Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 36
·11220-11226
·
IF 6.641
Binbin Su,Maxim S. Molokeev,Zhiguo Xia
To discover new narrow-band green-emitting phosphors is a challenge for backlighting light-emitting diodes (LEDs) used in liquid crystal displays (LCDs). The synthesis and optical properties of Cs3MnBr5 are demonstrated herein. The intrinsic Mn2+ luminescence without concentration quenching leads to intense green emission at 520 nm with narrow full width at half maximum of 42 nm and high photoluminescence quantum yield (PLQY) of 49% under the excitation at 460 nm. When a small amount of Zn2+ is introduced into Cs3MnBr5, the luminescence intensity decreases slightly. However, the thermal stability of Cs3MnBr5 is improved from 82% to 87% with the intensity values at 423 K compared to that at 298 K. The white LED device fabricated using Cs3Mn0.96Zn0.04Br5 (green) and K2SiF6:Mn4+ (red) phosphors with a blue LED chip exhibit a high luminous efficiency (107.76 lm W−1) and wide color gamut (101% National Television System Committee standard (NTSC) in Commission Internationale de L’Eclairage (CIE) 1931 color space), demonstrating its potential application in wide color gamut LCD backlights.
研究领域:
材料科学
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光学材料
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固态照明
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荧光粉化学
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LED技术
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 9
·2596-2603
·
IF 6.641
Xiaohui Li,Bojana Milićević,Miroslav D. Dramićanin,Xiping Jing,Qiang Tang,Jianxin Shi,Mingmei Wu
Single-component white light phosphors with a broad and full color spectrum are urgently required to overcome residual problems with commercial phosphors. In this paper, we describe how Eu3+, as the dopant of Sr3ZnTa2O9 (SZT), plays an important role in structural modulation (including structural order–disorder and intrinsic oxygen defects), as demonstrated by electronic structural calculations and systematic experiments. Furthermore, 5D0 → 7F2 emission of Eu3+ provides the red component of the emission spectrum and increases the color rendering index of SZT:Eu3+ phosphors. Consequently, the resulting phosphor SZT:10%Eu3+ shows significantly enhanced emission intensity, and its broadband emission covers the entire visible region from 400 nm to 720 nm. A fabricated LED device using a near-ultraviolet 370 nm chip coated with a single-component, the SZT:10%Eu3+ phosphor, shows warm white emission with a high color rendering index (Ra = 82).
研究领域:
材料科学
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光子学
·
固态化学
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光学材料
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发光材料
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LED技术
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 40
·14971-14981
·
IF 8.067
Shuai Huang,Mengmeng Shang,Minliang Deng,Yu Yan,Peipei Dang,Jun Lin
Efficiently modulating the site occupation of activators has important implications in the design of color-tunable phosphors. In this paper, we report a series of novel Sr3Sc4O9:xEu phosphors. The activators (Eu2+) selectively occupy multiple cationic sites (Sr1–3 and Sc1–4) in the Sr3Sc4O9 matrix with the increase of doping concentration, thus achieving the modulation of emission color from deep-red to white to green. The structure-dependent luminescence mechanism is investigated in detail. The PL spectrum of the Sr3Sc4O9:0.06Eu phosphor upon blue light excitation exhibits an asymmetrically broad deep-red emission band peaking at 688 nm with a FWHM ≈ 100 nm, which clearly overlaps with the absorption curves of red-phytochrome (Pr) and far-red-phytochrome (Pfr). The photoluminescence quantum yield (PLQY) is significantly improved from 2.7% to 19.18% by adopting a double-reduction strategy. The full-visible-spectrum white emission of Sr3Sc4O9:0.01Eu is achieved when excited by UV light. A full-spectrum white LED with Ra = 86 and CCT = 5040 K was packaged with a single-component white emission Sr3Sc4O9:0.01Eu phosphor. All the results suggest the utilization potential of multifunctional Sr3Sc4O9:xEu phosphors in agricultural and full-spectrum general lighting.
研究领域:
材料科学
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光学材料
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固态照明
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发光与荧光粉
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LED技术
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无机化学
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2019
·
IF 3.355
Dayu Huang,Peipei Dang,Yi Wei,Biao Bai,Hongzhou Lian,Qingguang Zeng,Jun Lin
Recently, much attention has been attracted on the optical properties based on the phosphors for LED light. A near Ultraviolet (n-UV) and blue chip activated phosphor of CaLi 6 La 2 Nb 2 O 12 :Bi 3+ , Mn 4+ is synthesized by a traditional SSR method. Phase purity and lattice structure of the crystal have been confirmed and investigated by XRD, Rietveld refinement, FE-SEM and TEM. The luminescence performances of the series phosphors are investigated by diffuse reflection spectra (DR), Raman scattering spectra, steady-state PL spectra and the measurement of lifetime., the CaLi 6 La 2 Nb 2 O 12 :Bi 3+ , Mn 4+ exhibits emission peaked at ∼466 and ∼711 nm Under excited at 312 nm. The Dq, B and C are calculated to estimate the nephelauxetic effect of Mn 4+ in [NbO 6 ] octahedral lattice. The coordinate shifting could be controllable through the energy transfer Bi 3+ →Mn 4+ , which can be verified by PL spectra and decay lifetimes. Finally, by coating the blend of red CaLi 6 La 2 Nb 2 O 12 :0.03Bi 3+ ,0.015 Mn 4+ and Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce 3+ ) phosphors onto the blue LED chip, a LED device with good performances ( x = 0.36, y = 0.36, CRI = 86.6, CCT =4220 K) can be achieved. Hence, CaLi 6 La 2 Nb 2 O 12 :Bi 3+ , Mn 4+ is a good material of red emission.
研究领域:
材料科学
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光学材料
·
发光材料
·
固态化学
·
光子学
·
LED技术
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 10
·3672-3681
·
IF 7.393
Sheng Wu,Puxian Xiong,Xiaoqi Liu,Yubin Fu,Quan Liu,Yang Chao,Quan Dong,Yuanyuan Li,Weiwei Chen,Yan Chen,Zhijun Ma,Mingying Peng
In this study, a blue fluorescent material Sr3Y(BO3)3:Bi3+ was synthesized by the high temperature solid-state reaction method. The corresponding structural characteristics, concentration and temperature dependent luminescence characteristics of Sr3Y(BO3)3:Bi3+ and the LED device performances were systematically studied. At different excitation wavelengths in the range of 340–375 nm, the photoluminescence (PL) region can be adjusted from green (CIE: (0.2524, 0.4063); Peak: 511 nm) to blue (CIE: (0.1936, 0.1236); Peak: 415 nm). The best excitation peaked at ∼370 nm, which well matches with the emission of a commercial near-ultraviolet (NUV) light-emitting diode (LED) chip. The thermal quenching experiment was performed, and the activation energy was calculated as 0.23 eV. At high temperature, the Sr2.55Y(BO3)3:0.45Bi3+ phosphor presented good thermal stability (79.99% of RT emission intensity at 420 K). LED devices (chip: 370 nm) using the Sr2.55Y(BO3)3:0.45Bi3+ phosphor as a fluorescent material showed excellent electroluminescence performance. Under a driving current of 20 mA, the devices showed CIE coordinates of (0.3842, 0.3980), a correlated color temperature (CCT) of 4053 K and a high color rendering index (Ra) of 91.6. This work demonstrates that Sr3Y(BO3)3:Bi3+ is a promising NUV excited blue fluorescent material which shows advantage in white light-emitting diodes for solid-state lighting.
研究领域:
材料科学
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光电子学
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发光材料
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固态照明
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LED技术
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2019
·Vol. 103
·期 3
·1773-1781
·
IF 3.094
Xian Yang,Yu Zhang,Xuejie Zhang,Jian Chen,Haisen Huang,Dongsheng Wang,Xirong Chai,Gening Xie,Maxim S. Molokeev,Haoran Zhang,Yingliang Liu,Bingfu Lei
The red emission with suitable peak wavelength and narrow band is acutely required for high color rendering index (CRI) white LEDs without at the cost of the luminous efficacy. Herein, the Li 2 Ca 2 Mg 2 Si 2 N 6 :Eu 2+ red phosphor was prepared with facile solid-state method using Ca 3 N 2 , Mg 3 N 2 , Si 3 N 4 , Li 3 N, and Eu 2 O 3 as the safety raw materials under atmospheric pressure for the first time, which shows red emission peaking at 638 nm with full width at half maximum (FWHM) of 62 nm under blue light irradiation and becomes the desired red phosphor to realize the balance between luminous efficacy and high CRI in white LEDs. The morphology, structure, luminescence properties, thermal quenching behavior, and chromaticity stability of the Li 2 Ca 2 Mg 2 Si 2 N 6 :Eu 2+ phosphor are investigated in detail. Concentration quenching occurs when the Eu 2+ content exceeds 1.0 mol%, whereas high-temperature photoluminescent measurements show a 32% drop from the room-temperature efficiency at 423 K. In view of the excellent luminescence performances of Li 2 Ca 2 Mg 2 Si 2 N 6 :Eu 2+ phosphor, a white LEDs with CRI of 91 as a proof-of-concept experiment was fabricated by coating the title phosphor with Y 3 Al 5 O 12 :Ce 3+ on a blue LED chip. In addition, the potential application of the title phosphor in plant growth LED device was also demonstrated. All the results indicate that Li 2 Ca 2 Mg 2 Si 2 N 6 :Eu 2+ is a promising red-emitting phosphor for blue LED-based high CRI white LEDs and plant growth lighting sources.
研究领域:
材料科学
·
光电子学
·
固态照明
·
荧光粉化学
·
LED技术
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2018
·Vol. 101
·期 12
·5451-5460
·
IF 2.956
Zaifa Pan,Ruiping Wang,Weiqiang Li,Haiqin Wu,Jiacheng Chen,Yifan Zheng
Structural modification is an important means to induce redshift of Ce 3+ emission in garnet phosphor. We intend to design and synthesize garnet oxynitride compounds which combine attributes of rigidity inherited from garnet structure and of high covalence characteristic of oxynitride compounds. However, impurity phase usually occurs in the nitridation of garnet phosphor, due to the low solubility of nitrogen in oxides. We herein exploit the cooperative cation substitution strategy to facilitate the incorporation of nitrogen in Y 3 Al 5 O 12 . It is found that partial substitution of Y 3+ -Al tet 3+ pairs by Mg 2+ -Si 4+ pairs can diminish the phase instability caused by the replacement of Al tet 3+ -O 2− by Si 4+ -N 3− . A novel pure garnet phase oxynitride phosphor MgY 2 Al 3 Si 2 O 11 N:Ce 3+ with a higher substitution content of N has been obtained and the successful incorporation of N in the garnet phosphor is confirmed by the Rietveld refinements of XRD, XPS, and TEM. The emission and excitation spectra indicate that the blue-light-excitable MgY 2 Al 3 Si 2 O 11 N:Ce 3+ phosphor exhibited a bright yellow-orange emission peaking at 570 nm, which is redshifted by 28 nm when compared to YAG:Ce 3+ . The garnet oxynitride phosphor exhibit excellent thermal stability with high quantum efficiency and is a promising candidate for warm white LED.
研究领域:
材料科学
·
光电子学
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固态化学
·
发光材料
·
LED技术
✓ 已验证
DOI
高影响因子
PHYSICA B-CONDENSED MATTER
·
2021
·
IF 2.436
Xiaojian Pan,Lihong Bao,Luomeng Chao,Kefu Chao,Zizhong Liu
CaNb 2 O 6 :Tb 3+ green phosphors have been successfully fabricated via the traditional solid-state synthesis, where the nanocrystalline TbB 6 is used as efficient activator. The doping effects of nanocrystalline TbB 6 on the phase composition, the microstructure and photoluminescence of as-prepared phosphors were characterized by means of Rietveld refinement XRD , FESEM and photoluminescence measurements. As a result, all the synthesized CaNb 2 O 6 :Tb 3+ phosphors are composed by the single phase of CaNb 2 O 6 . The photoluminescence (PL) spectroscopy shows that the maximum emission intensity occurred when the nanocrystalline TbB 6 doping concentration is x = 0.06. Moreover, this phosphor keep the emission intensity remains about 43.3% of 300 K when its emission temperature increase to 423 K. Additionally, the white LED is fabricated by mixing present green phosphor with commercial blue and yellow phosphors, showing a white LED with the color temperature of 5152 K. On the basis of above mentioned, Ca 0·94 Nb 2 O 6 :0.06TbB 6 phosphor can be applied as a potential green phosphor for high-performance white LED.
研究领域:
材料科学
·
光学材料
·
发光材料
·
固态化学
·
LED技术
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry C
·
2015
·
IF 4.772
Lili Wang,Hyeon Mi Noh,Byung Kee Moon,Sung Heum Park,Kwang Ho Kim,Jinsheng Shi,Jung Hyun Jeong
Dual-mode excitation properties were introduced in Sm3+ doped Sr2CaMoO6 prepared by a high temperature solid state reaction technique. Two ways are available to generate white light in the single-component phosphor activated by Sm3+ ions. Warm white light can be obtained from Sr1.995Sm0.005CaMoO6 phosphor pumped by 380 or 411 nm excitation energy. The full visible spectral emission of the single-phase phosphor comes from the high and low level emission lines of Sm3+ ions as well as the intrinsic luminescence of MoO6 group. It is also competitive as yellow-emitting phosphor for blue pumped white LEDs and gives three emission bands at 567, 603, and 650 nm, presenting yellow luminescence upon 466 nm radiation. The 650 nm red emission band corresponding to 4G5/2 → 6H9/2 transition of Sm3+ can make its color rendering index better. The excellent photoluminescence of Sr2CaMoO6 is related to the partial tilting CaO6 octahedral and the lowered symmetry were confirmed by General Structure Analysis System. Band gap of Sr2CaMoO6 estimated from the diffuse reflection spectra and also calculated by CASTEP mode shows its semiconducting character. All the results show that the Sr2–xSmxCaMoO6 phosphors have considerable potential for applications in near UV LED or pumped by blue LED chip.
研究领域:
材料科学
·
光学材料
·
光子学
·
固态化学
·
发光材料
·
LED技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）