High Internal Quantum Efficiency Research Articles

Tailoring of Spectral Behaviors in Ce3+-Activated Ba2Gd8(SiO4)6O2 Cyan-Emitting Phosphors via Site Substitution Engineering for Plant Growth and Full-Spectrum White Light-Emitting Diodes.

Highly efficient Ce3+-activated Ba2Gd8(SiO4)6O2 (BGSO) cyan-emitting phosphors were designed to simultaneously fulfill the applications of plant growth and a white-light-emitting diode (white-LED). Here, the spectral behaviors of the studied samples are manipulated by arranging Ce3+ to occupy various crystallographic sites (i.e., Ba2+ and Gd3+) in BGSO host lattices. Upon ultraviolet light excitation, all the samples emit an intense asymmetric broadband emission from Ce3+ and its fluorescence intensity is strongly impacted by the dopant concentration and occupied position. In addition, the resultant phosphors do not only possess satisfied thermal stability but also present high internal and extra quantum efficiencies of 78.6 and 61.8%, respectively, which can be regulated by selecting the substituted sites. Two cyan-emitting LEDs are fabricated by integrating the synthesized phosphors, and their emission bands align well with the absorption peaks of plant pigments, enabling their uses in plant growth. Furthermore, the controlled plant growth environments also clarify that the packaged cyan-emitting LED can effectively promote plant growth. Additionally, via adopting the resulting phosphors as cyan-emitting converters, full-spectrum white-LED with good electroluminescence behaviors is developed. These findings manifest that the Ce3+-activated BGSO phosphors with tunable spectral properties are promising cyan-emitting components for both artificial plant growth LED and full-spectrum white-LED.

Synthesis, Characterization and Photoluminescence Studies of near-UV excitable green-emitting NaBaScSi2O7: Eu2+ phosphor with high Internal Quantum Efficiency and Remarkable Thermal Stability

Green-emitting phosphor NaBaScSi2O7:Eu2+ was synthesized by “Amorphous Metal Complex” method using water soluble silicon compound. Eu2+ doped NaBaScSi2O7 exhibited a broad green emission band centered between 500 and 510 nm. The high luminescence intensity of the as-synthesized phosphors may owe to the synthesis procedure based on Amorphous Metal Complex (AMC) method which helps in the homogeneous distribution of Eu2+ ions in the matrix as well as the double annealing in graphite and H2/N2 reducing atmosphere. Upon excitation at 365 nm, the composition-optimized NaBaScSi2O7:Eu2+ exhibited strong green light peaking at 501 nm with the CIE chromaticity (0.146, 0.375) and a high internal quantum efficiency of about 77%. The thermally stable luminescence properties were also studied. The results indicate NaBaScSi2O7:Eu2+ as an attractive candidate for use as a conversion phosphor for Phosphor Converted White light-emitting diode (pc-WLEDs) applications.

Stable Xanthene Radicals and Their Heavy Chalcogen Analogues Showing Tunable Doublet Emission from Green to Near-infrared.

Organic luminescent radicals, unlike traditional closed-shell fluorescent emitters, exhibit distinct luminescence mechanisms, offering promising potential for optoelectronic devices. To date, stable luminescent radicals have predominantly been confined to polychlorinated triphenylmethyl radicals, underscoring the need for new platforms to expand their emission spectra. In this study, we report the synthesis of stable 9-aryl-substituted xanthene radicals and their heavy chalcogen analogues (1 a-c and 2 a-c), which exhibited excellent chemical stability and emission ranging from green to near-infrared (527-714 nm). Notably, the selenium-substituted radical (1 c) demonstrates a significantly enhanced photoluminescence quantum yield of 41 % when doped into its precursor solid. Additionally, the introduction of methoxyphenyl groups has largely enhanced the stability of the radical, showcasing an excellent photostability with the longest half-life of around 1792 h. The high internal quantum efficiency of up to 81 % was further validated in organic light-emitting diode. This study introduces a novel class of stable carbon-centered radicals with high tunability and functionality for photoelectric applications.

Stable Xanthene Radicals and Their Heavy Chalcogen Analogues Showing Tunable Doublet Emission from Green to Near‐infrared

AbstractOrganic luminescent radicals, unlike traditional closed‐shell fluorescent emitters, exhibit distinct luminescence mechanisms, offering promising potential for optoelectronic devices. To date, stable luminescent radicals have predominantly been confined to polychlorinated triphenylmethyl radicals, underscoring the need for new platforms to expand their emission spectra. In this study, we report the synthesis of stable 9‐aryl‐substituted xanthene radicals and their heavy chalcogen analogues (1 a–c and 2 a–c), which exhibited excellent chemical stability and emission ranging from green to near‐infrared (527–714 nm). Notably, the selenium‐substituted radical (1 c) demonstrates a significantly enhanced photoluminescence quantum yield of 41 % when doped into its precursor solid. Additionally, the introduction of methoxyphenyl groups has largely enhanced the stability of the radical, showcasing an excellent photostability with the longest half‐life of around 1792 h. The high internal quantum efficiency of up to 81 % was further validated in organic light‐emitting diode. This study introduces a novel class of stable carbon‐centered radicals with high tunability and functionality for photoelectric applications.

Bright Transparent Glass‐Ceramic Scintillators With High Fraction (Ca, Sr, Ba)1‐xYxF2+x: Tb Nanocrystals Precipitation for X‐ray Low‐Dose Detection and High‐Resolution Imaging

AbstractTransparent glass‐ceramic (GC) scintillator offers cost‐effective and large‐scale preparation for high‐resolution X‐ray imaging and detectors. However, it remains difficult to precipitate a high fraction of lanthanide activated fluoride nanocrystals that determine scintillation properties in glass. Herein, an ionic‐covalent fluoroaluminate‐phosphate glass network structure is constructed by combining simulation and experimental study, which enables the precipitation of (Ca, Sr, Ba)1‐xYxF2+x: Tb nanocrystals with high crystallinity (30.11%). By adjusting Tb doping concentration, heat treatment temperature and duration, a high internal quantum efficiency of 76.07%, the steady‐state light yield of 12710 photons MeV−1 and the lowest X‐ray detection of 180 nGyair s−1 are obtained. Finally, a high‐resolution (23.4 lp mm−1) X‐ray imaging application is realized by using the (Ca, Sr, Ba)1‐xYxF2+x: Tb GC scintillator. This provides a new option for the development of low‐cost, high‐performance scintillators for X‐ray high‐resolution imaging and low‐dose detection applications.

Comparative investigation on carbon dots and chloride fluxes modified ZnAl2O4:Cr3+ nanophosphors for temperature sensing, cutting-edge forensic, anti-counterfeiting and w-LEDs applications

A novel Cr3+ doped ZnAl2O4 is synthesized by grafting carbon dots (CDs) and chloride fluxes (NaCl, KCl, NH4Cl) through the solid-state reaction method. Upon excitation at 530 nm wavelength, the Cr3+ ions in the ZAO NPs emit red light due to the influence of a strong crystal field. This red emission arises from the electric dipole 2Eg→4A2g of the Cr3+ ions. Among the chloride fluxes examined, NH4Cl had a significant impact on the PL intensity. Notably, when CDs are incorporated into the ZAO:7Cr3+/NH4Cl NPs, a remarkable increase of 17.25-folds in photoluminescence (PL) intensity is observed. This enhancement is substantially higher than that of CDs alone (11.23-folds) and NH4Cl alone (3.82-folds). The increased PL intensity is attributed to the Förster resonance energy transfer (FRET) mechanism. Furthermore, the addition of CDs (5 wt.%) enhanced the colour purity (CP) of ZAO:7Cr3+/NH4Cl NCs to 99.8%, achieving a high Internal quantum efficiency (IQE) of 93.4 %. Notably, the CDs (5 wt.%)@ZAO:7Cr3+/NH4Cl NCs maintained 92.43 % of their emission intensity even at 420 K, demonstrating exceptional thermal stability compared to ZAO:7Cr3+ NPs. Moreover, the NPs holds promise for optical thermometry, boasting a high relative sensitivity (Sr) of 6.74 × 10–2 %K-1 across a temperature range spanning from 300 to 480 K. Moreover, the latent fingerprints (LFPs) developed using CDs(5 wt.%)@ZAO:7Cr3+/NH4Cl NCs demonstrate remarkable selectivity and high contrast. Under UV irradiation, the structural features of LFPs at levels I–III are clearly visible. In addition, the strong red fluorescence emitted by CDs(5 wt.%)@ZAO:7Cr3+/NH4Cl NCs makes them suitable for applications in AC. CDs(5 wt.%)@ZAO:7Cr3+ NCs exhibit significant potential for w-LED fabrication, achieving a correlated colour temperature (CCT) of 5517 K, a CIE coordinate of (0.332, 0.331), and a high colour rendering index (CRI) of Ra = 94, outperforming ZAO:7Cr3+/NH4Cl NPs. Overall results clearly demonstrates that, CDs(5 wt.%)@ZAO:7Cr3+/NH4Cl NCs are effective for applications in optical thermometry, dactyloscopy, w-LEDs, and AC.

Growth and Characterization of High Internal Quantum Efficiency Semipolar (101̅3) GaN-Based Light Emitting Diodes

Growth and Characterization of High Internal Quantum Efficiency Semipolar (101̅3) GaN-Based Light Emitting Diodes

Efficient and Thermally Stable Cr3+‐Doped Phosphor Achieved by Cation Substitution: Plant Lighting Application

AbstractFar‐red phosphor‐converted light‐emitting diodes are receiving increasing attention as an essential component of the next‐generation plant‐growth lights. However, developing far‐red phosphors with high quantum efficiency, low thermal quenching, and suitable emitting wavelength is crucial and urgent. Herein, a new far‐red phosphor BaY2Ga3.9GeO12:0.1Cr3+ with high internal quantum efficiency (98%) and thermal stability (90.2%@423K) is obtained via the substitution of CaO8 with bigger BaO8 dodecahedrons, which is attributed to variations in the lattice environment of Cr3+. Meanwhile, controllable emission tuning from 780 to 708 nm and enhanced luminescence performance are achieved due to the cation substitution can reduce the production of Cr4+ and modulate the lattice occupancy of the Cr3+ ions, and the enhancement of metal‐ligand interactions resulting in the enhancement of the crystal field and the breaking of the forbidden d‐d transition of Cr3+. The proof‐of‐concept demonstration of the pakchoi lighting experiment reveals the great potential of BaY2Ga3.9GeO12:Cr3+ phosphor in stimulating plant growth and pushing the yield. These results demonstrate the feasibility of cationic substitution to optimize the optical performance of Cr3+‐doped phosphors, providing an alternative strategy for designing efficient far‐red light sources for plant lighting.

Full-Visible-Spectrum White LEDs Enabled by a Blue-Light-Excitable Cyan Phosphor.

Efficient blue-light-excitable broadband cyan-emitting phosphors may yield full-visible-spectrum white light-emitting diodes (WLEDs) with ultrahigh color rendering (Ra > 95). However, this requires closing the "cyan gap" in the 480-520 nm region of the visible spectrum, which is challenging. Herein, a well-performed cyan-emitting garnet phosphor Ca2LuAlGa2Si2O12:Ce3+ (CLAGSO:Ce3+) is reported. Under 430 nm excitation, the optimal CLAGSO:5%Ce3+ compound exhibits a broadband cyan emission (peak, 496 nm; bandwidth, 102 nm) with a high internal quantum efficiency of 85.6% and an excellent thermal resistance performance (69.1% at 423 K). Importantly, this as-prepared cyan-emitting phosphor provides sufficient cyan emission and enables filling the well-known so-called "cyan gap" between the blue LED chip and the commercial Y3Al5O12:Ce3+ (YAG:Ce3+) yellow phosphor. Impressively, a WLED device fabricated with the optimal CLAGSO:5%Ce3+ sample shows a low correlated color temperature (4053 K) and an ultrahigh color rendering index (Ra = 96.6), as well as an excellent luminous efficacy (74.09 lm W-1). These results highlight the importance of blue-excited broadband cyan-emitting phosphors in closing the cyan gap and enabling human-centric full-visible-spectrum warm WLED devices for high-quality solid-state lighting.

Reconstructing the Surface of K2SiF6:Mn4+ Phosphors toward Enhanced Moisture Resistance for White LED Applications.

The K2SiF6:Mn4+ (KSFM) phosphor featuring efficient ultranarrow red emissions is an outstanding candidate for white light-emitting diode (WLED) applications. However, poor moisture resistance seriously affects its application performance. In this study, a two-step surface reconstruction strategy is proposed to dramatically enhance the moisture resistance of commercially available KSFM phosphors, involving treatment with H2NbF7 and subsequent hydrothermal treatment. The modified KSFM phosphor exhibits a high internal quantum efficiency (IQE) of 98.9% after the two-step surface treatment. Meanwhile, nearly 100% of the initial emission intensity is retained for the modified KSFM phosphor even after aging in high temperature (85 °C) and high relative humidity (85% RH) environments for 6 days, in sharp contrast to only 18.6% retention for the original KSFM phosphor. The relative emission intensity of the modified KSFM remains at 98.9% even after being immersed in water for 6 h. Additionally, the phosphor-converted LED fabricated with the modified KSFM phosphor demonstrated excellent long-term stability, retaining up to 97.9% of initial luminous efficacy after aging under 85 °C and 85% RH conditions for 500 h. The moisture-resistance mechanism is elucidated on the basis of spectroscopic analysis as well as structural and compositional characterization of the phosphor surface layer, which can be attributed to the formation of a robust Mn4+-rare shell with high crystalline quality following this two-step surface treatment. The findings contribute to the performance improvements of KSFM phosphors for industrial applications.

Luminescence enhancement of near-infrared Cr3+ doped solid solution phosphor via Al3+ substitution for light-emitting diode applications

The luminescence enhancement of near-infrared (NIR) emissive material is critical in emerging applications. In this work, we have prepared an NIR-emitting K2NaSc1-x-yAlxF6:yCr3+ (denoted as KNS1-x-yAxF:yCr) solid solution phosphor via the introduction of Al3+, enhancing luminescence in a high-temperature solid-state reaction. The resultant solid solution phosphor exhibited a broad NIR emission band with a high internal quantum efficiency (IQE = 81.1 %) and an enhanced photoluminescence thermal stability (93 % at 423 K) under 432 nm excitation. When compared with the Al-free sample, the IQE and thermal stability are increased by 45.9 % and 22.4 %, respectively. The optimal Cr3+ and Al3+ doping content has been determined and a composition-optimized KNS0.70A0.25F6:0.05Cr phosphor is demonstrated by fabricating an NIR pc-LED device as a light source for light-emitting diode applications.

InP-based strain engineered InAs(Sb)/InAsPSb multiple quantum wells with tunable emission and high internal quantum efficiency enabled by Sb incorporation

A type I InAs(Sb)/InAsPSb strain engineered multiple quantum wells light emitting diodes system has been demonstrated. Tensile InAsPSb quantum barriers with a high degree of band offset (∆EC = 116–123 meV, ∆EV = 193–250 meV) were used to compensate for the high compressive strain of the InAs(Sb) quantum wells. The structure was grown on the n+-InAsxP1−x metamorphic buffer with a high degree of relaxation (98%), low surface roughness (0.69 nm), and low dislocation density. Through careful strain engineering design, the compressive strain of InAs(Sb) reaches 0.57%–1.52% without strain relaxation. The incorporation of Sb into the multiple quantum wells not only reduces the bandgap but also improves the interface quality by acting as an effective surfactant. Structural analysis reveals superior quality in InAsSb/InAsPSb multiple quantum wells compared to InAs/InAsPSb multiple quantum wells, demonstrating significantly reduced interface roughness and suppression of the Stranski–Krastanov growth mode. Room temperature electroluminescence measurements show a tunable emission wavelength ranging from 2.7 to 3.3 μm, accompanied by a narrow full width at half maximum value of 45 meV. Photoluminescence analysis indicates that the internal quantum efficiency of InAsSb/InAsPSb multiple quantum wells is 5.5%, which is 7 times higher than that of InAs/InAsPSb.

Thermal stable NaMgLaTeO6:Dy3+ double perovskite yellow phosphors for w-LEDs and latent fingerprint visualization

The novel Dy3+-doped NaMgLaTeO6 (NaMgLaTeO6:Dy3+) phosphors were produced through a high-temperature solid-state reaction. X-ray diffraction (XRD) analysis and Rietveld refinement manifest that the pure phosphor was committed to the space group (P21/m (11)) and features the double perovskite structure. The band gap (Eg) of the direct semiconductor NaMgLaTeO6 is calculated to be 2.065 eV. Under 388 nm excitation, the 4F9/2→6H13/2 energy level transition contributes to the maximum emission peak at 572 nm. Other properties of the phosphor include optimal concentration (x = 5 mol %), high thermal stability, activation energy (Ea = 0.31 eV), and internal quantum efficiency (IQE = 31.44 %). The relevant color coordinate of the white light emitting diode (w-LED) prepared by the phosphor is (0.298, 0.311). The features of the latent fingerprint (LFP) created by NaMgLaTeO6:Dy3+ can be clearly reflected on different surfaces. In summary, NaMgLaTeO6:Dy3+ phosphor has proven high potential in w-LEDs production and LFP detection.

Co-training machine learning enables interpretable discovery of near-infrared phosphors with high performance

Near-infrared (NIR) phosphors based on Cr3+ doped garnets present great potential in the next generation of NIR light sources. Nevertheless, the huge searching space for the garnet composition makes the rapid discovery of NIR phosphors with high performance remain a great challenge for the scientific community. Herein, a generalizable machine learning (ML) strategy is designed to accelerate the exploration of innovative NIR phosphors via establishing the relationship between key parameters and emission peak wavelength (EPW). We propose a semi-supervised co-training model based on kernel ridge regression (KRR) and support vector regression (SVR), which successfully establishes an expanded dataset with unlabeled dataset (previously unidentified garnets), addressing the overfitting issue resulted from a small dataset and greatly improving the model generalization capability. The model is then interpreted to extract valuable insights into the contribution originated from different features. And a new type NIR luminescent material of Lu3Y2Ga3O12: Cr3+ (EPW~750 nm) is efficiently screened, which demonstrates a high internal (external) quantum efficiency of 97.1% (38.8%) and good thermal stability, particularly exhibiting promising application in the NIR phosphor-converted LEDs (pc-LED). These results suggest the strategy proposed in this work could provide new viewpoint and direction for developing NIR luminescence materials.

Enhanced forward emission by backside mirror design in micron-sized LEDs.

Tiny InGaN micro-LEDs (μ-LEDs) play a pivotal role in emerging display technologies, particularly augmented reality (AR) applications. Achieving both high internal quantum efficiency (IQE) and efficient light extraction efficiency (LEE) is essential. While wet chemical etching can recover the IQE after dry etching, it alters the pixel shape, impacting optical properties and reducing the LEE. In this study, we overcome this issue by fabricating 1 μm thin-film-based μ-LED emitter arrays with a metallic backside mirror deposited on a patterned dielectric material around the μ-LED mesa. This concave mirror can be straightforwardly integrated into a thin-film LED process chain, and it redirects photons within the μ-LED structure, enhancing the LEE in the forward direction. Electro-optical measurements show a 2.1-fold improvement in light output within the ±15∘ emission cone compared to μ-LEDs with vertical sidewalls. These findings hold significant implications for μ-LED projection displays, where maximizing the overall efficiency and directionality is critical.

How to Make Semi‐Polar InGaN Light Emitting Diodes with High Internal Quantum Efficiency: The Importance of the Internal Field

How to Make Semi‐Polar InGaN Light Emitting Diodes with High Internal Quantum Efficiency: The Importance of the Internal Field

Optically optimization of thin film light-emitting diodes based on transfer matrix

The evolution of white LEDs, both organic and inorganic, has marked a transformative era in lighting technology known as solid-state lighting. This revolution is driven by electroluminescence, where electron-hole pairs recombine to emit light. While OLEDs have achieved high internal quantum efficiency, limited out-coupling efficiency remains a challenge. Improving light out-coupling efficiency is crucial for enhancing LED performance. This paper employs the Transfer Matrix Method to analyze the optical properties of OLEDs and aims to enhance light coupling, efficiency, and overall impact of LED and OLED technologies.

Impacts and effectiveness of sidewall treatment on the spatially resolved optical properties and efficiency enhancement for GaN-based blue and green micro-LEDs

InGaN-based micro-light-emitting diodes (micro-LEDs) are crucial for efficient full-color micro-displays, but suffer from severe degradation of external quantum efficiency (EQE) with size reduction. In this study, the impacts of chemical treatment on the sidewall condition and the EQE of the 10 μm InGaN-based blue and green micro-LEDs were demonstrated. The sidewall treatment can effectively alleviate the residual damage caused by dry etching and suppress the nonradiative recombination, facilitating the achievement of high internal quantum efficiency (IQE). Nevertheless, the sidewall light extraction of the micro-LEDs with smoother sidewall morphology after tetramethylammonium hydroxide (TMAH) treatment is lower than those with rough and prismatic sidewall surface. By utilizing microscopic hyperspectral imaging, the difference in chromatic properties between the inner region and the whole micro-LED caused by dry etching can hinder the stability of chromatic properties of InGaN-based blue micro-LEDs, which can be alleviated by sidewall treatment. The optimal duration for TMAH treatment is obtained as 10 min for both blue and green micro-LEDs, which is the consequence of the compromise between sidewall light extraction efficiency (LEE) and IQE, whereas the improvement of IQE by sidewall treatment for green micro-LEDs is less significant compared to that for blue ones, which can be attributed to the higher dislocation density and recombination via localized states of green InGaN micro-LEDs. This work demonstrates the evolution of IQE and LEE for blue and green micro-LEDs with different sidewall treatment strategies to achieving the ultimate EQE.

Polar solvent vapor annealing enhanced optoelectronic properties of solution-processed exciplex organic light-emitting diodes.

Exciplex organic light-emitting diodes (OLEDs) are widely utilized for their high internal quantum efficiency. Although solution-processed devices offer the advantages of simple operation and low cost, few studies have reported on the preparation of exciplex OLED devices using solution methods. This paper presents exciplex OLEDs produced between m-MTDATA and Bphen, fabricated using a solution method and optimized by a polar solvent vapor annealing (PSVA) treatment. Unlike other approaches applied to the transport layer, PSVA treatment was conducted on the exciplex-based light-emitting layer, resulting in successful enhancement of the photoelectric properties of both the light-emitting layer film and OLEDs, thereby achieving the anticipated objective. Optimized performance of exciplex OLEDs was achieved after the emission layer was PSVA treated for 20 min. The maximum luminescence intensity increased by a factor of ∼4 compared to a control device without PSVA treatment. An analysis of charge carrier mobility and impedance spectroscopy also indicated the inevitable presence of interface resistance when PSVA was applied to the exciplex emission layer. However, the total resistance (including interface and bulk resistances) was reduced to a minimum after a 20-minute PSVA treatment. Therefore, higher electron mobility and lower lighting voltage are obtained. The enhanced optoelectronic properties of exciplex OLEDs could be attributed to the PSVA treatment, which induced an alignment of polar molecules and enhanced electron mobility.

A Lu3Sc2Ga3O12: Eu3+ red-emitting phosphor with excellent optical properties and thermal stability was obtained by partially replacing Lu3+ with Gd3+ / Y3+

A novel red phosphor Lu3(1-x)Sc2Ga3O12: xEu3+(0 ≤ x ≤ 0.3) was successfully prepared by high temperature solid state method. The Lu2.4Sc2Ga3O12: 0.2Eu3+ phosphor shows strong high internal quantum efficiency and thermal stability with values of 64.79 % and 87.0 %, respectively. Based on Lu2.4Sc2Ga3O12: 0.2Eu3+ phosphor, the partial replacement of Lu3+ ions in the host by Gd3+ / Y3+ ions changes the local crystal field environment of Eu3+ ions, resulting in wonderful changes in the luminous center, and the luminous intensity at 593 nm is increased by 3.66 and 3.54 times, respectively. The decay time of Eu3+ ions is analyzed from the perspective of dynamics, and the reasons for the enhancement of luminescence after partial replacement of Lu3+ ions are discussed in detail from two aspects of phosphor structure and crystal field effect around Eu3+ ions. In addition, with the substitution of Gd3+ / Y3+ ions, the thermal stability of the sample is 90.3 %/89.4 % with excellent low thermal quenching. The thermal quenching mechanism is described by combining Debye temperature and activation energy. The sample also has a high internal quantum efficiency IQE=79.03 % / 78.24 %. Finally, under the excitation of 365 nm chip, the phosphors of Lu2.34Sc2Ga3O12: 0.2Eu3+, 0.02Gd3+ and Lu2.34Sc2Ga3O12: 0.2Eu3+, 0.02Y3+ synthesized R-LED device has extremely high color rendering index, Ra is 78.23/77.15 and color temperature is 1640.38 K/1642.97 K. The experimental results show that the Lu2.34Sc2Ga3O12: 0.2Eu3+, 0.02Gd3+ / Y3+ phosphors prepared has a wide application prospect in w-LED devices.