JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Yanzhi Zhang,Xiang Guo,Minghao Zhang,Ruirui Cui,Jun Zhang,Chaoyong Deng
In this study, a Sm 3+ ion-doped double perovskite structure oxide was developed to obtain a novel Ca 2 GaNbO 6 : Sm 3+ orange-red phosphor, which has compensated for the lack of a red component in commercial wLEDs . The results of morphological features and phase structure have confirmed that the synthesized compound maintains the same structure as Ca 2 GaNbO 6, and that Sm 3+ successfully enters into the main lattice of Ca 2 GaNbO 6 . In terms of optical properties , the photoluminescence (PL) emission spectra monitored at 406 nm has the strongest emission peak at 599 nm and shows strong orange-red light. The spectral shapes of PL at different concentrations remain consistent without wavelength drift, and perform best when the concentration is 3 mol%, that is, the concentration quenching point is 3 mol%. The quenching phenomenon is believed to be mainly attributed to dipole-dipole (d-d) interaction. The Ca 2 GaNbO 6 : 0.03Sm 3+ phosphor shows excellent color purity (CP = 99.0 %) and low color temperature (CCT = 1664 K) in terms of chromaticity (CIE). In terms of heat resistance , the thermal stability of Ca 2 GaNbO 6 : 0.03Sm 3+ phosphor is 82.80 % (423 K). The internal quantum efficiency (IQE) is 34.4 %. In terms of applications, the wLEDs made of Ca 2 GaNbO 6 : 0.03Sm 3+ phosphor emits warm white light and exhibit excellent performance in color rendering index and correlated color temperature (CRI = 94.5, CCT = 3877 K). At the same time, Ca 2 GaNbO 6 : Sm 3+ phosphor shows good solubility in PVA . Research shows that Ca 2 GaNbO 6 : Sm 3+ phosphor has good performance in the fields of wLEDs and security ink.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
L. Yue,X.Z. Zheng,P.J. Xia,C. Wang,Y.F. Lei,M. Xu,W.B. Dai
Rare-earth (RE) and/or transition metal (TM) ions (co)doped phosphors have garnered much attention for promoting development in the fields of solid state lighting (SSL) and displays. It is a meaningful work to design high-quality phosphor via intelligent assembling from wide variety of compounds with RE/TM ions. Herein, the lanthanum borophosphate La 7 O 6 (BO 3 )(PO 4 ) 2 (LOBP) and Bi/Eu were selected as host and dopants for constructing the phosphor LOBP: Bi/Eu via solid phase synthetic method due to simple synthesis, chemical/thermal stability, rich cationic sites, appropriate bandgap, and controllable optical tuning from synergistic effect of cyan (Bi) and red (Eu) emissions, respectively. The structure and site occupations were analysed via XRD and Rietveld refinements , showing Bi 3+ ions were only resided in La 3+ sites within the monoclinic matrix (P2 1 /n) and appeared greater inclination towards the La sites with coordinate number ( CN ) = 8 as compared with CN = 7 due to the closer ion radius ratio. While Eu 3+ ions entered into the two distinct La sites with almost the same probability. The morphology and elemental mapping were obtained via SEM/EDS, exhibiting irregular particle shape with micron-level size, and the chemical composition met expectation. Through energy transfer (ET) from Bi to Eu under n -UV excitation, the adjustable photoluminescence (PL) from cyan traversing white and finally to red could be achieved. The concentration quenching for both singly- (Bi) and co-doped (Bi/Eu) phosphors were charged by the d-d interactions. Finally, the stable as-fabricated n -UV pumped w LED via coupling the composition-optimized white-emitting LOBP: 2%Bi, 7%Eu to a commercial 305 nm n -UV LED chip shows splendid performances.
研究领域:
材料科学
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光学工程
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2024
·Vol. 53
·期 9
·4325-4341
·
IF 3.5
P. J. Xia,X. Z. Zheng,L. Yue,Y. F. Lei,M. Xu,W. B. Dai
For further development of light sources, white light-emitting diodes (wLEDs) have attracted widespread attention as promising next-generation light sources fabricated via the combination of phosphors and LED chips. However, latent defects, such as chemical/thermal instability, low color rendering index (CRI) and high correlated color temperature (CCT), of current mainstream wLEDs seriously hinder their further large-scale implementation. Herein, in order to overcome these limitations, single-phase color-tunable gaudefroyite (Ca3Y(GaO)3(BO3)4 (CYGB)) tridoped with Bi3+/Tb3+/Eu3+ ions was synthesized for the first time and detailed characterisation was performed via high-temperature solid-state reaction and structural/spectral analyses, respectively. Radius difference percentage calculations and Rietveld refinements indicate that dopants occupy both Y3+ and Ca2+ sites but preferably the Y3+ site over the Ca2+ site due to the same valence state. Through subtly regulating the (co)doping contents and skillfully utilizing the energy transfer (ET) strategy from the allowed transition of blue light-emitting Bi to the forbidden transition of green/red light-emitting Tb/Eu, the color hue (including white light) of highly efficient PL can be easily tuned according to the need. Meanwhile, composition/content-optimized white light-emitting CYGB:2%Bi/10%Tb/12%Eu also shows splendid chemical/thermal stability. Finally, as a proof-of-concept experiment, the CYGB:2%Bi/10%Tb/12%Eu phosphor-converted wLED (pc-wLED) was fabricated and encapsulated via the up-to-date remote ‘capping’ method, which imparted attractive performances. Altogether, the stable CYGB:Bi/Tb/Eu phosphor is a promising candidate for application in lighting/display fields.
研究领域:
材料科学
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光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Zhongyuan Li,Chongyang Zhang,Bin Li,Cong Lin,Ye Li,Le Wang,Rong-Jun Xie
Low-dimensional lead-based perovskite materials have recently attracted extensive attentions for their diverse structures, unique optoelectronic properties and enhanced stability. However, the toxicity of lead, low photoluminescence quantum yield (PLQY) and complex preparation processes limit their practical applications. Herein, we present a simple room-temperature synthesis of orange-emitting lead-free perovskite derivative (NH 4 ) 2 SnCl 6 :Te phosphors with a large quantity at one time. By introducing Te 4+ ions with 5s 2 active lone pairs, (NH 4 ) 2 SnCl 6 :Te exhibits broadband emission peaked at 590 nm, a large full width at half maximum (FWHM) about 127 nm and a maximum PLQY up to 83.51%. Density functional theory calculations combined with comprehensive spectroscopic data reveal that the incorporated Te 4+ ions change the band structure and trigger the formation of Jahn-Teller-like self-trapped excitons (STEs) in [TeCl 6 ] 2− centers. In addition, (NH 4 ) 2 SnCl 6 :Te shows excellent ambient and thermal stabilities. Using (NH 4 ) 2 SnCl 6 :0.5%Te as an orange down-conversion material, highly stable wLEDs with a Commission Internationale de l’Eclairage (CIE) of (0.39, 0.38), correlated color temperature (CCT) of 3855 K, and color rendering index (CRI) of 83 are demonstrated. We expect these results to facilitate the development of low-cost, environmentally friendly and high-performance novel phosphors for future lighting and display technologies.
研究领域:
材料科学
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光学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Taifang Zhang,Dan Zhang,Zeyu Gao,Baoqi Ai,Valery F. Gremenok,Peng Wang,Chonggeng Ma
The advancement in the development of high-efficiency cyan-green emitting phosphors is pivotal for achieving high-color-quality full-visible-spectrum white light-emitting diodes (WLEDs). In this study, a series of novel cyan-green emitting BaLu 2 Al 3 ScGe 1- y Si y O 12 : x Ce 3+ (BLASGe 1- y Si y O: x Ce 3+ ) phosphors were successfully synthesized. X-ray diffraction analysis confirmed that all samples possess a typical garnet crystal structure, belonging to the Ia 3 ̅ d space group. The emission spectra of these BLASGe 1- y Si y O: x Ce 3+ phosphors effectively bridge the “cyan gap” within the 480–520 nm cyan-green emission region. Under 438 nm blue light excitation, the prepared BLASGO: Ce 3+ phosphor exhibits broad-band cyan-green emission with an emission peak at 504 nm and a full width at half maximum (FWHM) of 103 nm, thereby significantly enhancing cyan emission while preserving green emission. More importantly, by substituting Ge 4+ ions with smaller Si 4+ ions, the internal quantum efficiency (IQE) and thermal stability of the phosphor are markedly improved due to the highly symmetrical rigid structure. The optimized BLASSO: Ce 3+ phosphor demonstrates superior cyan-green emission performance with a high internal quantum efficiency of 93.28 % (an enhancement of 31.23 %) and thermal stability increased to 69.62 %. Based on the developed BLASSO: Ce 3+ cyan-green phosphor, a high-performance full-visible-spectrum WLED device was successfully fabricated, featuring a high color rendering index (CRI or R a , R a = 93.4) and a low correlated color temperature (CCT = 2814 K).
研究领域:
材料科学
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光电子学
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固态照明
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荧光粉化学
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发光材料
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2018
·Vol. 11
·期 7
·1090
·
IF 2.467
Man Yan,Guanghui Liu,Jiahao Wen,Yinlong Wang
The system NaLa(MoO4)2:Eu3+/Sm3+phosphors were prepared by solid-state reaction followed by heat treatment at 450–600 °C. As shown by X-ray powder diffraction, the phosphors had a body-centered tetragonal structure, high phase purity and high crystallinity. The photoluminescence measurements carried out under excitation at 464 nm indicated the main emission at about 615 nm corresponding to the electric dipole transition5D0→7F2of Eu3+, which agreed well with the emission wavelengths of the GaN-based blue LED chips. In NaLa(MoO4)2:Eu3+/Sm3+phosphors, Sm3+can efficiently transfer excitation energy to Eu3+, which resulted in a significant improvement of the fluorescence intensity, and the fluorescence intensity of the phosphors calcined at 550 °C maximized at the doping concentrations of Eu3+and Sm3+of 15.0 and 2.0 mol %, respectively. The decay curves and CIE (Commission Internationale de L’ Eclairage) coordinates of Sm3+or/and Eu3+doped phosphors were analyzed for the investigation of the energy transfer mechanism and color variation trend. Thus, NaLa(MoO4)2:Eu3+,Sm3+can be classified as a potential red-emitting phosphor for white light-emitting diodes (WLEDs).Keywords:luminescence properties;molybdate;red-emitting phosphor;energy transfer
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2022
·Vol. 15
·期 13
·4667
·
IF 3.748
Hongmei Liu,Junjie Tian,Honghao Sun,Qian Xu,Jinyan Yu,Qing Yao
Phosphors-in-glass (PiGs) regarded as a promising phosphor-converter for white light emitting diodes (WLEDs) is being researched widely. However, there are few reports on the effect of changing the shape of PiGs on the color rendering index (CRI) and heat dissipation of WLEDs. In this paper, gel casting with Isobam was first attempted in preparing special-shaped PiGs successfully. It exhibited that 76 wt.% was the optimum solid content based on the rheological properties of slurry and the shrinkage of green bodies. The sintering rate should be kept at a low speed and glass transition temperature (Tg) of glass powders must be higher than sublimation temperatures (Ts) of APS and Isobam. The CRI of PiGs was increased by about 27% after changing the shape of PiGs from cylinder to dome. Most importantly, operating temperature also reduced effectively the increase of the surface area of PiGs. Therefore, changing the shape of PiGs by gel casting with Isobam is a creative way for high-power WLEDs lighting.Keywords:phosphors-in-glass;white light emitting diodes;gel casting;color rendering index;heat dissipation
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
OPTIK
·
2023
·
IF 3.1
Yi Ling,Rongli Zhao,Xiang Guo,Ruirui Cui
A series of new red phosphors Na 2 BaCa(PO 4 ) 2 : x Eu 3+ was synthesized by the high temperature solid phase reaction method. Through employing X-ray diffraction, scanning electron microscope , photoluminescence spectroscopy, quantum efficiency curves and high-precision rapid spectrometers, a systematic investigation was conducted on the microstructure and optical characteristics of the material. The XRD analysis of Na 2 BaCa(PO 4 ) 2 : x Eu 3+ shows the sample to be a pure phase. The spectroscopic results show the presence of a red emission peak originated from 5 D 0 → 7 F 2 transition, and the quenching mechanism is attributed to interaction between nearest neighboring ions. Under 423 K, the fluorescence intensity of Na 2 BaCa(PO 4 ) 2 : 0.2Eu 3+ phosphor can still maintain 94.82 % of the value observed at 298 K, and the thermal activation energy Δ E reaches up to 0.3543 eV. The CCT of the LED packaged with Na 2 BaCa(PO 4 ) 2 : 0.2Eu 3+ was measured to be 4314 K, with the CIE coordinates (0.3658, 0.3600), which is very close to the point of standard white light source. The quantum efficiency of Na 2 BaCa(PO 4 ) 2 : 0.2Eu 3+ was measured to be 82.92 %. All results indicate that Na 2 BaCa(PO 4 ) 2 : 0.2Eu 3+ is suitable for WLED applications.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2023
·
IF 3.5
Jiachen Chen,Jin Li,Beining Li,Zhuocheng Chen,Xue Bai,Long Zhang,Jin He
The development of advanced luminescent materials is highly desirable for developing the energy-efficient lighting technology. However, it is still challenging to achieve stable full-color tuning in the same matrix upon a single-beam light excitation so as to ensure the high color stability and consistency. Herein, Eu 3+ /Eu 2+ /Tb 3+ co-doped sintered nanoporous glass via the dipping strategy is fabricated, which can emit blue, green and red emissions simultaneously by simply modifying the thermal treatment temperature. This full-color tuning is attributed to the dual roles of the thermal reduction of Eu 3+ to Eu 2+ in Al 2 O 3 -SiO 2 glass and simultaneous emissions of Eu 3+ /Eu 2+ /Tb 3+ activators. The densification of nanoporous glass via sintering could effectively decrease the amount of hydroxyl groups that present in the glass matrix, resulting in 5 times enhancement of the photoluminescence intensity and longer photoluminescence lifetime of rare earth (RE) ions. The thermal reduction of Eu 3+ to Eu 2+ is due to the reduction environment provided by Al 3+ ions in the Al 2 O 3 -SiO 2 glass. The energy transfer (ET) from Eu 2+ to Tb 3+ , Eu 2+ to Eu 3+ and Tb 3+ to Eu 3+ have been investigated in detail. Based on the ET mechanism, rational PL spectra design was demonstrated by varying the concentration of Eu 3+ ions in solution. The Color Correlated Temperature (CCT) and the Color Rendered Index (CRI) values of the white light emission glass are 7420 K (Cold-white emission) and 80.85, the temperature dependent photoluminescence (TDPL) analysis reflects the white light emission glass possesses high thermal stability and excellent thermal restorability. This facile fabrication and full-color tuning of Eu 3+ /Eu 2+ /Tb 3+ co-doped sintered nanoporous Al 2 O 3 -SiO 2 glass may provide a novel luminescent material for white-light emitting diodes (WLEDs) application.
研究领域:
材料科学
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光学工程
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 37
·17339-17345
·
IF 3.3
Yue Xu,Lubin Liu,Miaojun Xu,Wei Feng,Lili Wang,Xiaobiao Shan
At present, most white light-emitting diodes (WLED)s are modulated by mixing one or more kinds of quantum dots with a certain rare earth phosphor. However, because rare earth resources are limited, non-renewable, and expensive, it is urgent to develop a solution that does not rely on rare earths to solve the above problems. In this study, we used a hydrothermal method to fabricate nitrogen-doped graphene quantum dots (N:GQDs) using citric acid and piperazine as carbon and nitrogen sources. The N:GQDs exhibited blue fluorescence in solution under UV excitation at 365 nm, while exhibiting white luminescence in the solid state. The Commission Internationale de l’Enclairage coordinates and correlated color temperatures (CCTs) for the WLEDs based on N:GQDs are (0.28, 0.31) and 7469 K, respectively, and the WLEDs presented an outstanding color rendering index of up to 92.3, which can be used to realize the preparation of LED phosphors via single quantum dots for WLEDs, and is promising for use as backlights in lighting sources and displays.
研究领域:
材料科学
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光学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·Vol. 51
·期 27
·55119-55127
·
IF 5.6
Xiaomin Fan,Chaoyong Deng,Min Zhang
A novel Eu 3+ -doped Ca 2 LaNbO 6 (CLN) series phosphors were successfully synthesized using the high-temperature solid-state reaction method, and its properties were investigated. Phase structural analysis and morphological observation suggest successful doping of Eu 3+ ions into the host matrix without alteration of the original phase structure. The prepared phosphors exhibits strongest orange-red emission at 615 nm with 465 nm excitation, which corresponding to the energy level transition form 5 D 0 to 7 F 2 . The optimal doping concentration is 0.07 mol, and the concentration quenching is mainly caused by dipole-dipole interactions. For thermal stability, its intensity maintains the initial 87.14 % at 398 K, which indicats excellent thermal stability. The encapsulated WLEDs show favorable performance with a CTT 3606 K and a color rendering index (CRI) R a is 86. The packaged orange-red LEDs, when soldered onto a PCB board, can display the required letters, suggesting their potential application scenarios in the display field. The packaged orange-red LEDs soldered on PCB for information display. In addition, the excellent application performance in the field of anti-counterfeiting inks were invesitgated.
研究领域:
材料科学
·
光学材料
·
光子学
·
固态化学
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显示技术
·
安全印刷
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Jianyan Ding,Shuijing Huang,Hongling Zheng,Liting Huang,Peiru Zeng,Shanshan Ye,Quansheng Wu,Jiangcong Zhou
For realizing the full-visible-spectrum lighting of the white light-emitting diodes (WLEDs), in this work, a novel cyan light-emitting oxynitride based phosphor, Y 10 Si 3 Al 2 O 18 N 4 : Ce 3+ , has been successfully synthesized. Its crystal structure was refined to reveal that Y 10 Si 3 Al 2 O 18 N 4 contains multiple crystallographic Y sites and performs a tight crystal structure formed by the edge-sharing Y(O, N) 6 polyhedrons and (Si, Al) (O, N) 4 tetrahedrons. The luminescence properties of Y 10 Si 3 Al 2 O 18 N 4 : Ce 3+ demonstrate that the sample can be well excited by the near ultraviolet (NUV) LED chips and emits a broad-band cyan light with the full width at half maximum (FWHM) of 120 nm, which well replenishes the “cyan cavity”. The energy transferring between the multiple luminescent centers was investigated in detail through the TRPL spectra . Moreover, the temperature-dependent spectra of Y 10 Si 3 Al 2 O 18 N 4 : Ce 3+ was measured to assess its thermal stability. All of the results indicate the Y 10 Si 3 Al 2 O 18 N 4 : Ce 3+ to be a promising candidate for the application in full-visible-spectrum lighting of WLEDs.
研究领域:
材料科学
·
光学材料
·
固态照明
·
荧光粉化学
·
发光学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）