INORGANIC CHEMISTRY
·
2020
·
IF 4.825
Dan Zhang,Xiangting Zhang,Zhengce An,Rujia Dong,Zhan Shi,Yanhua Song,Haifeng Zou
Here, the crystal structure, phase analysis, site occupancy, and luminescence properties of NCMP:Eu2+,Tb3+,Mn2+ have been studied for the first time. Under 335 nm ultraviolet excitation, the NCMP:Eu2+ phosphors show narrow-band blue emission. In addition, we discuss the reason for a continuous red shift for the emission spectra of NCMP:xEu2+ by raising the x value. The efficient ET processes of Eu2+ → Tb3+ and Eu2+ → Mn2+ were investigated by the luminescence spectra and decay curves. The ET efficiencies reach 92.58% at y = 0.15 for NCMP:0.01Eu2+,yTb3+ and 99.85% at z = 0.15 for NCMP:0.01Eu2+,zMn2+ phosphors, respectively. The efficient energy transfer processes greatly improve the quantum efficiency, luminous intensity, and thermal stability. Bright green and red emissions can be realized through changing the related ratio of Eu2+, Tb3+, and Mn2+. In addition, the excellent performance of the prepared white LED lamps utilizing a 385 nm chip combined with our prepared NCMP:Eu2+,Tb3+/Mn2+ phosphors indicates that NCMP:0.01Eu2+,yTb3+ and NCMP:0.01Eu2+,zMn2+ phosphors can be potential green and red phosphors for white LEDs.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
LUMINESCENCE
·
2023
·Vol. 38
·期 2
·208-215
·
IF 2.9
Hui Wang,Lingling Wang,Meihua Wu,Minghao Fang,Zhaohui Huang,Xin Min
This paper reports a sequence of a Ca 3 YAl 3 B 4 O 15 :xEu 3+ red phosphor prepared using a high-temperature solid-state reaction. At the excitation of 396 nm, the samples emitted intense red emission centred at ~623 nm, which could be attributed to the 5 D 0 → 7 F 2 transition of the Eu 3+ ion. The results showed that the optimum Eu 3+ doping concentration of Ca 3 YAl 3 B 4 O 15 :Eu 3+ phosphor was x = 80 mol%, and the concentration quenching mechanism of Ca 3 YAl 3 B 4 O 15 :Eu 3+ red phosphor belonged to the exchange coupling between Eu 3+ ions. The Commission Internationale de l'éclairage (CIE) coordinates and colour purity of Ca 3 Y 0.2 Al 3 B 4 O 15 :0.8Eu 3+ were calculated as (0.6375, 0.3476) and 95.5%, respectively. Moreover, the red emission of the obtained phosphor Ca 3 YAl 3 B 4 O 15 :0.8Eu 3+ exhibited a low thermal quenching behaviour with an intensity retention rate of 92.85% at 150°C. The above results manifest that the Eu 3+ -activated Ca 3 YAl 3 B 4 O 15 phosphor is predicted to be a promising red luminescent component for white light-emitting diodes.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
LUMINESCENCE
·
2019
·Vol. 35
·期 1
·138-143
·
IF 1.691
Xiaoshuang Li,Lite Zhao
Energy storage phosphors with millisecond period afterglow that compensate for the diming time of alternating current light-emitting diodes (AC-LEDs) have promising application. To obtain a persistent luminescence (PersL) white colour in AC-LEDs, we focussed on a red afterglow with short period phosphorescence. Ca 4 Ti 3 O 10 forms a type of perovskite-related Ruddlesden–Popper phase structure. Doping Pr 3+ ions into Ca 4 Ti 3 O 10 , an ideal red PersL was obtained. X-ray diffraction and element analysis demonstrated that our target samples were crystallized well. Steady-state and afterglow luminescence properties were investigated in detail. Notably, the PersL intensity was dependent on various excitation wavelengths. By measuring three-dimensional thermoluminescence spectra, we found that the trap depths showed a continuous distribution and that the shallowest trap contributed to the millisecond afterglow. Two PersL mechanism models were used to elucidate the electron charging and de-trapping processes under UV or blue light activation.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Haifeng Zhe,Zongqi Chen,Jie Li,Yayun Zhou,Qiang Zhou,Zhengliang Wang
Modulating phase transitions in fluoride phosphors is essential for developing high-performance luminescent materials, but conventional extreme-condition methods often cause structural damage and efficiency degradation. This study proposes a thermal-pressure coupling strategy to achieve reversible Fm-3m to P6 3 mc phase transformation in K 2 SiF 6 :Mn 4+ under mild conditions. The distorted [MnF 6 ] 2- octahedra in the P6 3 mc enhance d-orbital hybridization, significantly reinforcing the zero-phonon line (ZPL). Consequently, luminescence intensity increases by 1.54-fold, external quantum efficiency (EQE) improves by 29.5%, and 90% intensity is retained at 200 °C. LED devices employing P6 3 mc phosphor sheets achieve a color rendering index (Ra) of 84.4 and luminous efficacy of 138.2 lm/W while maintaining stable Ra and correlated color temperature (CCT) across 20 - 300 mA driving currents. Notably, device temperature at 200 mA operation is reduced by 30% compared to conventional methods. This work establishes an effective approach for optimizing fluoride phosphors and advancing high-performance lighting technologies.
研究领域:
材料科学
·
光学材料
·
固态照明
·
发光二极管
·
无机荧光粉
✓ 已验证
产品关联
DOI
高影响因子
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
ACS Applied Optical Materials
·
2022
·
IF 0
Hongshi Zhang,Chaojie Li,Jiyou Zhong,Jun Wen,Weiren Zhao
The near-infrared (NIR) phosphor-converted light-emitting diode (pc-LED) is an emerging portable light source and has multifunctional applications based on spectroscopic technology. Nevertheless, it is still difficult to develop broadband NIR materials with strong resistance toward thermal quenching. In this work, a thermally robust broadband NIR phosphor NaGaP2O7:Cr3+ was reported, which has an emission peak located at 793 nm, and the emission spectrum covers 650–1100 nm with a full width at half-maximum (fwhm) of 115 nm. The emission intensity at 150 °C was surprisingly maintained as 85.45% of that at 25 °C, indicating an outstanding ability to resist thermal quenching. A systematic investigation of aspects such as structural rigidity, the band gap of the host, and the electron phonon coupling effect was carried out to understand the mechanism of thermally robust luminescence in this material. Finally, the NaGa0.94Cr0.06P2O7 NIR phosphor and 450 nm InGaN LED chip were combined to produce a prototype NIR light source. This device generates a NIR output power of 44.43 mW and a photoelectric conversion efficiency of 10.4% when driven at 150 mA, demonstrating a good performance of this material for practical applications.
研究领域:
材料科学
·
光学
·
固体物理
✓ 已验证
DOI
Materials Chemistry Frontiers
·
2020
·Vol. 5
·期 2
·937-943
·
IF 6.788
Xupeng Gao,Xinyu Shen,Dingke Xue,Xin Li,Po Lu,Min Lu,Chunyan Li,William W. Yu,Xue Bai
Two-dimensional (2D) perovskites have become a research hotspot due to their large exciton binding energy and excellent stability. However, it is difficult to achieve longer wavelength emission than blue and green light in the 2D perovskites owing to their wide band gap resulting from their strong quantum confinement. Herein, we demonstrate a simple, efficient and low energy consumption crystallization method at room temperature to synthesize Mn2+ ion doped 2D (PEA)2PbBr4 nanocrystals (NCs) with dual-color emission centered at 410 nm from the exciton transition of the host and 600 nm from the d–d transition of Mn2+ ions. The periodic XRD peaks prove the formation of 2D perovskites. It is reassuring that the high PLQY of 54% has been achieved in the Mn2+ ion doped 2D (PEA)2PbBr4 NCs. The temperature-dependent and time-resolved spectra illustrate the efficient energy transfer from excitons to Mn2+ dopant ions. The realization of white LEDs with different color temperatures presents an opportunity and prospect for Mn2+ ion doped 2D perovskites in LED application.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Light-Science & Applications
·
2019
·Vol. 8
·期 1
·1-9
·
IF 14
Zhao Ming,Liao Hongxu,Molokeev Maxim S.,Zhou Yayun,Zhang Qinyuan,Liu Quanlin,Xia Zhiguo
Phosphor-converted white LEDs rely on combining a blue-emitting InGaN chip with yellow and red-emitting luminescent materials. The discovery of cyan-emitting (470–500 nm) phosphors is a challenge to compensate for the spectral gap and produce full-spectrum white light. Na 0.5 K 0.5 Li 3 SiO 4 :Eu 2+ (NKLSO:Eu 2+ ) phosphor was developed with impressive properties, providing cyan emission at 486 nm with a narrow full width at half maximum (FWHM) of only 20.7 nm, and good thermal stability with an integrated emission loss of only 7% at 150 °C. The ultra-narrow-band cyan emission results from the high-symmetry cation sites, leading to almost ideal cubic coordination for UCr 4 C 4 -type compounds. NKLSO:Eu 2+ phosphor allows the valley between the blue and yellow emission peaks in the white LED device to be filled, and the color-rendering index can be enhanced from 86 to 95.2, suggesting great applications in full-spectrum white LEDs.
研究领域:
材料科学
·
光学工程
·
固态照明技术
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 5
·1690-1697
·
IF 8.067
Mengmeng Cao,Chao Xia,Yunpeng Liu,Jinfeng Xia,Danyu Jiang,Guohong Zhou,Tongtong Xuan,Huili Li
Rapid and quantitative detection of nitrobenzene (NB) in wastewater is of great significance to protect the natural environment and human health. In this work, bifunctional Ln@Zr-MOFs based on UiO-66 were successfully fabricated by partially replacing terephthalic acid (H2BDC) ligands with m-phthalic acid (m-H2BDC) ligands and post-synthetic modification (PSM) with Ln3+ (Ln3+ = Eu3+, Tb3+). The “antenna effect” of the m-H2BDC ligands makes Ln@Zr-MOFs exhibit the characteristic emissions of Ln3+. By adjusting the amount and type of Ln3+, controllable color-tuning emissions can be easily realized, which endows them with a great application prospect for white LEDs. On the other hand, Eu10@Zr-MOFs can serve as a turn-off fluorescent switch of NB because the red emission from Eu3+ can be easily quenched by NB through a photoinduced electron transfer (PET) process between NB and its ligands, and as a result, NB is successfully recognized. Particularly, Eu10@Zr-MOFs as a fluorescent probe have shown many appealing properties, such as high sensitivity (limit of detection is 1.04 μM, limit of quantification is 3.48 μM, and Ksv = 24459.71 M−1), quick response (less than 60 s), a broad response window (0–180 μM), excellent selectivity, and strong anti-interference ability. The real detection results of NB concentration in natural water samples have demonstrated that the reported Eu10@Zr-MOFs are a potential fluorescent material that can precisely and sensitively perform fluorescence sensing of NB.
研究领域:
材料科学
·
环境科学
·
光学
✓ 已验证
DOI
高影响因子
Coatings
·
2021
·Vol. 11
·期 5
·581
·
IF 2.881
Linyuan Lian,Youyou Li,Daoli Zhang,Jianbing Zhang
InP quantum dots (QDs) are promising down-conversion phosphors for white light LEDs. However, the mainstream InP QDs synthesis uses expensive phosphorus source. Here, economic, in situ-generated PH3is used to synthesize InP QDs and a two-step coating of ZnS shells is developed to prepare highly luminescent InP/ZnS/ZnS QDs. The QDs show a photoluminescence quantum yield as high as 78.5%. The emission can be tuned by adjusting the halide precursor and yellow emissive InP/ZnS/ZnS QDs are prepared by judiciously controlling the synthetic conditions. The yellow QDs show suppressed thermal quenching and retain >90% room temperature PL intensity at 150 °C for the growth solution. Additionally, the PL spectrum matches with the eye sensitivity function, resulting in efficient InP QD white light LEDs.Keywords:InP;quantum dots;core/shell;InP/ZnS;thermal quenching
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
Nanoscale Advances
·
2020
·Vol. 2
·期 11
·5403-5411
·
IF 0
Weidong Han,Su-Hyeong Chae,Taewoo Kim,Daewoo Lee,Hakyong Kim
White-light-emitting materials have received significant attention because of their potential application in lighting, displays, and sensors. However, it is a challenge to obtain white light from one phosphor, because the basic requirement of the white light emission spectrum is that it should be wide enough to cover the entire visible light region. In this study, we have designed and demonstrated a white-light-emitting PMMA–CBS-127/PVP–coumarin 6/PAN–rhodamine B (PSCR) fibrous membrane, which was prepared through a triphasic electrospinning method. Three luminescent organic dyes, CBS-127 (4.77 wt%, blue), coumarin 6 (0.1 wt%, green), and rhodamine B (0.42 wt%, red), were elaborately selected and doped into PMMA, PVP, and PAN, respectively. The resulting flexible PSCR membranes show white light emission (cover the entire visible-light region from 382 to 700 nm) with Commission Internationale de L'Eclairage (CIE) coordinates of (0.31, 0.32), which is very close to ideal white light with CIE coordinates (0.33, 0.33). In addition, the PSCR membranes maintained high-quality white light emission after about 10 weeks of storage. The PSCR membranes can be used as the phosphor converting layer in white light-emitting diodes (WLEDs) through a remote membrane packaging method. A bright white emission is achieved at an applied voltage of 9 V. Therefore, the results indicate that PSCR membranes are potentially attractive candidates for application in WLEDs and displays.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Dan Zhao,Shi-Rui Zhang,Yan-Ping Fan,Bao-Zhong Liu,Ya-Nan Li,Lin-Ying Shi,Shao-Jie Dai
Developing broad-band-emitting phosphors is very important to light-emitting diode (LED) lighting and displays. We introduced Eu2+ to solid solutions K2YZr1–yHfy(PO4)3 with a langbeinite-type structure to prepare a series of new phosphors. In this structure, two K+ sites could be occupied by Eu2+ cations to provide two different kinds of coordination environments, leading to broad emitting bands in the range of 390–700 nm. The coordination circumstance of Eu2+ was analyzed by Gaussian fitting and time-resolved emission spectra. Furthermore, the emitting intensity and thermal stability can be improved by modulating the crystalline field via substituting Zr4+ by Hf4+. When the Zr4+ was fully substituted by Hf4+, the external quantum efficiency increased by 53.75%, giving a bright cyan emission. Finally, an archetype white-LED lamp was made using cyan phosphor K2YHf(PO4)3:0.04Eu, red phosphor CaAlSiN3:Eu2+, and a 365 nm LED chip, which realized an applicable color rendering index (Ra = 81) and a correlated color temperature (CCT = 3792 K).
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）