Materials Advances
·
2024
·
IF 5.2
Wasim Ullah Khan,Waheed Ullah Khan,Haris Zaman,Ayaz Mahsud,Dilfaraz Khan,Salim Ullah Khan,Shuakat Khan,Yueli Zhang
Correlated color temperature (CCT) is widely used to describe the chromaticity of white light sources, although chromaticity is only two-dimensional, and the distance from the Planckian locus is typically absent. Herein, a novel single-phase Ca3YAl3B4O15:Tm3+,Dy3+,Eu3+, an emerging white-emitting phosphor with good optical properties and thermal-stability, is produced, and the practical calculation methods to calculate the chromaticity-shift (ΔE) and Duv value for color-quality are also demonstrated, making it a good contender for possible use in LEDs. The incorporation of Eu3+ into Ca3YAl3B4O15:0.015Tm3+,0.08Dy3+ resulted in attractive warm-white light with CCT declining from 4635 K to 3065 K. The Ca3YAl3B4O15:Tm3+,Dy3+,Eu3+ exhibited excellent thermal stability (I@400 K = ∼93%). The Ca3YAl3B4O15:Tm3+,Dy3+,Eu3+-based WLED exhibits satisfactory parameters of high Ra (89.9) and low-CCT (3065 K). Additionally, this article offers useful mathematical strategies for calculating Duv over a wide-range of chromaticity, from 2000 to 6000 K in CCT and from −0.002 to 0.014, which strongly matches the range in an American National Standards Institute (ANSI) standard. For the first time, white light with minimized thermal-quenching, improved CRI, and color quality has been used in near-UV chip-excited WLEDs.
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
OPTICAL MATERIALS
·
2024
·
IF 3.8
Renjie Jiang,Jie Chen,Mingqin Li,Yanna Tian,Shiji Shen,Xuan Yang,Yanru Tang,Yan Sun,Hui Lin,Shengming Zhou
Ce: YAG- Al 2 O 3 composite ceramics are regarded as highly promising materials for laser illumination application due to their high luminous efficacy and thermal stability. Nevertheless, the Ce: YAG ceramics exhibit limited color rendering index (CRI) for indoor lighting due to their low red emission component. In this study, we synthesized high-performance Ce, Mn-doped (Y, Tb) 3 Al 5 O 12 –Al 2 O 3 composite ceramic phosphors via a vacuum solid-state sintering method. It was observed that the introduction of Mn 2+ ions created a second luminescence center with an emission peak centered at 580 nm. As the Mn 2+ concentration increased, the emission peak redshifted from 580 nm to 591 nm, leading to a significant enhancement in the color rendering index of the ceramics. The cross-energy transfer between Tb 3+ and Mn 2+ , Ce 3+ ions augmented the absorption and conversion of blue light by the ceramics, thereby reducing the correlated color temperature greatly. Based on these findings, ceramics with a Ce 3+ concentration of 3 at% and a Mn 2+ concentration of 4 at% exhibited the highest CRI values (81.3 and 75.6) under both laser excitation and LED excitation, establishing them as strong candidates for achieving high color rendering in white LED/LD illumination applications.
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
Science Advances
·
2023
·Vol. 9
·期 15
·
IF 13.6
Heng Zhang,Zhequn Huang,Min Ding,Qixiang Wang,Yilin Feng,Zhenghong Li,Shan Wang,Lei Yang,Shuai Chen,Wen Shang,Jian Zhang,Tao Deng,Hongxing Xu,Kehang Cui
Energy-efficient, healthy lighting is vital for human beings. Incandescent lighting provides high-fidelity color rendering and ergonomic visual comfort yet is phased out owing to low luminous efficacy (15 lumens per watt) and poor lifetime (2000 hours). Here, we propose and experimentally realize a photon-recycling incandescent lighting device (PRILD) with a luminous efficacy of 173.6 lumens per watt (efficiency of 25.4%) at a power density of 277 watts per square centimeter, a color rendering index (CRI) of 96, and a LT70-rated lifetime of >60,000 hours. The PRILD uses a machine learning–designed 637-nm-thick visible-transparent infrared-reflective filter and a Janus carbon nanotube/hexagonal boron nitride filament to recycle 92% of the infrared radiation. The PRILD has higher luminous efficacy, CRI, and lifetime compared with solid-state lighting and thus is promising for high–power density lighting.
研究领域:
能源技术
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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
Nanophotonics
·
2016
·Vol. 5
·期 4
·565-572
·
IF 4.333
Wei Chen,Kai Wang,Junjie Hao,Dan Wu,Jing Qin,Di Dong,Jian Deng,Yiwen Li,Yulong Chen,Wanqiang Cao
In this research, we have developed an approach by incorporating quantum dots (QDs) with red emission into mesoporous silica microspheres through a non-chemical process and obtained luminescent microspheres (LMS). Owing to the lattice structure of LMS, QDs were effectively protected from intrinsic aggregation in matrix and surface deterioration by encapsulant, oxygen and moisture. The LMS composite has therefore maintained large extent luminescent properties of QDs, espe-cially for the high quantum efficiency. Moreover, the fabricated white light emitting diode (WLED) utilizing LMS and YAG:Ce yellow phosphor has demonstrated excellent light performance with color coordinates around (x = 0.33, y = 0.33), correlated color temperature between 5100 and 5500 K and color rendering index of Ra = 90, R9 = 95. The luminous efficiency of the WLED has reached up to a new record of 142.5 lm/W at 20 mA. LMS provide a promising way to practically apply QDs in lightings and displays with high efficiency as well as high stability.
研究领域:
材料科学
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光学工程
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2021
·Vol. 51
·期 2
·645-654
·
IF 4.39
Qinghong Meng,Guoying Zhao,Qi Zhu,Xiaodong Li,Xudong Sun,Ji-Guang Li
Synergistic doping of the metastable Gd3Al5O12:Ce garnet with a Ca2+/Hf4+ pair and Sc3+ to form Gd2.97−xCaxHfxScyAl3O12:0.03Ce (x = 0.5–2.0, y = 0.0–1.5, x + y = 2.0) solid solution was conducted for the structural stabilization and photoluminescence manipulation. The site selection of Ca2+/Hf4+/Sc3+ dopants and the effects of doping on the crystal structure, local coordination, band structure and Ce3+ luminescence were revealed in detail with the results of XRD, Rietveld refinement, TEM, and UV-Vis/photoluminescence spectroscopy. A decrease in Ca2+/Hf4+ and an increase in the Sc3+ content were observed to shrink the lattice, widen the bandgap of the garnet host, red-shift the excitation/emission wavelength, broaden the emission band and shorten the fluorescence lifetime of Ce3+. The spectral changes were rationalized by considering the local coordination and crystal field splitting of the Ce3+ 5d energy level. Application of typical Gd0.97Ca2Hf2Al3O12:0.03Ce (x = 2.0, y = 0) cyan and Gd2.47Ca0.5Hf0.5Sc1.5Al3O12:0.03Ce (x = 0.5, y = 1.5) greenish-yellow phosphors in w-WLED lighting produced low correlated color temperatures of ∼3842 and 3514 K, high color rendering indices of ∼88 and 93 and favorable luminous efficacies of ∼32.9 and 14.7 lm/W under the excitation of 395 nm n-UV and 450 nm blue LED chips, respectively.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Optical Materials
·
2022
·Vol. 10
·期 21
·2201081
·
IF 10.05
Ranyun Wu,Yingmeng Liu,Sanlue Hu,Pengfei Fu,Zewen Xiao
Recently, A 2 BX 6 -type halide perovskite variant phosphors have been applied for white light-emitting diodes (LEDs) due to their superior photoluminescence properties, excellent stability, and low-cost solution-processability. However, the reported white LEDs, particularly the all-A 2 BX 6 white LEDs, exhibit insufficient color rendering due to the shortage of red light. In this work, through a rational material design, a red-emitting perovskite variant Cs 2 PtCl 6 phosphor is developed. The synthesized Cs 2 PtCl 6 powders exhibit a relatively narrow bandgap of 2.91 eV and an intrinsic broadband red emission centered at 670 nm, which is attributed to the triplet self-trapped excitons associated with the Jahn−Teller-distorted [PtCl 6 ] 2− octahedra in the excited state. Using Cs 2 PtCl 6 as the red phosphor component, an all-A 2 BX 6 white LED is constructed, achieving a standard white light with a Commission Internationale de l'Eclairage chromaticity coordinate of (0.33, 0.33), a correlated color temperature of 5318 K, and a record high color rendering index of 90. This work represents a significant step toward the application of A 2 BX 6 perovskite variant phosphors for solid-state lighting.
研究领域:
材料科学
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光学工程
·
发光材料
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2020
·
IF 2.779
Lin Chen,Jingxia Zheng,Qin Du,Yongzhen Yang,Xuguang Liu,Bingshe Xu
Orange-emissive carbon dot (o-CDs) phosphors were prepared to reduce the correlated color temperature and increase the color rendering index of carbon dots (CDs)-based white light-emitting diode (WLED) devices. 2,7-dihydroxynaphthalene was selected as the carbon source and N, N -dimethylformamide was used as the nitrogen source to synthesize nitrogen doped o-CDs with wide and double-peak emission spectrum . Warm WLED device was designed by taking o-CDs as phosphors and excited by a UV chip. Results showed that o-CDs have a fluorescence quantum yield of 26.03%, their emission spectrum is wide enough to range from 480 to 680 nm, and show good photo and thermal stability, which is quite suitable for warm WLED phosphors. o-CDs based WLED device emits warm white light with a color coordinate of (0.41, 0.39) and a correlated color temperature of 3330 K. Compared with the current warm WLEDs devices based on CDs, their color rendering index reaches a high level, which is 91. This study provides a new idea for broadening the application of CDs in warm WLEDs that used in indoor lighting.
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
MATERIALS RESEARCH BULLETIN
·
2021
·
IF 4.641
Yanzhen Yin,Zhen Wang,Maochen Zhu,Yue Zhang,Jianhong Li,Chao Dou,Shijia Sun,Bing Teng,Yang Che,Degao Zhong
A single-phased warm white phosphor of α-Sr 2 V 1.98 P 0.02 O 7 : 0.5 % Eu 3+ 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 PO 4 3− /VO 4 3− , the emission intensity of VO 4 3− and the energy transfer efficiency of VO 4 3− →Eu 3+ 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-Sr 2 V 1.98 P 0.02 O 7 : 0.5 % Eu 3+ 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.
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
Optical Materials Express
·
2017
·Vol. 7
·期 9
·3065-3076
·
IF 2.591
Wanlu Zhang,Wu Yang,Ping Zhong,Shiliang Mei,Guilin Zhang,Guoping Chen,Guoxing He,Ruiqian Guo
The spectral optimization for maximizing limited luminous efficacy (LLE) of correlated color temperature (CCT) tunable white light-emitting diodes (LEDs) with two, three and four color perovskite quantum dots (QDs) excited by a blue chip was investigated under the constraint of designated ultrahigh color rendering index (CRI) and color quality scale (CQS). The results show that high quality white lights with CRIs of 96-97, CQSs of 95-96, and LLEs of 243-225 lm/W at CCTs of 2700 K to 6500 K could be realized by the QDs-converted white LEDs (QD-WLEDs) using a blue chip and different combinations of perovskite quantum dots. The luminous efficacies of QD-WLEDs are expected to reach 114 to 122 lm/W at CCTs of 2700 K to 6500 K, if the radiant efficiency of a blue chip is 60% and the real PLQY values of perovskite QDs are 75%. These results demonstrate that perovskite QD-based LEDs are expected to be promising in next generation display and lighting technologies.
研究领域:
光学工程
·
材料科学
·
照明技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2023
·
IF 3.6
Nan Ma,Zongjie Zhang,Wei Li,Xiaoyong Huang
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 Ce 3+ -activated CaLu 2 HfScAl 3 O 12 (CLHSA) garnet phosphor for application in blue-light-excited full-spectrum warm-white LEDs. CLHSA:Ce 3+ 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 Ce 3+ ions is found to be 1 mol%. Upon 408 nm excitation, the optimal CLHSA:1%Ce 3+ 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%Ce 3+ cyan phosphor, commercial YAG:Ce 3+ yellow phosphor and commercial CaAlSiN 3 :Eu 2+ 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%Ce 3+ phosphor is promising for application in blue-chip-pumped full-visible-spectrum warm-white LEDs with high CRI values.
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
CHEMISTRY-A EUROPEAN JOURNAL
·
2025
·
IF 3.7
Yueyue Wu,Lan Liu,Zifan Li,Jiayi Xie,Zixin Wang,Guo Fang,Keyan Li,Zhenhui Tao,Xin Li,Fei Xiu,Juqing Liu
Graphical With the synergy of Mn 2+ and ODA codecoration, CDs with ultrabroadband and efficient yellow fluorescence in the solid state were synthesized through a simple one-step solvothermal process. These synthetic phosphors exhibit a production yield of 80%, an FWHM of 98 nm, and a solid-state quantum yield up to 62.8%, allowing for high-CRI white LEDs in green and health lighting. Exploiting environment-friendly and efficient phosphors is crucial to constructing high-quality and sustainable white light-emitting devices. Here, we demonstrate a facile and high-yield approach to synthesize Mn 2+ /octadecylamine (ODA)-codecorated carbon dots (CDs) with ultrabroadband and efficient yellow fluorescence in the solid state. The dots are prepared from anhydrous citric acid (CA), 1-ODA, and manganese acetate through a simple one-step hydrothermal process, with a production yield of 80%, a full width at half maxima (FWHM) of 98 nm, and a solid-state quantum yield up to 62.8%. Utilizing the synthetic CDs powder as a phosphor to directly coat on a blue light-emitting chip, the device exhibits warm white emission, with a high color rendering index (CRI) of 88, correlated color temperature (CCT) of 4215 K, and Commission International de l'Éclairage (CIE) coordinates of (0.33, 0.31), endowing great potential applications in green and health lighting.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
·
2023
·
IF 3.6
Jiawen Li,Jiawen Wang,Feifei Huang,Youjie Hua,Shiqing Xu,Ruoshan Lei
In pursuit of healthy lighting, the exploitation of high-quality Eu 2+ -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 Rb 3 GdSi 2 O 7 : Eu 2+ phosphor is successfully synthesized via a high-temperature solid-state reaction method. The crystal structure of Rb 3 GdSi 2 O 7 is found to be hexagonal, belonging to space group P6 3 /mmc. The Rb 3 GdSi 2 O 7 : Eu 2+ 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, Rb 3 GdSi 2 O 7 : Eu 2+ 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 Rb 3 GdSi 2 O 7 : Eu 2+ yellow-green phosphor and commercial BaMgAl 10 O 17 : Eu 2+ 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 Rb 3 GdSi 2 O 7 : Eu 2+ in NUV-converted warm WLEDs, which may promote the development of high-color-quality healthy lighting.
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
危险品化学品经营许可证（带存储）