JOURNAL OF RARE EARTHS
·
2023
·
IF 4.9
Falin Zhang,Xiaoying Liang,Rongfei Wei,Hai Guo,Fangfang Hu
In this work, a group of Bi 3+ /Eu 3+ -doped SiO 2 –Al 2 O 3 -MCO 3 (M = Ca, Sr, Ba) glasses were fabricated through melt-quenching method. Their structure and photoluminescence characters were studied via X-ray diffraction (XRD), UV–Vis transmission spectra (TRS), excitation spectra, emission spectra and decay lifetimes. The XRD results show that no nano-crystal phase forms in glass matrix with different doping concentrations of Bi 3+ and Eu 3+ ions. Through regulating optical alkalinity value, the intensity of Bi 3+ ions increases and the peak position shifts to red wavelength. The Bi 3+ /Eu 3+ co-doped glasses show a blue-white-yellow-red luminescence by changing concentration of Eu 3+ ions. Energy transfer efficiency from Bi 3+ to Eu 3+ can reach as high as 10.54%. At 423 K, the emission intensity of 55SiO 2 –10Al 2 O 3 –35BaO-0.25Bi 2 O 3 (GBE0.5) is 31.1% of that at 308 K. Meanwhile, the activation energy of the glass matrix is 0.251 eV. All results suggest that these Bi 3+ /Eu 3+ co-doped glass samples possess potential application in LED field.
研究领域:
材料科学
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光学
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产品关联
DOI
高影响因子
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
·
2023
·Vol. 26
·期 35
·e202300556
·
IF 2.3
Quwei Ni,Jiansheng Huo,Qijian Zhu,Jianbang Zhou,Wenjie Sun,Yutong Huang,Chenggang Long,Qianming Wang
Graphical The Ca3Sc2Ge3O12:Cr3+ NIR emission garnet phosphor exhibits broadband emission peaking at 817 nm with a FWHM value of 128 nm. The developed phosphor presents balanced comprehensive performance and is suitable for NIR-LED application. The rapid growth in phosphor-converted near-infrared light-emission diodes (NIR-LEDs) has led to the development of NIR emitter with high efficiency, broadband emission and high thermal stability. In this work, an efficient broad NIR emission of Cr 3+ in novel Ca 3 Sc 2 Ge 3 O 12 (CSGO) garnet-based host was developed for the first time, which located at 700 to 1000 nm peaking at 817 nm with a broad bandwidth of ~128 nm. Such a broadband NIR emission originated from the preferential occupancy of Cr 3+ in Sc 3+ sites with weak octahedral field, which was manifested by the luminescence spectrum and decay behaviors. The Cr 3+ -doping concentration was regulated to achieve a good internal quantum efficiency (IQE) of 72.1 % and a fantastic thermal stability (at 423 K, sustained approximately 85 % of the initial intensity). The mechanism for concentration and thermal quenching was further investigated. Benefiting from the excellent luminescence features, a prototype NIR-LEDs was assembled via integrating the optimized samples with commercial blue InGaN LED chips, which exhibited a satisfactory photoelectric property and a brilliant performance in night vision. These results demonstrated the as-obtained sample to be a great potential candidate for NIR-LEDs.
研究领域:
材料科学
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光学工程
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2023
·
IF 3.6
Yufeng Du,Yuxin Li,Yixuan Zhao,Xinyu Zhang,Changlin Li,Ruiqi Yang,Zhequan Zou,Jingjing Lian,Jinyou Duan,Huihong Lin,Ruijin Yu
A new series of red luminescent Cd 2 MgTeO 6 : x Eu 3+ ( x = 0.5–50 mol%) phosphors was successfully synthesized through a high-temperature solid-phase reaction at 1000 °C. The synthesized phosphors were investigated for their phase purity, surface morphology , elemental distribution, and luminescence properties. Strong orange-red light emission (617 nm) was observed upon excitation at 398 nm, which was attributed to the electric dipole 5 D 0 - 7 F 2 transition of Eu 3+ . The optimal doping concentration was found to be x = 20 mol%. Concentration quenching mechanism was identified as the interaction of near-neighbor ions. The chromaticity coordinates of all the Cd 2 MgTeO 6 :Eu 3+ samples were found to be located in the red region and were almost the same. The Cd 2 MgTeO 6 : 20 mol%Eu 3+ phosphors exhibited an unusual thermal quenching behavior, maintaining 102% of the initial intensity, thus possessing excellent thermostability. Moreover, the manufactured white light diode demonstrated a good color rendering index ( R a = 89) with the coordinates of (0.344, 0.330) by the Commission International de L'Eclairage (CIE). Additionally, the Cd 2 MgTeO 6 : 20 mol%Eu 3+ phosphor was surface-functionalized with oleic acid (OA) (Cd 2 MgTeO 6 : 20 mol%Eu 3+ @OA) to aid in the identification of Level I-III fingerprint details with high resolution and contrast. Good visualization of the latent fingerprint (LFP) was observed on different substrates. Therefore, Cd 2 MgTeO 6 :Eu 3+ phosphors hold great promise for the visualization of w-LEDs and LFPs.
研究领域:
材料科学
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光学
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DOI
高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 32
·11010-11016
·
IF 6.4
Fan Chen,Xiao-Jun Wang,Wenhao Bai,Xuehu Zhang,Wen Hao,Changhua Zhang,Tongtong Xuan
Zero-dimensional (0D) lead-free halide perovskites are emerging as promising light-emitters, which can be applied as light conversion materials for illumination and display. Herein, we prepared a series of Sb3+:Rb2InCl5·H2O perovskites by a simple and efficient coprecipitation method. The Rb2InCl5·H2O perovskite gives no emission due to the parity-forbidden transition. When Sb3+ is doped into Rb2InCl5·H2O, radiative transition occurs. Under 365 nm excitation, the Sb3+:Rb2InCl5·H2O perovskites show an intense orange-red emission peak at 615 nm, ascribed to the 3P1 to 1S0 transition of Sb3+. The brightest luminescence of Sb3+:Rb2InCl5·H2O was achieved by doping 40%Sb3+, with a high photoluminescence quantum yield (PLQY) of 62.1% and an external quantum efficiency (EQE) of 30.2%. Furthermore, the prepared Sb3+:Rb2InCl5·H2O perovskite exhibits a distinguished thermal stability. At 150 °C, its PL intensity remains 68% of that measured at room temperature, with a high thermal activation energy of 0.184 eV. By combining Sb3+:Rb2InCl5·H2O with a blue-emitting Eu2+:BaMgAl10O17 (Eu2+:BAM) phosphor, bright warm-white light with a color rendering index of 88 and a correlated color temperature of 3242 K was achieved. To sum up, the prepared Sb3+:Rb2InCl5·H2O orange-red perovskites have the advantages of suitable excitation and emission peak positions, high emission intensity, high PLQY and EQE, excellent stability, and environmental friendliness, making them very attractive in the field of lighting and displays.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Pinyi He,Jianliang Bai,Guohui Yang,Fu Qin,Xinyu Wang,Xu Yu,Yongkang Yao,Xin Tang,Lili Ren
Phenylenediamine has become a classic material for synthesizing carbon dots (CDs) due to its nitrogen doping, conjugated aromatic structure, low cost, and easy availability. Typically, the CDs obtained from m-phenylenediamine (mPD), o-phenylenediamine (oPD) and p-phenylenediamine (pPD) exhibit fluorescence that follows a rule from blue to red. However, their photoluminescence quantum yield (PLQY) is low, and the spectral coverage is relatively small, which greatly limits their application and development in high-quality white LEDs. Herein, we selected a simple and environmentally friendly succinic acid (SA) to regulate the luminescence properties, which achieve unconventional luminescent behaviors with high PLQY values (68 %, 60 %, and 72 %) and wide spectral coverage. The PL emission of the obtained CDs followed the rule of pPD, mPD, and oPD from deep-blue to red, which is different from most previously reported results. Additionally, The SA molecules altered the polymerization structure and led to changes in the conjugated domain and surface C=O and –COOH groups, achieving this unconventional luminescence with high PLQY values. Finally, high-quality white LEDs were fabricated with the CIE coordinates of (0.34, 0.33), close to the (0.33, 0.33) of pure white light. R-CDs with an absolute PLQY value of up to 72 % were also used in bioimaging. We use the same small organic acid to regulate the phenylenediamine isomer and obtain CDs with fluorescence in different shift directions. This work will provide a new idea for luminescence regulation with high PLQY values and wide spectral coverage.
研究领域:
材料科学
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光学
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生物医学工程
✓ 已验证
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2024
·
IF 3.3
Fan Su,Zhiyue Liu,Jieyi Yuan,Li Hou,Tongyi Liang,Yifei Wang,Qinfang Zhang,Yong Dai,Shuhong Cao,Jingwen Chen
Mn 4+ -activated fluoride phosphors are promising luminescent materials for use in phosphor-converted white-light-emitting diodes (wLEDs). However, poor water resistance in high humidity environment, one of critical drawbacks of this type of phosphors, has limited their practical applications. To address this issue, we developed a new facile strategy to passivate the surface of phosphors by in situ constructing a dual Mn 4+ -rare protective layer using well-known aminocarboxyl complexants with mild reducibility and strong complexation property. Ethylenediamine tetraacetic acid (EDTA) was taken as a representative for the research in detail, and a typical Mn 4+ -doped fluorosilicate phosphor K 2 SiF 6 :Mn 4+ (KSFM) was selected to demonstrate the reliability of the proposed strategy. The surface passivation was achieved by simply dispersing KSFM in a saturated EDTA aqueous solution (KSFM-sEDTA) or a hydrofluoric acid solution containing a certain amount of EDTA (KSFM-EDTA), and then stirring for a short time at room temperature. The analysis results indicate that the dual Mn 4+ -rare surface layer is composed of a K 2 SiF 6 matrix shell and an organic coating of residual EDTA and/or its related compounds, and the layer constructed by Method 2 is more significant than that by Method 1. Both the luminescence performance and the water resistance of the passivated KSFM were greatly enhanced while the luminescence characteristics remained unchanged. When the water-eroded KSFM was re-treated with EDTA, the luminescence was dramatically restored due to removal of the manganese hydrolysates and repair of the crystal surface defects. The wLEDs assembled with KSFM-EDTA and KSFM-sEDTA phosphor exhibited intense white light with high luminous efficiency (LE, 170.61 lm/W and 162.51 lm/W), high color rendering index (CRI, 88.3 and 85.9), and low correlated color temperature (CCT, 3680 K and 3805 K), respectively. More importantly, the fabricated wLEDs retained high LE (90.6% and 88.6%) and no remarkable changes of CRI and CCT values after being aged at high temperature and humidity (85 °C, 85%) for 550 h, which are more superior to the wLED assembled with the pristine KSFM.
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
MATERIALS RESEARCH BULLETIN
·
2024
·
IF 5.3
Qin Wang,Rui Tian,Duo Zhang,Caiyan Huang,Jiani Shen,Wen Yang,Zhengliang Wang,Peizhi Yang
Herein, Rb 2 LiMF 6 :Mn 4+ (M= Al, In) phosphors were prepared by the non-equivalent doping of Mn 4+ . Mn 4+ in Rb 2 LiAlF 6 exhibits an ultra-intense zero phonon line (ZPL) detected at 627 nm, due to the highly-distorted symmetry. In contrast, the ZPL at 625 nm for Rb 2 LiInF 6 :Mn 4+ is very weak. The 2 E energy of Mn 4+ in Rb 2 LiAlF 6 (15,949 cm −1 ) is lower than that in all reported fluoride phosphors, which may be ascribed to the stronger polarization effect of Li + . Compared with Rb 2 LiInF 6 :Mn 4+ (5.07 %), Rb 2 LiAlF 6 :Mn 4+ (6.33 %) has a high internal quantum efficiency (IQE) values of 69.8 % and excellent thermal stability. The white LED packaged with Rb 2 LiAlF 6 :Mn 4+ (6.33 %) exhibits perfect performances with a high color render index (CRI = 92.3) and low color temperature (CCT =3875 K) as well as a high luminous efficiency (LE = 97.1 lm/W). Therefore, this work provides a promising red-emitting phosphor for high-quality white LEDs.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF FLUORESCENCE
·
2025
·
IF 3.1
Chen Dongxun,Lv Xulong,Liang Yanjie
In this work, Dy 3+ -doped Bi 2 SiO 5 nanoparticles with uniform spherical morphology and narrow size distribution have been successfully synthesized using a facile template-assisted approach. The effects of sintering temperature and Dy 3+ doping concentration on the phase composition, morphology, and luminescence properties of Bi 2 SiO 5 :Dy 3+ nanophosphor are systematically investigated through X-ray diffraction, scanning electron microscopy, and photoluminescence (PL) spectroscopy. X-ray diffraction results confirm that the synthesized Bi 2 SiO 5 :Dy 3+ nanospheres exhibit a pure tetragonal phase. Meanwhile, the phosphor particles are composed of monodisperse nanospheres with an average diameter of approximately 265 nm. Upon excitation at 388 nm, intense photoluminescence is noted in the blue ( 4 F 9/2 → 6 H 15/2 ) and yellow ( 4 F 9/2 → 6 H 13/2 ) spectral regions due to the characteristic emissions of Dy 3+ ions. Temperature-dependent PL spectra reveal that the optimized Bi 2 SiO 5 :2.5%Dy 3+ nanospheres maintain extraordinary luminescence thermal stability, retaining 81.0% of its emission intensity at 423 K compared to 303 K. The phosphor also showed remarkable color stability, with CIE chromaticity coordinates shifting minimally from (0.377, 0.413) at 303 K to (0.373, 0.407) at 423 K. This newly developed Bi 2 SiO 5 :Dy 3+ nanospheres exhibit commendable PL properties, enabling them as promising candidates for yellow phosphors in LEDs and display applications.
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
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 36
·1-14
·
IF 2.8
Yang Jian,Xie Chenglong,Zhao Lei
A newly synthesized orange–red-emitting phosphor, K 2 Sr(MoO 4 ) 2 :Sm 3+ , was produced for the first time through high-temperature solid-state synthesis methods. Detailed analysis was conducted on the phase purity, morphology, and luminescence properties of the synthesized phosphors. The K 2 Sr(MoO 4 ) 2 :Sm 3+ phosphors let forth orange–red light when excited at 403 nm because of the 4 G 5/2 → 6 H 9/2 transition. The optimal doping concentration of the K 2 Sr(MoO 4 ) 2 : x Sm 3+ phosphor was found to be x = 3 mol%. The chromaticity coordinates of K 2 Sr(MoO 4 ) 2 :3 mol% Sm 3+ were (0.617, 0.381) with a corresponding high color purity of 99.8%. This prepared w-LED exhibited an exceptional color rendering index (CRI) of 90, while maintaining a suitable correlated color temperature (CCT) of 5825 K and CIE color coordinates were (0.325, 0.327). Hence, K 2 Sr(MoO 4 ) 2 :Sm 3+ phosphors are desirable options for creating w-LEDs and lighting based on near-ultraviolet (NUV) chips. Their unique properties show significant potential for enhancing the performance of solid-state 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
Advanced Optical Materials
·
2024
·
IF 8
Xingyi He,Tianfeng Li,Zifan Liang,Renming Liu,Xia Ran,Xiaojuan Wang,Lijun Guo,Caofeng Pan
The emission of cyan light (470-500 nm) plays a vital role in the visible light spectrum and is essential for applications such as lighting, displays, and optical communication. Inorganic cesium lead bromide perovskite quantum dots (CsPbBr 3 PQDs) have made significant progress in the field of luminescence materials and devices, however, the lack of techniques to obtain highly emissive and stable cyan-emitting CsPbBr 3 PQDs has limited their device applications. Here, it is demonstrated that the complete surface passivation by treatment of didodecyldimethylammonium bromide (DDAB) and lead bromide, which can enhance the photoluminescence and stability of cyan emitting CsPbBr 3 PQDs. In particular, the photoluminescence quantum yield of CsPbBr 3 QDs can be greatly improved from 10.5% to 83.8%. Through an effective PMMA passivation, the obtained stable and bright CsPbBr 3 PQDs composite films as the cyan color converters can effectively emit the cyan light to fill the “cyan gap” of white light-emitting diode (WLED). The color rendering index value of such WLED is remarkably enhanced from 73.6 to 82.5. This study paves the way for the application of PQD color converters in the next generation of full-visible-spectrum WLED lighting.
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
·
2024
·
IF 5.1
Xinzhe Zhou,Li Guan,Huanrong Li
The white LEDs with high performance and excellent luminous quality is of high importance for developing the current lighting industry, and high thermally stable blue phosphors play a critical role in the preparation of white LEDs. Herein, we reported a facile way to obtain highly efficient blue Eu 2+ -doped celsian phosphor with excellent thermal stability by a phase transformation of Ba 2+ -exchanged SOD Zeolite strategy. The structure of phosphors changed from nepheline to celsian with the doping of Ba 2+ , and the maximum emission intensity blue-shifts from 550 nm to 450 nm under the excitation of 370 nm. The PLQY is determined to be 56 %, 96 % and 82 % for the phosphor with Ba 2+ doping concentration being 0, 1.49 and 1.86, respectively, and the luminescence intensity at 423 K is can be 80 %, 102 % and 93 % of its intensity at room temperature. Finally, the package of the LED device based on our yellow and blue phosphors together with the commercial red CaAlSiN 3 :Eu 2+ phosphor is constructed to show warm white light with the CCT of 3705 K and a high CRI of 97.7. This study provides a facile way for obtaining satisfactory phosphors for high-quality lighting.
研究领域:
材料科学
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光学工程
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产品关联
DOI
高影响因子
NANOTECHNOLOGY
·
2022
·Vol. 33
·期 46
·465202
·
IF 3.953
Xuan Yang,Shuling Zhou,Xinfeng Zhang,Linyi Xiang,Bin Xie,Xiaobing Luo
Quantum dots (QDs) are facing significant photoluminescence degradation in moisture environment. In QDs-silicone composites, the poor water resistance of silicone matrix makes it easy for water and oxygen molecules to erode QDs. To tackle this issue, we proposed a new QDs protection strategy by introducing short-chain silica precursors onto the QDs' surface, so that a dense silica passivation layer could be formed onto the QDs nanoparticles. Sol-gel method based on 3-aminopropyl triethoxysilane (APTES), 3-mercaptopropyl trimethoxysilane (MPTMS), and 3-mercaptopropyl triethoxysilane (MPTES) were adopted to prepare the uniform and crack-free QDs-silica glass (QD-glass). Because of the crosslinking of short-chain precursors, the formed silica glass possesses 38.6% smaller pore width and 68.6% lower pore volume than silicone, indicating its denser cross-linked network surrounding QDs. After 360 h water immersion, the QDs-glass demonstrated a 6% enhancement in red-light peak intensity, and maintained a stable full width at half maximum (FWHM) and peak wavelength, proving its excellent water-resistant ability. However, the conventional QDs-silicone composites not only showed a decrease of 75.3% in red-light peak intensity, but also a broadened FWHM and a redshifted peak wavelength after water immersion. QDs-glass also showed superior photostability after 132 h exposure to blue light. Red-light peak intensity of QDs-glass remained 87.3% of the initial while that of QDs-silicone decreased to 19.8%. And the intensity of QDs-glass dropped to 62.3% of that under 20 °C after thermal treatment of 160 °C. Besides, under increasing driving currents, the light conversion efficiency drop of QDs-glass is only one fifth that of QDs-silicone. Based on the QDs-glass, the white light-emitting diodes was achieved with a high luminous efficiency of 126.5 lm W−1 and a high color rendering index of 95.4. Thus, the newly proposed QD-glass has great significance in guaranteeing the working reliability of QDs-converted devices against moisture and high-power environment.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
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