JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Sai Lin,Yinzi Cheng,Chun Lin,Jiali Fang,Weidong Xiang,Xiaojuan Liang
In this report, carbon nanodots (CDs) with tunable full-color emission were successfully synthesized by a solvothermal method. By changing the carbon source (p-phenylenediamine or o-phenylenediamine) and the concentration, green, yellow, orange and red CDs (GCDs, YCDs, OCDs and RCDs) were successfully fabricated. As the concentration of the starting materials was increased, the emission peak was red-shifted. The shifted peaks showed strong intensity and an obvious color change. This concentration-dependent effect was attributed to the reabsorption phenomenon. Carbon source was critical in determining the fluorescence properties and the quantum yield (QY) of full-color CDs was high. The CDs also presented a distinct pH sensitivity. The PL intensity of RCDs showed linear decreases over decreasing pH from 11 to 4 and from 4 to 2. Fluorescent oil carrying CDs was successfully applied for various purposes such as anti-counterfeiting, information encryption and storage purposes. An RCD film was successfully fabricated that could improve the correlated color temperature and color rendering index of white light-emitting diodes.
研究领域:
材料科学
·
光学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2018
·Vol. 102
·期 4
·1822-1831
·
IF 2.956
WeiHui Song,XueYan Chen,LiMing Teng,ZhiGang Zheng,Jun Wen,FangFang Hu,RongFei Wei,LiPing Chen,Hai Guo
Single-composition Ba 2 Y 2 Si 4 O 13 :Bi 3+ ,Eu 3+ (BYSO:Bi 3+ ,Eu 3+ ) phosphors with color-tunable and white emission were prepared by conventional high temperature solid-state reaction method. The structural and luminescent properties of these phosphors were thoroughly investigated through X-ray diffraction, photoluminescence, and decay curves. BYSO:Bi 3+ phosphors show two excitation peaks at 342 and 373 nm, and give two emission peaks at 414 and 503 nm, respectively, indicating that there are two sites of Bi 3+ in BYSO. The energy transfer from Bi 3+ to Eu 3+ was investigated in detail. Varied hues from blue (chromaticity coordinate [0.219, 0.350]) to white (0.288, 0.350) and orange-red light (0.644, 0.341) can be generated by adjusting the content of Eu 3+ . Pure white light emission (0.311, 0.338) can be obtained under the excitation of 355 nm in BYSO:3%Bi 3+ ,20%Eu 3+ phosphor. Besides, BYSO:Bi 3+ ,Eu 3+ phosphors exhibit distinct thermal quenching properties, whose emission intensity at 473 K is 82.6% of that at 298 K. Our results indicate that BYSO:Bi 3+ ,Eu 3+ may be applied as conversion phosphors for n-UV-based W-LEDs.
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 ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Pu Fan,Zefeng Xu,Qi Luo,Zongjie He,Yuhui Chen,Qiqi Miao,Cong Huang,Xiaoguang Liu,Ling Li
Phosphor-converted white LEDs are realized by combining blue InGaN chips with yellow and red emitting materials. Due to the lack of efficient red phosphor materials, we can design a broadband yellow phosphor material containing as many red components as possible. We found an abnormal broadband yellow-emitting Ba 2 CaB 2 Si 4 O 14 :Eu 2+ borosilicate phosphor inspired by natural minerals, which has been synthesized by traditional high temperature solid-state method. The structural information and photoluminescence characteristics of Ba 2 CaB 2 Si 4 O 14 :Eu 2+ were characterized in detail, and applied to the fabrication of white LED devices. Excited by near ultraviolet light at 365 nm, it displays a wide emission band from 400 to 800 nm centered on the 595 nm peak. White LED devices were fabricated by physically mixing the yellow phosphor Ba 2 CaB 2 Si 4 O 14 :Eu 2+ and synthesized blue phosphor BaMgAl 10 O 17 :Eu 2+ with 365 nm UV chip as excitation. The correlation color temperature (CCT) value and the chromaticity coordinates of the fabricated WLED devices were found to be 5522 K and (0.3293, 0.3036) respectively. In conclusion, Ba 2 CaB 2 Si 4 O 14 :Eu 2+ has great potential in the preparation of near UV excited white LEDs.
研究领域:
材料科学
·
光电技术
·
光子学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Xuemei Yao,Yatuan Ma,Xiya Miao,Shulei Li,Yufeng Du,Yun Cheng,Yue Yang,Xianchao Du,Huajuan Deng,Huiling Geng,Ruijin Yu
The propensity of carbon dots (CDs) to undergo significant self-quenching in the solid state, whether due to excessive resonance energy transfer or direct molecule collision, has significantly limited their application in light-emitting diodes (LEDs). However, incorporating electron-deficient boron atoms, guanidine functional groups, and boron hydroxyl groups proves advantageous in forming a hydrogen bond structure network. This network effectively suppresses the self-quenching phenomenon observed in solid CDs, thereby enhancing their potential for use in LEDs. Therefore, on this basis, a series of multicolor tunable solid-state fluorescent CDs were obtained, and their formation mechanism was discussed. The structure and morphology of the prepared series of multicolor tunable CDs were also characterized. The photoluminescence quantum yield (PLQY) of B-CD, Y-CD, and R-CD is 34.3 %, 23.7 %, and 20.5 %, respectively. The prepared series of CDs were used to successfully package the red, blue, and yellow monochromatic LEDs. By adjusting the ratio of CDs of different colors, a single matrix white-LEDs (w-LEDs), two primary colors w-LEDs, and the full-carbon-based w-LED of three primary colors are also obtained. The correlated color temperature of the above three w-LEDs is 7277, 3957, and 5040 K, the Color Rendering Index is 88, 91, and 92, and color coordinates are (0.302, 0.319), (0.376, 0.355), and (0.344, 0.354), respectively. It is demonstrated that CDs are a promising material in the solid-state lighting field.
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
CHEMICAL PHYSICS LETTERS
·
2017
·
IF 1.815
Baochen Wang,Yan-gai Liu,Zhaohui Huang,Minghao Fang
A series of Ca 3 Si 2 O 4 N 2 :Ce 3+ , Tb 3+ phosphors were synthesized and their phase composition and luminescence properties were investigated. Results showed that an efficient energy transfer occurred between the Ce 3+ and Tb 3+ ions. The thermal stability of the Ce 3+ emission was dramatically enhanced upon Tb 3+ doping. The mechanism was attributed to a shift of the configuration coordinate and an increased energy barrier for thermal quenching, which resulted from the enhanced rigid structure of the host. Finally, a white light emitting diode lamp was fabricated, which exhibited excellent properties. These results indicate that Ca 3 Si 2 O 4 N 2 :Ce 3+ , Tb 3+ can serve as promising blue-green emitting phosphors for w-LEDs.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Yanzhi Zhang,Xiaoxu Deng,Ruirui Cui,Xiang Guo,Jun Zhang,Chaoyong Deng
In order to obtain efficient single-phase co-doped phosphors with excellent luminescence properties under near-ultraviolet excitation, Ca 3 Gd 2 Si 3 O 12 : x Dy 3+ (CGSO: x Dy 3+ ) and Ca 3 Gd 2 Si 3 O 12 :0.08Dy 3+ , y Sm 3+ (CGSO:0.08Dy 3+ , y Sm 3+ ) phosphors were effectively manufactured using the classical high-temperature solid-phase method. The phase structure, morphology and XPS test results of the phosphor all show that the Ca 3 Gd 2 Si 3 O 12 (CGSO) material has been successfully synthesized, and Dy 3+ and Sm 3+ ions have been successfully doped into the matrix lattice. Under 362 nm illumination, the PL spectra of CGSO:0.08Dy 3+ , y Sm 3+ phosphor revealed that the typical peak intensity of Dy 3+ ions declined as the amount of Sm 3+ ions increased, whereas the distinctive peak intensity of Sm 3+ ions achieved its maximum at y = 0.07. As Sm 3+ doping grows larger, the fluorescence lifetime shortens, signifying the occurrence of transferring energy among Dy 3+ and Sm 3+ ions, with a maximum efficiency of 81 % being attained. The Ca 3 Gd 2 Si 3 O 12 :0.08Dy 3+ , y Sm 3+ phosphor demonstrates a commendable thermal stability of 90.17 %, with adjustments to the Sm 3+ concentration revealing the potential to yield warm white light, as evidenced by both CIE chromaticity coordinates and CCT measurements. In addition, compared with the phosphor containing only Dy 3+ , the LED assembled with CGSO:0.08Dy 3+ , y Sm 3+ phosphor containing Sm 3+ ions and 365 nm LED chip emits warmer white light with lower color temperature, which confirms the application value of CGSO:0.08Dy 3+ , y Sm 3+ phosphor in the domain of solid-state lighting.
研究领域:
材料科学
·
光学
·
固体照明
✓ 已验证
产品关联
DOI
高影响因子
LUMINESCENCE
·
2018
·Vol. 33
·期 2
·438-442
·
IF 1.671
Ting Li,Zhijun Wang,Panlai Li,Shuchao Xu,Qiongyu Bai,Zhiping Yang
A novel tunable red emitting phosphor LiBaB 9 O 15 :Sm 2+ /Sm 3+ , Li + with broad excitation band was synthesized by a high temperature solid-state method. Luminescence properties were investigated in detail by luminescence, X-ray photoelectron spectroscopy (XPS) spectra and CIE chromaticity coordinates. XPS data confirmed that there were Sm 3+ in LiBaB 9 O 15 :Sm 3+ and Sm 2+ /Sm 3+ in LiBaB 9 O 15 :Sm 2+ /Sm 3+ , respectively. Spectral property of LiBaB 9 O 15 :Sm 3+ , LiBaB 9 O 15 :Sm 3+ /Sm 2+ and LiBaB 9 O 15 :Sm 2+ , Li + presented that the excitation band of Sm 3+ widened and the excitation band of Sm 2+ ranged from 350 to 450 nm. And the red light color is tunable with changing Li + concentration. The results indicated that LiBaB 9 O 15 :Sm 2+ /Sm 3+ , Li + may be promising red phosphor for white light emitting diodes.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Nan Ma,Wei Li,Balaji Devakumar,Zongjie Zhang,Xiaoyong Huang
White light-emitting diodes (LEDs) are widely used in lighting and display devices, and the exploration of phosphors with excellent luminescence performance and good stability is the key to the development of white LEDs. In this work, we reported novel near-UV-excited green-emitting Ca 2 LuHf 2 (AlO 4 ) 3 :Ce 3+ ,Tb 3+ garnet phosphors with efficient Ce 3+ → Tb 3+ energy transfer. The CLHA:Ce 3+ ,Tb 3+ green phosphors were successfully synthesized by a high-temperature solid-state method, and the phosphors were characterized by X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, elemental mapping, photoluminescence excitation and photoluminescence spectra, the Commission International de I’Eclairage (CIE) chromaticity coordinates, quantum efficiency and temperature-dependent emission spectra. Due to the spin-allowed 4f → 5d transition of Ce 3+ ions, the CLHA:Ce 3+ ,Tb 3+ phosphors exhibited a strong broad excitation band in the 300–470 nm near-ultraviolet (near-UV) range. Under 408 nm excitation, the CLHA:Ce 3+ ,Tb 3+ phosphors showed strong green light with emission center at 543 nm. The mechanism of energy transfer from Ce 3+ to Tb 3+ ions was attributed to quadruple-quadruple interaction. Impressively, the internal quantum efficiency and external quantum efficiency of the optimal CLHA:0.02Ce 3+ ,0.5Tb 3+ green phosphors were measured to be 77.1% and 55.8%, respectively. Finally, using the CLHA:0.02Ce 3+ ,0.5Tb 3+ phosphors as green-emitting color converter, a near-UV-pumped white LED device was fabricated, and under 80 mA driving current the LED device demonstrated bright warm-white light with high color rendering index (93.7), low correlated color temperature (3574 K), CIE chromaticity coordinates (0.3922, 0.3633), and high luminous efficacy (29.35 lm/W).
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
JOURNAL OF LUMINESCENCE
·
2023
·
IF 3.6
Yanting Liu,Yanzhu Wang,Lili Meng,Qi Pang,Hua Yao,Qian Chen,Sidi Ye,Yanting Li,Minyi Zheng
Herein, we successfully obtained Ho 3+ and Ag + -codoped Cs 2 NaBiCl 6 halide double perovskites (DPs) via a hydrothermal method , which exhibit orange-red broadband self-trapped excitons (STE) emission and visible (Vis) and near-infrared (NIR) narrow band emission attributed to Ho 3+ f-f transition, under 360 nm excitation. Compared to the single Ho 3+ -doped sample, the Vis PL intensity of the codoped sample was increased by nearly 13.8 times, and an enhanced photoluminescence quantum yield (PLQY) of 87.45 % was achieved. The PL enhancement is attributed to the partial substituting of Na + with Ag + , leading to an efficient STE emission, and the more energy transition from STE to Ho 3+ . Moreover, the synthesized phosphor exhibits good stability in thermal and atmospheric environments. White light-emitting diode (WLED) is fabricated by employing Cs 2 Na 0·997 Ag 0·003 Bi 0.935 Ho 0.065 Cl 6 on near-ultraviolet (n-UV) LED chips, achieving a color rendering index (CRI) of 95.0 and correlated color temperature (CCT) of 3814 K. Anti-counterfeit patterns and the application for night vision monitoring were also discussed. This study inspires the designing of high-quality phosphors of rare earth-doped DPs and expands the multi-domain luminescence applications of halide DPs.
研究领域:
材料科学
·
光学工程
·
稀土材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF FLUORESCENCE
·
2024
·
IF 2.6
Zha Jiahao,He Chongjun,Chen Fangzhou,Wang Hongwei,Dong Biao,Liu Lijuan,Xia Mingjun,Deng Chenguang,Li Qian,Lu Yuangang,Chen Huiting
Oxide matrix red-emitting phosphors are deemed as excellent color converters for white light emitting diodes (WLEDs) and laser diodes (LDs). Manganese-doped MgAl 2 O 4 powder was synthesized by a solid-state reaction method at different sintering temperatures. Microstructure shows that grain size is mainly in the range of 0.2–5 μm, and grain agglomeration occurs with increased sintering temperature. XPS analysis indicates that the doped Mn ion exhibits a valence state of + 4 within the MgAl 2 O 4 matrix. The diffraction peak of the phosphors is shifted by the sintering temperature, which affects lattice constant. Upon excitation by 300 nm ultraviolet light, the samples emit asymmetric broadband red light within the range of 620–720 nm, attributed to Mn 4+ ion’s transition from 2 E g to 4 A 2g states. With the increasing temperature, the main emission peak shifts from 677 nm to 650 nm, ascribed to the change in energy level ( 2 E g ) resulting from the reduction of Al 2 O 3 phase. Crystal field theory confirmed that Mn 4+ ions are within a strong crystal field environment created by MgAl 2 O 4 matrix. By affecting particle size and crystallinity, the sintering temperature influences the fluorescence lifetime of the Mn 4+ ion. Notably, these red-emitting phosphors exhibits remarkable thermal stability as their emission intensity remains approximately at 58% of initial intensity even at elevated temperature (435 K). Consequently, Mn 4+ : MgAl 2 O 4 red-emitting phosphors with high thermal stability render them promising candidates for WLED applications.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2020
·Vol. 7
·期 18
·3371-3378
·
IF 5.958
Yang Zhou,Xiaoming Wang,Cuiping Wang,Tian Zhang,Yonggang Wang,Fan Dou,Huan Jiao
A novel red fluoride phosphor BaNbF7:Mn4+ was synthesized via the conventional co-precipitation method. The structure and luminescence properties of BaNbF7:Mn4+ were investigated and discussed under various conditions. The BaNbF7:Mn4+ phosphor shows strong ZPL emission intensity at about 630 nm under ultraviolet (UV) and blue light excitation. It originated from the highly distorted Mn4+ octahedral coordination environment in the C3v group symmetry surrounding. A WLED fabricated with a blend of YAG:Ce3+ and the BaNbF7:Mn4+ phosphor exhibits a low color temperature (CCT = 3715 K) and a high color rendering index (Ra = 81.2), indicating its potential for application as a red phosphor for WLEDs.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2017
·Vol. 5
·期 34
·8828-8835
·
IF 5.256
Yibo Chen,Kuanglun Wu,Jin He,Zhengbin Tang,Jianxin Shi,Yiqin Xu,Zhao-Qing Liu
The rational and delicate synthesis of Mn4+ activated red-emitting oxide phosphors with high photoluminescence quantum yield (PLQY) and photo-stability for developing high-quality w-LEDs still remains a great challenge. Herein, we demonstrate a simultaneous ion co-substitution design strategy to synthesize a red-emitting Lu3Al5O12:Mn4+,Mg2+ garnet phosphor delicately with the assistance of MgF2. The Mn4+ activated garnet phosphor exhibits superior moisture resistance properties and high PLQY (ca. 72.41%), which emits a bright and narrow-band red light peaking at ∼670 nm due to the 2E–4A2 spin-forbidden transition of Mn4+ upon UV excitation. Remarkably, MgF2 as a charge compensator & flux can not only accelerate the solid state reaction, but also greatly improve the emission intensity. Furthermore, by employing the as-prepared Lu3Al5O12:Mn4+,Mg2+ as a red component, we fabricate a warm w-LED with a high color rendering index (Ra = 81.4) and low color temperature (CCT = 4766 K) based on a UV chip and commercial blue and yellow phosphors.
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）