Warm White Light-emitting Diodes Research Articles

Efficient blue-light-excited cyan-emitting CaLu2HfScAl3O12:Ce3+ phosphors for full-visible-spectrum warm-white LEDs

Bright cyan-emitting phosphor is indispensable to fill the cyan gap for the fabrication of full-visible-spectrum warm-white light-emitting diodes (LEDs) with high color rendering index (CRI). In this study, we demonstrate a novel efficient cyan-emitting Ce3+-activated CaLu2HfScAl3O12 (CLHSA) garnet phosphor for application in blue-light-excited full-spectrum warm-white LEDs. CLHSA:Ce3+ phosphors show broadband excitation spectra in the 300–470 nm spectral range with a maximum peak at 408 nm, indicating they can be efficiently pumped by the blue LED chips. The optimal doping concentration of Ce3+ ions is found to be 1 mol%. Upon 408 nm excitation, the optimal CLHSA:1%Ce3+ phosphor gives rise to a bright broadband cyan emission (peak position: 498 nm; bandwidth: 97.5 nm) with CIE chromaticity coordinates of (0.2196, 0.4265) and high photoluminescence quantum yield of 64.5%. Finally, we have fabricated a blue-light-excited high-CRI warm-white LED device by employing the CLHSA:1%Ce3+ cyan phosphor, commercial YAG:Ce3+ yellow phosphor and commercial CaAlSiN3:Eu2+ red phosphor as well as a 450 nm LED chip, which demonstrates a bright warm-white light emission with a high CRI (Ra = 92.6), a low correlated color temperature (3660 K), and good CIE chromaticity coordinates of (0.3993, 0.3939) as well as a high luminous efficacy of 45 lmW−1. Therefore, this newly discovered efficient cyan-emitting CLHSA:1%Ce3+ phosphor is promising for application in blue-chip-pumped full-visible-spectrum warm-white LEDs with high CRI values.

A yellow-green-emitting graphitic-C3N4 derivative consisting of 1,4-phenylene-inserted heptazine units: Preparation and application as a metal-free phosphor for white LEDs

To develop non-rare-earth or metal-free phosphors for white light-emitting diodes (WLEDs) are very significant and forward-looking. Here, a yellow-green-emitting g-C3N4 derivative (p-Ph-g-C3N4) consisting of 1,4-phenylene-inserted heptazine units was successfully prepared by 6,6'-(1,4-phenylene)bis(1,3,5-triazine-2,4-diamine) via thermal polymerization. Its emission is mainly located at 450–700 nm with the maximum wavelength (λem,max) of 536 nm, its quantum yield (QY) is 15.7% (λex = 430 nm) which is much higher than that of bulk g-C3N4 (ca. 5%). Under the excitation of 430 nm blue-emitting GaN-based chips (ca. 4.0 lm·W−1), p-Ph-g-C3N4 together with non-rare-earth red-emitting K2SiF6:Mn4+ as phosphors, a series of cold, neutral, and warm WLEDs with good performances were fabricated. As for the best one, its color rendering index (CRI) is 84.3, correlate color temperature (CCT) is 5702 K, luminous efficiency (LE) is 5.40 lm·W−1, moreover, its CIE value (0.30, 0.34) is very close to (0.33, 0.33) of pure white light. The research results indicate p-Ph-g-C3N4 can be used as an efficient metal-free quasi-green phosphor for WLEDs.

Optimizing the luminescent performance and water resistance of K2SiF6:Mn4+ phosphor by doping Li+ and coating BaSO4

Mn4+ activated K2SiF6 red phosphors have attracted widespread attention, while the poor moisture resistance restrains their further applications. In order to optimize the luminescence intensity of the K2SiF6:Mn4+ red phosphors immersed in water, we synthesized K2SiF6:Mn4+, Li + red phosphors with LiF as lithium source. The luminous intensity of K2SiF6:Mn4+, Li+ phosphor is approximately 133% of K2SiF6:Mn4+ red phosphors. By coating BaSO4 layer on the surface of K2SiF6:Mn4+, Li+ samples, the luminous intensity of K2SiF6:Mn4+, Li+@BaSO4 red phosphor maintains 83% of the initial intensity after soaking in water for 6 h. In addition, the K2SiF6:Mn4+, Li+@0.8 BaSO4 red phosphor has higher luminous intensity at 150 °C. Finally, by combining with InGaN blue chip and yellow phosphor (YAG:Ce3+) to fabricate warm white LED devices, the warm white LED device based on K2SiF6:Mn4+, Li+@0.8 BaSO4 red phosphor has excellent performance (CCT = 3558 K, CRI = 91.4).

Realizing full-spectrum LED lighting with a bright broadband cyan-green-emitting CaY2ZrGaAl3O12:Ce3+ garnet phosphor

Full-visible-spectrum white light-emitting diodes (LEDs) with ultrahigh color rendering index (CRI), which are capable of offering a light source that mimics natural sunlight, have great application potentials in healthy lighting, high-resolution displays, and plant growth lighting. However, cyan gap in the 480–520 nm wavelength range is commonly existed in the emission spectra of traditional phosphor-converted white LEDs, and thus it is urgent to develop high-performance cyan-emitting phosphors to close this spectral gap for realizing full-visible-spectrum LED lighting. Herein, we demonstrate a new efficient cyan-green-emitting Ce3+-activated CaY2ZrGaAl3O12 garnet phosphor for near-ultraviolet (near-UV) pumped full-visible-spectrum warm-white LEDs. The CaY2ZrGaAl3O12:Ce3+ cyan-green phosphor has a cubic structure with the space group Ia3‾d and lattice parameters of a = b = c = 12.39645(8) Å and V = 1886.08(6) Å3. Ce3+ doping concentration dependent luminescence properties have been studied, and the highest emission intensity is obtained at 1 mol%. The optimal CaY2ZrGaAl3O12:1%Ce3+ sample shows a broad excitation band in the 300–490 nm wavelength range with peak at 409 nm due to the 4f→5d transition of Ce3+ ions. Upon 409 nm excitation, CaY2ZrGaAl3O12:1%Ce3+ produces a wide cyan-green emission band in the 425–750 nm spectral range with a peak at 514 nm and a full width at half-maximum of 110 nm owing to the 5d→4f transition of Ce3+ ions, and the corresponding CIE color coordinates and internal quantum efficiency are determined to be (0.2802, 0.4856) and 56%, respectively. Furthermore, the resulting CaY2ZrGaAl3O12:1%Ce3+ phosphor exhibits good thermal stability, and its emission intensity at 423 K is about 58% of that at 303 K. Finally, a white LED device is fabricated by employing a 395 nm near-UV chip with the phosphor blend of commercial BaMgAl10O17:Eu2+ blue phosphor, as-prepared CaY2ZrGaAl3O12:1%Ce3+ cyan-green phosphor, commercial (Ba,Sr)2SiO4:Eu2+ green phosphor and commercial CaAlSiN3:Eu2+ red phosphor, which exhibits a bright full-spectrum warm-white light with low color correlated temperature of 3334 K and ultrahigh CRI values (Ra = 97, R9 = 95.3, R12 = 90.1) for 20 mA driving current. This work provides a new perspective in designing luminescent materials for high-color-quality full-visible-spectrum LED lighting.

Efficient tunable photoluminescence of Dy3+/Eu3+ co-doped OFSZBS glasses for warm white LEDs

A series of oxyfluoride strontium zinc borosilicate (OFSZBS) glasses co-doped with Dy3+/Eu3+ ions was prepared via melt quench method. The structural properties were examined using XRD and scanning electron microscope (SEM) with energy dispersive X-ray analysis (EDX) on DE2.0 and undoped OFSZBS glasses, respectively. UV–Vis absorption spectroscopy was used to evaluate the direct & indirect energy band gaps. At different excitations (348, 362, 385 and 393 nm), the photoluminescence (PL) spectra were observed with tuned light. Warm white light was generated through the Dy3+ (4F9/2→6H15/2, 6H13/2) and Eu3+ (5D0→7F2) transitions. Dexter Reisfield approximation applied to PL data revealed a dipole-dipole (d-d) mechanism accountable for the energy transfer (non-radiative) between sensitizer (Dy3+) and activator (Eu3+) ions. The energy transfer efficiency in the co-doped glass samples was found between 8% to 50%, depending on the doping. The Inokuti-Hirayama (I-H) fitting of PL decay profiles also confirm the energy transfer mechanism. The CIE chromaticity color coordinates observed for OFSZBSDE2.0 glass also confirm the color tunability. The above findings reveal the applications of as-prepared Dy3+/Eu3+ co-doped OFSZBS glasses excited using n-UV light for warm white LEDs and tuned devices.

Towards efficient blue Eu2+ activated pyrophosphate phosphor for warm white LED applications

A blue-emitting LiCsBaP2O7:Eu2+(LCBPO:Eu2+) pyrophosphate phosphor prepared by solid-state synthesis that emits bright blue light with a first-rate internal quantum efficiency and high color purity is reported. Furthermore, when heated from 298 K to 473 K, LCBPO:0.015Eu2+ phosphor exhibits excellent color stability. Impressively, LCBPO:0.015Eu2+ blue phosphor exhibits exceptional stability against air exposure over a month. Fabricating a near-ultraviolet (n-UV) pumped pc-wLED using LCBPO:0.015Eu2+ along with green (Sr,Ba)2SiO4:Eu2+ and red (Ca,Sr)AlSiN3:Eu2+ phosphors demonstrates a well distributed warm white light with a high color-rendering index (Ra) of 91.7, a low correlated color temperature (CCT) of 3382 K and a high luminous efficiency (LE) of 26.1 l m/W. The high-performance optical characteristics, straightforward synthesis procedures and economical initial materials cost of LCBPO:Eu2+ support the potential of this material for usage in warm white LED-based lighting systems.

Realizing thermal and moisture stability in the K2Ge1-xTixF6:Mn4+ red phosphors with high efficiency for WLEDs

Developing red light-emitting phosphors with high performances is an imperative issue for achieving high-quality warm white light-emitting diodes. Here, red light-emitting K2Ge1-xTixF6:Mn4+ phosphors with high luminescence performances are obtained. Benefiting from the Ti4+-doping in K2GeF6, a high internal quantum yield of 96% can be obtained. The emission intensity at 423 K keeps 83% of the initial value at 298 K in K2Ge0.6Ti0·4F6:Mn4+. The moisture resistance property of K2Ge0.6Ti0·4F6:Mn4+ is significantly enhanced and can keep 71% of the original luminescence intensity after immersing in deionized water for 180 min. A warm white light-emitting diode with high color rendering index of 92.4, low correlated color temperatures of 3113 K, and high luminous efficiency of 123.1 l m/W is simultaneously obtained by encapsulating K2Ge0.6Ti0·4F6:Mn4+ with commercial yellow phosphor on blue chips. This work proves the prospects of K2Ge1-xTixF6:Mn4+ as promising red phosphors for potentially viable application in warm white light-emitting diodes.

Optical analysis of Dy3+/Sm3+ co-doped NaY(MoO4)2 phosphors for warm white LED

A series of NaY(MoO4)2: RE3+(RE=Dy3+, Sm3+) materials were synthesized by high temperature solid phase method and coated on UV chip to prepare white light LED devices. XRD and SEM scans showed that the material was small spherical particles, and the crystal form was consistent with the standard NaY(MoO4)2. The fluorescence spectrum analysis shows that under the excitation of 400 nm near-ultraviolet light, NaY(MoO4)2: Dy3+, Sm3+ materials show 482 nm blue light and 570 nm green-yellow light corresponding to the characteristic transitions of 4F9/2→6H15/2 and 4F9/2→6H13/2 of Dy3+, while yellow light at 600 nm and red light at 646 nm, on the other hand, correspond to characteristic transitions of 4G5/2→6H7/2 and 4G5/2→6H9/2 for Sm3+. Under the excitation of near ultraviolet light, the superposition of three colors can form a good white light emission. According to Dexter 's theory of energy transfer method, it is calculated that the mechanism of energy transfer is galvanic dipole-galvanic dipole interaction. The white light LED device can realize warm white light emission (3705 K) alone, and greatly reduce the cost under the premise of reducing the harm of blue light to the human eye. It suggests that this material is an excellent single substrate white phosphor material that can be applied to near-UV excited white LEDs.

Up and down-conversion photoluminescence energy demonstration of Ho3+/Yb3+ co-doped double perovskites microcrystals

Recently, lanthanide-doped fluorescence materials with perovskite structures have attracted great attention due to their abundant 4f energy levels, of which up- and down-conversion photoluminescence (PL) usually can be achieved by energy-level transition of single or multiple rare-earth ions (REI). Here, we synthesized for the first time a series of holmium (Ho) and ytterbium (Yb) co-doped Cs2Ag0.4Na0.6In0.9Bi0.1Cl6 (CANIBC) microcrystals (MCs) by hydrothermal method and realized the synergistic effect of efficient dual-mode PL of host and REI. The CANIBC MCs show yellow-white light emission stimulated by a 405 nm laser, of which the down-conversion (DC) PL is superimposed by the self-trapped excitons (STEs) emission of [AgCl6]5- octahedral and the energy level leap emission of REI. While the green emission of Ho3+ can be observed on the up-conversion (UC) PL stimulated by a 980 nm laser. We systematically analyzed the effect of CANIBC MCs in the dual-mode PL by time-resolved spectroscopy and found the existence of energy transfer between the STEs to REI in the DC PL process. Whereas in UC PL there is only energy transfer between REI. The variable-temperature dual-mode PL, reflects good temperature measurement performance. Simultaneously, it is effectively processed into a powder and mixed with 415 nm chips to create warm white light-emitting diodes with a CIE of (0.34, 0.36).

A 3-Fluoropyridine Manipulating the Aggregation and Fibril Network of Donor Polymers for Eco-Friendly Solution-Processed Versatile Organic Solar Cells.

The development of eco-friendly solvent-processed organic solar cells (OSCs) suitable for industrial-scale production should be now considered the imperative research. Herein, asymmetric 3-fluoropyridine (FPy) unit is used to control the aggregation and fibril network of polymer blends. Notably, terpolymer PM6(FPy = 0.2) incorporating 20% FPy in a well-known donor polymer poly[(2,6-(4,8-bis(5-(2-ethylhexyl-3-fluoro)thiophen-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione)] (PM6) can reduce the regioregularity of the polymer backbone and endow them with much-enhanced solubility in eco-friendly solvents. Accordingly, the excellent adaptability for fabricating versatile devices based on PM6(FPy = 0.2) by toluene processing is demonstrated. The resulting OSCs exhibit a high power conversion efficiency (PCE) of 16.1% (17.0% by processed with chloroform) and low batch-to-batch variation. Moreover, by controlling the donor-to-acceptor weight ratio at 0.5:1.0 and 0.25:1.0, semi-transparent OSCs (ST-OSCs) yield significant light utilization efficiencies of 3.61% and 3.67%, respectively. For large-area (1.0cm2 ) indoor OSC (I-OSC), a high PCE of 20.6% is achieved with an appropriate energy loss of 0.61eV under a warm white light-emitting diode (3,000K) with the illumination of 958lux. Finally, the long-term stability of the devices is evaluated by investigating their structure-performance-stability relationship. This work provides an effective approach to realizing eco-friendly, efficient, and stable OSCs/ST-OSCs/I-OSCs.

Structure and photoluminescence studies of Rb3GdSi2O7: Eu2+ phosphor used for NUV converted white LEDs

In pursuit of healthy lighting, the exploitation of high-quality Eu2+-activated phosphors available for near-ultraviolet light-emitting diode (NUV-LED) chip-based white LED (WLED) has fetched growing interest. Herein, a novel NUV-light excitable Rb3GdSi2O7: Eu2+ phosphor is successfully synthesized via a high-temperature solid-state reaction method. The crystal structure of Rb3GdSi2O7 is found to be hexagonal, belonging to space group P63/mmc. The Rb3GdSi2O7: Eu2+ phosphor exhibits a broad excitation band in the 300–450 nm wavelength range, and it emits strong yellow-green light with peak at 543 nm upon 365 nm excitation. Benefitting from the high structure rigidity of host matrix, Rb3GdSi2O7: Eu2+ also possesses a desired luminescence thermal stability (423 K, 85.6%). The WLED device fabricated using a 365 nm chip and a blend of the as-prepared Rb3GdSi2O7: Eu2+ yellow-green phosphor and commercial BaMgAl10O17: Eu2+ blue phosphor displays an excellent color-rendering index of 95.9 at a low correlated color temperature of 4373 K. This work confirms the applicative potential of Rb3GdSi2O7: Eu2+ in NUV-converted warm WLEDs, which may promote the development of high-color-quality healthy lighting.

Spectral Light Treatment Influenced Morpho-Physiological Properties and Carvacrol Accumulation in Indian Borage.

The online version contains supplementary material available at 10.1007/s00344-023-11028-6.

Highly thermostable mixed lanthanide organic frameworks with high quantum yield for warm white light-emitting diodes.

A mixed lanthanide organic framework was prepared via hydrothermal methods using m-phthalic acid (m-H2BDC), 1,10-phenanthroline (1,10-Phen), and Ln3+ ions, formulated as [HNMe2][Eu0.095Tb1.905(m-BDC)3(phen)2] (ZTU-6). The structure and stability of ZTU-6 were characterised by X-ray diffraction (XRD) and thermogravimetric analysis (TGA), which revealed a three-dimensional pcu topology with high thermal stability. Fluorescence tests showed that ZTU-6 emitted orange light with a high quantum yield of 79.15%, and it can be effectively encapsulated in a light-emitting diode (LED) device emitting orange light. In addition, ZTU-6 was found to be compatible with BaMgAl10O17:Eu2+ (BAM) blue powder and [(Sr,Ba)2SiO4:Eu2+] silicate yellow and green powder to create a warm white LED with a high colour rendering index (CRI) of 93.4, a correlated colour temperature (CCT) of 3908K, and CIE coordinates of (0.38, 036).

Recycling the Energy of Indoor Light: Highly Efficient Organic Photovoltaics via a Ternary Strategy

A ternary approach in organic photovoltaics (OPVs) is simple and reliable to effectively tune the optical, electrical, and morphological properties of the photoactive layer for high efficiency as well as long-term stability under 1 sun. However, there have been few papers reporting the benefits of ternary systems for recycling the energy of indoor light, which has narrow emission spectra and weak illumination compared to outdoor light. In this study, by using two compatible donor polymers (PM7 and PM7 D1) with slightly different band gaps and similar chemical structures, we demonstrate a simultaneous modulation of light absorption and molecular packing under ambient conditions, which resulted in efficient indoor OPVs exhibiting power conversion efficiency (PCE) over 20% under 1000 lx of warm white light-emitting diode (2900 K). From morphological analysis, we infer that PM7 serves to seed the nucleation of PM7 D1 in the ternary blend, templating its crystallization and alignment along the PM7 backbone. Such templating effect leads to increased domain spacing and relative degree of crystallinity (rDoC) compared to those of each binary system. We further show that higher rDoC helps suppress both bimolecular and trap-assisted recombination of photogenerated charges in the ternary devices. As a result, the complementary absorption and synergistic molecular assembly of the two donor polymers enhance the short-circuit current density as to increase the average PCEs from 9.6 to 10.3% under 1 sun and from 18.7 to 20.0% under 1000 lx. We envision that our strategy of incorporating both a planar and a flexible donor polymer with similar chemical structures can be generally applicable to attain a high-performance ternary OPV under both 1 sun and indoor light.

Designing multicolor luminescence in Tb3+/Eu3+-codoped KGd2F7 nanoparticles through energy transfer engineering for warm white light-emitting diode

By a facile precipitation method at room temperature, series of Tb3+-doped and Tb3+/Eu3+-codoped KGd2F7 nanoparticles (NPs) were synthesized. Upon 377 nm excitation, Tb3+-doped KGd2F7 NPs possess intense green emissions and their strongest intensities are obtained when Tb3+ ion is 30 mol%, where the corresponding concentration quenching mechanism is electric dipole-quadrupole interaction. As for Tb3+/Eu3+-codoped KGd2F7 NPs, dazzling multi-color emissions are achieved, excited by 377 nm, triggered by the energy transfer (ET) from Tb3+ to Eu3+. Specially, the emitting color is changed from green to yellow and finally to red as Eu3+ content increases. Through systematical discussion based on the emission spectra and decay time, the ET mechanism is decided by dipole-dipole interaction. Moreover, Tb3+/Eu3+-codoped KGd2F7 NPs do not only have high thermal stability but also exhibit admirable quantum efficiency of 65.7% excited by 377 nm. Furthermore, through utilizing the resultant NPs as yellow-emitting components, a warm white light-emitting diode with high color rendering index (85.5) and low correlated color temperature (4323 K) is fabricated, which are insensitive to injection current. Our findings may provide promising luminescence materials with multicolor emissions to meet the requirement of phosphor-converted solid-state lighting.

Highly luminescent and thermostable R6G@DUT-52 composite for sensing Fe3+ ion and white light emitting diode

Introduction of the yellow rhodamine 6G (R6G) fluorescent dyes into the nanopores of DUT-52 has been successfully achieved the R6G@DUT-52 composite by the one-pot hydrothermal method. Its structure, stability and morphology are well characterized by the XRD, TGA and SEM, whose fluorescent properties are also studied in detail. The obtained R6G@DUT-52 exhibits the highly thermostability with the blue emission of the DUT-52 at 435 nm, the characteristic emission of R6G dyes at 568 nm and the highly quantum yields (QY) of 77.8%, which shows the potential application prospects as the probes for high selectivity and sensitivity of detecting Fe3+ ion from 12 kinds of metals ions. In addition, R6G@DUT-52 is cooperated with the commercial green phosphor powder (GGA) that is further encapsulated on the 455 nm blue LED chip to achieve the warm white light emitting diode (WLED) device with the CIE coordinates of (0.373, 0.364), correlated color temperature (CCT) of 4107 K and luminous efficiency (LE) of 113.08 lm/w.

Green synthesis strategy to construct strong zero-phonon line red emission phosphor Na2SiF6:Mn4+: Photoluminescence properties, thermal stability and application in warm white LEDs

Green synthesis strategy to construct strong zero-phonon line red emission phosphor Na2SiF6:Mn4+: Photoluminescence properties, thermal stability and application in warm white LEDs

Highly efficient and water-resistant K3ZrF7:Mn4+ red-emitting phosphors

Mn4+ activated fluorides are promising red phosphors to be used in warm white light emitting diodes and liquid crystal display (LCD) backlighting due to their unique narrow-band red emission and broad band absorption in blue wavelength region. However, the instability in humid environment of these phosphors limited their practical application. In this work, we developed a facile co-precipitate method to prepare Mn4+ doped K3ZrF7 phosphors with good water-resistant properties. The crystal structure of K3ZrF7 was analyzed by XRD Rietveld refinement. The photoluminescence intensity was maintained at 95% after being immersed in water for 40 min in comparison with only 39.8% for Mn4+ doped K2TiF6 phosphors. The intrinsic seven coordination environment of Mn4+ in K3ZrF7 crystal was proposed as the main reason contributing to the good water resistance of the sample. The internal quantum efficiency and external quantum efficiency of optimized K3ZrF7:Mn4+ was measured to be 70.8% and 19.5% respectively. The thermal stability of the obtained phosphors was studied. A warm white light LED device with color temperature of 4074 K and color rendering index of 76.5 was fabricated by combining a mixture of K3ZrF7:Mn4+ and Y3Al5O12:Ce3+ with a blue InGaN chip.

P3HT vs Spiro-OMeTAD as a hole transport layer for halide perovskite indoor photovoltaics and self-powering of motion sensors

Recent years have witnessed the emergence of indoor photovoltaic (PV) devices with the rapid development of the Internet of things technology field. Among the candidates for indoor PVs, halide perovskites are attracting enormous attention due to their outstanding optoelectronic properties suitable for indoor light harvesting. Here we investigated the indoor PV properties of CH3NH3PbI3-based devices using Spiro-OMeTAD and P3HT as the hole transport layers. The Spiro-OMeTAD-based devices show a consistently higher power conversion efficiency under indoor illumination and 1 sun, with the champion devices showing a power conversion efficiency of 21.0% and 30.1% for the forward and reverse scan under 1000 lux warm white LED illumination. Fewer trap states and higher carrier lifetime were revealed for Spiro-OMeTAD based devices compared to P3HT. The best-performed Spiro-OMeTAD-based devices are used to self-power a wearable motion sensor, which could detect human motion in real-time, to create a primary sensor system with independent power management. By attaching the Spiro-OMeTAD indoor PV device to the strain sensor, the sensor exhibits an accurate and sensitive response with finger bending movements with good repeatability and negligible degradation of mechanical stability, which indicates the success of sensor powering with the indoor PV device.

Strategic Tuning of Photophysical Response in the Polyhedral Framework of the Garnet Structure toward White Light-Emitting Devices with Enhanced Color Rendering.

Designing a single-phase phosphor with high quantum efficiency and full spectrum emission is inevitable for today's scientific world. Herein, an optimal strategy for realizing white emission in a single component matrix is envisaged based on the structure-property-design-device policy. Cationic substitution corresponding to polyhedral expansion and contraction in A2A'B2V3O12 confirms the existence of strong and intricate linkage in the garnet structure. The dodecahedral expansion causes compression of VO4 tetrahedra and a blue shift. The direct correlation of V-O bond distance with red shift validates the distortion of the VO4 tetrahedra. The interdependence of photophysical properties via cationic substitution and subsequent correlation of the V-O bond distance with emission bands enabled the tailoring of phosphor-CaSrNaMg2V3O12 with a high quantum efficiency of 52% and excellent thermal stability of 0.39 eV. Bright warm white light-emitting diode (WLED) devices are fabricated based on Eu3+ and Sm3+-activators. A high quantum efficiency-74% is obtained for the designed Eu3+ phosphor. CIE coordinates near the achromatic point (0.329, 0.366), low CCT-5623 K, and high color rendering index (CRI)-87 are obtained for the single-phase WLED device. This work puts forth a new direction for designing and engineering promising WLEDs with enhanced color rendering based on single-phase phosphors with full spectrum emission.