0.42, 0.33), color rendering index of ~ 87 and CCT of 2365 K is obtained for 10 mol% Zn doped γ-Ga2O3 nanoparticles which exemplifying its potential application in pc-WLED fabrication.

Tunable luminescence and energy transfer of Dy3+-activated Bi4Si3O12--Bi4Ge3O12 pseudo-system phosphor for warm white-emitting

Dy3+-activated Bi4Si3O12-Bi4Ge3O12 pseudo-system phosphors have been synthesized by a solid state reaction method and characterized using XRD, SEM and fluorescence spectrometry. Upon 279 nm excitation, the emission of Dy3+ ions is observed at 486 nm (blue), 574 nm (yellow) and 662 nm (red), corresponding to 4F9/2 → 6H15/2, 4F9/2 → 6H13/2 and 4F9/2 → 6H11/2 transitions, respectively. The different kinds of excitation for the luminescence intensity behaviors have been discussed through efficient Bi3+ → Dy3+ energy transfer. As Si4+ is substituted by Ge4+, the crystallization and the intensity of emission are improved; however, the value of correlated color temperature (CCT) is also increased. The values of CIE chromaticity coordinates and CCT endorse warm white light emission from the phosphor. The paper shows that phosphor could be a potential single-emitting-component warm white emitting for LED applications.

Wide range yellow emission Sr8MgLa(PO4)7: Eu2+, Mn2+, Tb3+ phosphors for near ultraviolet white LEDs

A series of single phased phosphors Sr8MgLa(PO4)7: Eu2+, Mn2+, Tb3+ were synthesized by solid state reaction methods for applications of white light emitting diodes(w-LEDs). The broad absorption band at the near ultraviolet (NUV) region of 250–450 nm was obtained, which is ascribed to the 4f7→ 4f65d1 electronic transition of the Eu2+ ions. Under NUV excitation, the broad yellow emission was obtained from tri-activated Sr8MgLa(PO4)7 phosphors via combining three emission bands centered at 500, 550, and 600 nm contributed by Eu2+, Tb3+ and Mn2+, respectively. The optimized concentrations of Mn2+ and Tb3+ were 6 mol%, respectively, which enhanced the total PL intensity up to 30% comparing to only Eu2+ doped phosphor. Moreover, the quantum efficiency of Sr8MgLa(PO4)7: Eu2+, Mn2+, Tb3+ phosphor had achieved up to 52%. The combination of a NUV chip with compound of Sr8MgLa(PO4)7: Eu2+, Mn2+, Tb3+ and BaMgAl10O17:Eu2+ achieved tunable w-LEDs with high CRI. The results suggest that this single phased Sr8MgLa(PO4)7: Eu2+, Mn2+, Tb3+ phosphor can be a key for the phosphor converted w-LEDs for warm white light emission.