JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Shuai Wei,Zhijun Li,Zeyu Lyu,Dashuai Sun,Sida Shen,Jianhui Wang,Chengyu Zhuo,Hongpeng You
In this work, we provide a paradigm how to realize white light emission by utilizing the energy transfer from the Bi 3+ to Eu 3+ ions. First, a novel Bi 3+ activated phosphor set of highly oxygen-deficient perovskite derivatives (Ba 3 YGa 2 O 7.5 , BYGO) were synthesized through the conventional high-temperature solid-state method. The crystal structure was confirmed by Rietveld refinement . Then, Eu 3+ was introduced to the phosphor composition to construct energy transfer pathway with Bi 3+ . The emission color of the BYGO:Bi 3+ ,Eu 3+ phosphors can be changed from cyan to white and orange-red by altering the Bi 3+ /Eu 3+ doping ratio. The energy transfer from the Bi 3+ to Eu 3+ ions was ascribed to dipole-dipole interaction. Finally, a single-component WLED device with a color-rendering index of 84.9 was successfully prepared by employing a near-ultraviolet chip and the BYGO:Bi 3+ ,Eu 3+ phosphors. This work not only indicates that the as-prepared BYGO:Bi 3+ ,Eu 3+ phosphors are a potential candidate for near-ultraviolet WLED, but also demonstrated that energy transfer is an avenue for single-phased white light emission.
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 SOLID STATE CHEMISTRY
·
2021
·
IF 3.498
Han Zhang,Guan-Yu Ding,Afifa Yousaf,Li Chen,Xin-Long Wang,Guo-Gang Shan,Chun-Yi Sun,Zhong-Min Su
Luminescent sensors have received extensive attention due to their fast-response and easy-operation and when integrating multifunctions in a sensor, the cost will be reduced substantially. Covalent organic polymers (COPs) as multifunctional luminescent sensor with outstanding performance are still underexplored. In this work, a typical COP named as COP-2 show preponderant performance in the detection of Fe 3+ , MnO 4 − , and TNP. COP-2 has the highly efficient ability to selectively detect Fe 3+ among the other metal ions , and the limit of the detection (LOD) is 0.89 μ M, which outperforms the reported covalent organic materials. Anion sensing shows the COP-2 has the highly anti-interference ability and recyclicity to detect MnO 4 − . Explosive analogs sensing demonstrates that COP-2 owns the superior ability in sensing TNP in the knockdown concentration with 0.0067 ppm LOD, which superior to the values in the reported literature. In addition to the above superb sensing performance, COP-2 can be utilized as a white light-emitting diode (WLED) when combined with the commercial blue emission LED and presents a Commission Internationale de l’Eclairage (CIE) coordinate of (0.31, 0.32). These results show the COP-2 not only has an appealing performance in multifunctional luminescent sensing application, but also has a possible application in white light emitting.
研究领域:
材料科学
·
化学传感
·
光学器件
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Qinghai Sun,Zhibo Zheng,Xiaolu Yang,Yanxia Zhao,Zhou Luo,Chao Wang,Yanhua Song,Haifeng Zou,Shihou Sheng
Herein, a variety of single-phase full-spectrum emission phosphors doped with Eu 2+ were synthesized. Under the 350 nm excitation, as K + and Y 3+ were introduced into Ca 10 Na(PO 4 ) 7 (CNP):1.5%Eu 2+ , respectively, the emission color of Ca 9.85 K y Na (1- y ) ( PO 4 ) 7 :1.5%Eu 2+ (0 ≤ y ≤ 1.0) was tuned from yellow to cyan, while that of Ca (9.85- z ) NaY 0.667 z (PO 4 ) 7 :1.5%Eu 2+ (0 ≤ z ≤ 1.0) was tuned from yellow to green. The internal quantum yield (QY) of Ca 9·85 K 0·4 Na 0·6 (PO 4 ) 7 (CKNP):1.5%Eu 2+ and Ca 9·45 NaY 0·267 (PO 4 ) 7 (CNYP):1.5%Eu 2+ reached 47.47 % and 27.11 %, respectively. The introduction of K + or Y 3+ made Eu 2+ selectively occupy the Ca sites and led to changes in the local environment of Eu 2+ , allowing for spectral tuning emission. In addition, the luminescence intensity of the samples retained 54.59 % and 31.34 % of their room temperature values. Eventually, two white light emitting diode (WLED) devices were fabricated, combining the synthesized white emitting phosphors with 365 nm ultraviolet (UV) chips. They exhibited high color rendering indices of 84.7 and 77.0, along with low correlated color temperatures of 5435 K and 5023 K. The Commission Internationale de L'Eclairage (CIE) color coordinates were (0.3349, 0.3975) and (0.3517, 0.4366), respectively. The results pointed to the phosphors' potential suitability for use in the WLED sector.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2021
·Vol. 9
·期 19
·2100337
·
IF 9.926
Dan Zhang,Xiangting Zhang,Baofeng Zheng,Qi Sun,Zhibo Zheng,Zhan Shi,Yanhua Song,Haifeng Zou
A series of Eu 2+ single doped Ca 9 Na 1– x Li x Sc 0.667 (PO 4 ) 7 phosphors with full-spectrum emission have been synthesized. Under the 385 nm excitation, the Eu 2+ single doped Ca 9 NaSc 0.667 (PO 4 ) 7 without Li + doping displays a broad cold white light emission with the peaks at about 480 and 610 nm. With the introduction of Li + ions, the Eu 2+ ions selectively occupy the Ca1, Ca2/Ca3, and Na sites. The variation of local environment of Eu 2+ ions caused by Li + ions enhances the luminous intensity, solves the problem of the lack of a red light component, and realizes the emission color tuning from cold white via warm white to orange. A special charge compensation method caused by Li + migration avoids the generation of defects and is beneficial to the improvement of luminescence properties. Eventually, a warm white light-emitting diode device is prepared by combining the white emitting Ca 9 Na 0.8 Li 0.2 Sc 0.667 (PO 4 ) 7 :2%Eu 2+ phosphors with 385 nm LED chip, which exhibits a high color-rendering of 92.9, low correlated color temperatures of 4529 K, and excellent color stability under working temperature. The as-reported warm white emitting Eu 2+ -doped phosphors have potential applications in full-spectrum solid-state lighting. The site engineering strategy provides an extensive guide for optimizing and designing novel single-composition white-emitting phosphor materials.
研究领域:
材料科学
·
光学工程
·
固态照明
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Yali Xue,Yujun Liang,Yi Dou,Haoran Li,Qiangke Wang,Xiaodeng Wu,Yongsheng Han
Reabsorption and color drift at high temperature hinder the high-quality application of the phosphor-converted white light-emitting diodes (pc-WLEDs) devices, thus it is urgent to develop the single-phase white-emitting phosphors with good chromatic stability. In this work, a series of color-tunable Y 3 TaO 7 :Bi 3+ , Eu 3+ phosphors are designed by co-doping Bi 3+ and Eu 3+ based on the crystal structure information and energy transfer principle between Bi 3+ and Eu 3+ , which can be adjusted to achieve single-phase white emission. By increasing the temperature to a high value of 473 K, the emission peak of Bi 3+ ions still present at 470 nm in Y 3 TaO 7 :Bi 3+ phosphors even when the concentration of Bi 3+ ions changes, and the characteristic emission peaks of Bi 3+ and Eu 3+ basically maintain unchanged throughout in Y 3 TaO 7 :Bi 3+ , Eu 3+ phosphors. Finally, the single-phased Y 3 TaO 7 :0.025Bi 3+ , 0.06Eu 3+ phosphor was employed with ultraviolet chip to produce a warm WLED device with color rendering index of 81.5, correlated color temperature of 4165 K and the Commission International de I′Eclairage chromaticity coordinates of (0.3645, 0.3347). The results indicate that Y 3 TaO 7 :Bi 3+ , Eu 3+ phosphors with high chromaticity stability have great application potential in full-spectrum 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
NANOTECHNOLOGY
·
2018
·Vol. 29
·期 28
·285706
·
IF 3.404
He Shao,Xue Bai,Gencai Pan,Haining Cui,Jinyang Zhu,Yue Zhai,Jingshi Liu,Biao Dong,Lin Xu,Hongwei Song
Inorganic perovskite quantum dots (QDs) have attracted wide attention in display and solid-state lighting because of their easily tunable band-gaps and high photoluminescence quantum yields (PLQY) of green light emission. However, some drawbacks limit their practical applications, including the low PLQY of blue light emission and the instability in the moisture environment. In this work, efficient blue-light emitting CsPbBr3 perovskite QDs with PLQY of 72% were developed through a bandgap engineering approach. The achieved blue-light emitting PLQY is much higher than the values acquired in the inorganic perovskite QDs in the literature. And the emission color of the as-prepared QDs can be facially tuned by only adjusting the reaction temperature. Further, the mono-dispersed perovskite QDs@SiO2 composites were constructed benefiting from the low temperature synthesis. The optical performance of the QDs could be well persisted even in the moisture environment. Finally, the as-prepared QDs@SiO2 composite was fabricated as the QD ink on the anti-counterfeit printing technology, from which the obtained pattern would emit varied color under UV lamp. And the as-prepared composites was also applied for fabricating WLED, with Commission Internationale de l'Eclairage (CIE) color coordinates of (0.33, 0.38) and power efficiency of 32.5 lm W−1, demonstrating their promising potentials in solid-state lighting.
研究领域:
材料科学
·
纳米技术
·
光电
·
固态照明
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2023
·
IF 3.3
Yingguang Li,Mingwei Fu,Peng Qiao,Shulian Liu,Degang Deng,Shiqing Xu,Hongping Ma
In this study, a non-activated ion-doped full-spectrum emission phosphor for white light-emitting diode (WLED) lighting is proposed using oxygen defect engineering. The YMZn 3 AlO 7 (M = Ca, Sr, Ba) phosphors with "114″ structure were prepared via a high-temperature solid-state reaction. Under excitation with 373 nm ultraviolet (UV) light, YSrZn 3 AlO 7 in YMZn 3 AlO 7 (M = Ca, Sr, Ba) exhibited the highest emission intensity and formed a wide yellow emission band centred at 563 nm. The full width at half maximum of the YSrZn 3 AlO 7 phosphor was 172.6 nm. A theoretical model based on the designed oxygen vacancies was proposed to determine the self-activated luminescence mechanism. Density functional theory calculations revealed that oxygen vacancies lead to the generation of new energy levels. Electron paramagnetic resonance experiments further confirmed that the luminescence originated from oxygen vacancies. Eventually, a warm WLED device ((x, y) = (0.4057, 0.4359)) with a correlated color temperature of 3814 K and a relative color rendering index of 83 was successfully prepared using the YSrZn 3 AlO 7 phosphor and a 365 nm UV LED chip. These results suggest that YSrZn 3 AlO 7 is a promising WLED phosphor and provide new insights into the application of self-activated phosphors in WLED.
研究领域:
材料科学
·
光电技术
·
照明技术
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2024
·
IF 3.8
Sihan Yang,Xuyan Xue,Ziying Wang,Qi Zhu,Xuejiao Wang,Ji-Guang Li
In this work, a series of broad-band green phosphors SrLaScO 4 : x Bi 3+ ( x = 0–0.1) were synthesized using the traditional solid-state method, and the luminescence was effectively enhanced via multi cationic partial substitution strategy. The SrLaScO 4 : x Bi 3+ phosphors all exhibit a wide emission band with a full width at half-maximum (FWHM) of 115–148 nm in the range of 450–700 nm upon excitation at 333 nm, effectively filling the cyan gap and peaking at 505 nm. It is proved that the observed luminescence originates from both the 3 P 1 state of Bi 3+ in [(Sr/La)O 8 ] site and the Bi 3+ - to - Sc 3+ metal to metal charge transfer (MMCT) state. The optimal concentration of Bi 3+ doped SrLaScO 4 phosphor is 1 at%, and the concentration quenching mechanism is the dipole-dipole interaction. Remarkably, the luminescence intensity of the phosphor is 198.4 % increased by partially replacing Sr 2+ ions with Mg 2+ . Due to the good matching of the excitation wavelength of the phosphor with the near-UV chip, a high-quality WLED device with color stability and high color rendering index ( Ra = 92.1) was prepared by combining commercial phosphor with SrLaScO 4 :0.01Bi 3+ phosphor. We anticipate that this work can provide new ideas for finding high-performance phosphors for high color rendering index pc-WLED.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Tianyi Zhang,Feifei Zhao,Li Li,Bin Qi,Dongxia Zhu,Jianhua Lü,Changli Lü
The past few years have witnessed the rapid development of carbon dots (CDs) due to their outstanding optical properties and a wide range of applications. However, the design and control of CDs with long-wavelength multicolor emission are still huge challenges to be addressed for their practical use in different fields. Here, novel nitrogen-doped multiple-core@shell-structured AC-CDs with tricolor emissions of red, green, and blue were constructed via one-pot hydrothermal method from 5-amino-1,10-phenanthroline and citric acid as reactants and the growth process of AC-CDs was monitored with the reaction time in the synthetic system. The origin of different fluorescence emissions was explored using the unique coordination ability of the surface groups of AC-CDs. An obvious concentration dependence of fluorescent properties was observed for the as-prepared AC-CDs, and a highly fluorescent quantum yield (QY) of 67% for red emission at 630 nm can be obtained by adjusting concentration of AC-CDs. The pure white-light emission (0.33, 0.33; Commission Internationale de l’Elcairage coordinate) was carried out from single carbon dot with QY of 29% through regulation of the excitation and concentration of multiple-core@shell-structured AC-CDs. In addition, because of their excellent photoluminescent properties, the white-emitting AC-CDs as emitting phosphor can be easily used in the fabrication of white-light-emitting diode with good anti-photobleaching and temperature stability.
研究领域:
材料科学
·
光电技术
·
纳米技术
·
光子学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
OPTICAL MATERIALS
·
2021
·
IF 3.08
Weijie Ren,Jingjing Bai,Tingting Cai,Shijia Li,Ernan Pang,Hua Zhang,Zhenzhong Li
The heteroatom doping to achieve carbon dots has played a crucial part in exploring the fluorescence mechanism of multicolor emissions, which is closely related with the application development of such materials. Herein, a facile method was developed to synthesize three-color CDs via the co-doping of S and N elements with the assistance of ethanol solvent. The achieved CDs mainly emit blue, green and red lights, yet the photoluminescence quantum yields (FLQYs) generally decreases from 54.0% for B-CDs, 11.5% for G-CDs to 8.5% for R-CDs, respectively. Optical and structural characterizations of these CDs show that the variation of sp 2 - sp 3 hybridized domains resulted from the elements doping (S, N) fundamentally determines the color of CDs. The highest FLQYs of B-CDs in all CDs gives it an advantage to detect metal ions , which finds strong quenching only toward Ag + because of the interaction between Ag + and the cores. Likewise, these multicolor CDs attempt to fabricate CDs@PVP composite film emitted white-light as well as a clad material of WLED devices. The results indicate that the correlated color temperatures (CCT) in the ranges of cold and warm white lights can be obtained with different color rendering indexes (CRI) and luminous efficacies. Moreover, CCT and CRI are nearly up to the extremum at the same current value with increasing currents, implying that such CDs are potential as a kind of fluorescent nanomaterial to applicate to WLED device.
研究领域:
材料科学
·
纳米技术
·
光电技术
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Sai Lin,Mengyuan Chen,Ziwei Wang,Yijun Zhang,Rongrong Yuan,Xiaojuan Liang,Weidong Xiang,Yongqiang Zhou
Multicolor luminescent carbon dots (Cdots) are of immense importance nowadays, while it still a challenge to construction of full-color light-emitting Cdots and their efficient solid-state materials. Here in, we fabricated a facile method to synthesize multicolor Cdots by adjustment of the reaction temperature. Although all samples showed uniform distribution of particles size and similar graphite structure, the surface chemical composition gradually varied among Cdots, especially the oxygen contents and nitrogen contents. Detailed material characterization has revealed that this tunable emission is results from the changes of the chemical composition. It is believed that the surface oxidation become more severe at high temperature, resulting in the formation of higher oxygen and nitrogen, which are responsible for the long-wavelength emission. Meanwhile, flexible solid-state materials were successfully created by combination of organosilane (OSi) and Cdots, which can be used to prevent the aggregation-induced solid-state fluorescence quenching. Finally, red Cdots/OSi was stacked on the Y 3 Al 5 O 12 :Ce 3+ (Ce 3+ : YAG) phosphor-in-glass (Ce-PiG) via tape-casting technology. Then, warm white light-emitting diodes (WLEDs) were constructed by these materials and GaN chips. As the Cdots increases, the correlated color temperature (CCT) decreases while the color rendering index (CRI) increases, and the color coordinates shift towards the red region. The resulting color converting material produced a warm white by adjusting red Cdots content, which will be a promising candidate for applications in the warm WLED.
研究领域:
材料科学
·
光电技术
·
纳米技术
·
照明工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Xiao-Fei Wang,Gui-Gen Wang,Jia-Bing Li,Zheng Liu,Wen-Feng Zhao,Jie-Cai Han
In this article, a new application of using S, N co-doped graphene quantum dots (S, N-GQDs) as ideal color converters in solid-state white light-emitting diode (WLED) is reported. To this end, the S, N-GQDs with an average diameter of ∼4.46 nm are obtained by a hydrothermal approach using citric acid and thiourea as source materials. The PL spectra of S, N-GQDs show an excitation-independent behavior in the range of 300–380 nm. Under UV illumination, the S, N-GQDs display intense blue-light with the quantum yield of 51.2%. The PL mechanism is also investigated. Then, we fabricate freestanding luminescent composite films in a solution casting method by combining S, N-GQDs with YAG:Ce 3+ phosphors based on a polyvinyl alcohol (PVA) matrix. The luminescent films have superior foldability and photostability and excellent heat resistance, and retain their optical performances in the solid-state. To realize their potential, a high-powered remote WLED has been demonstrated. The results indicate that S, N-GQDs and YAG:Ce 3+ can be homogeneously dispersed in the PVA without aggregation so that uniform white-light emission can be obtained. These composite films containing S, N-GQDs are promising to be used in state-of-the-art UV-pumped remote WLED according to their wide wavelength emission and collapsible illumination device.
研究领域:
材料科学
·
光电技术
·
纳米技术
·
光子学
✓ 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）