OPTICAL MATERIALS
·
2021
·
IF 3.08
Xiao Min,Mengzhu Hu,Yaoyao Yang,Bingfa Liu,Yuheng Wu,Yuansheng Wu,Lixin Yu
The effect of fluxes on CaSi 2 O 2 N 2 :Eu 2+ phosphors obtained via conventional solid-state reaction at atmospheric pressure is systematically investigated. The photoluminescence excitation and emission spectra of CaSi 2 O 2 N 2 :Eu 2+ phosphors containing fluxes are investigated and discussed in detail. A strong emission band is observed peaked at 548 nm originating from transitions between 4f 6 5d 1 emitting state and 4f 7 ground state of Eu 2+ under near ultraviolet light (398 nm) excitation. The results show that the best synthesis temperature of the sample is 1450 °C with the absence of combustion aid to obtain single phase of CaSi 2 O 2 N 2 :Eu 2+ . After adding BaF 2 , NH 4 Cl and Na 2 CO 3, single phase samples of CaSi 2 O 2 N 2 :Eu 2+ with well-defined morphology can be successfully prepared at a temperature as low as 1400 °C. It is interesting that in the samples prepared under the assistance of BaF 2 fluxes, the luminous intensity of Eu 2+ is much higher than in the absence of fluxes.
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 MATERIALS CHEMISTRY
·
2012
·Vol. 22
·期 31
·15887-15893
·
IF 5.968
Hongde Luo,Jie Liu,Xiao Zheng,Lixian Han,Kuaixia Ren,Xibin Yu
Trivalent ions B3+, Al3+ and Ga3+ have been introduced into Sr3SiO5:Ce3+ in this study. Among these ions, Al3+ and Ga3+ act as charge compensators and significantly enhance the maximum emission of Ce3+ by about 100% and 90%, respectively. Then, Al3+, Eu2+ co-doped Sr3SiO5:Ce3+ phosphors have been researched, which indicate that the emission spectra can be tuned from 530 to 575 nm by changing the concentration of Eu2+. The CIE chromaticity coordinates of the phosphors were calculated from (0.342, 0.518) to (0.442, 0.479). This indicates a potential for applications in daylight LEDs or warm-white LEDs.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 30
·期 17
·16384-16394
·
IF 2.195
Dong Chao,Zhang Yanjie,Duan Jianjun,Yu Jingjie
A series of Eu 2+ and Eu 3+ coexisting Ca 2 P 2 O 7 phosphors with tunable red/blue (R/B) emission have been successfully synthesized by a two-step method. Phase composition, luminescence properties and surface states are investigated by the X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL) emission spectra, fluorescence quantum efficiency, fluorescent lifetime and X-ray photoelectron spectroscopy (XPS). It can be concluded from XRD and FTIR results that pure Ca 2 P 2 O 7 phase can be obtained at 900 °C and Ca 3 (PO 4 ) 2 impurity phase occurs at an increasing preparation temperature (1100 °C). The XRD results confirm that the Eu 2+ or Eu 3+ doped samples all exhibit pure tetragonal Ca 2 P 2 O 7 crystal with space group P 4 1 . Under excitation of 330 nm, Eu 2+ singly-doped Ca 2 P 2 O 7 phosphors showed a broad blue emission band at 422 nm, while the Eu 3+ single-doped samples emitted a strong orange-red light with wavelength of 591, 597 and 618 nm excited by 395 nm. In particular, oxygen vacancies in pure Ca 2 P 2 O 7 crystal are found due to the strong PL emission at 420 nm. Furthermore, Eu 2+ /Eu 3+ co-doped Ca 2 P 2 O 7 phosphors prepared by this two-step synthesis show the blue emission at 422 nm (Eu 2+ ions) and the orange-red emission (Eu 2+ ions) at 591 nm, 597 nm and 618 nm under near-ultraviolet (NUV) excitation of 380 nm. It was detected that the quantum efficiency of the Ca 1.88 P 2 O 7 :0.12Eu phosphor was 37.7%. The tunable R/B emission ratio from 0.13 to 1.56 can be achieved by controlling the recalcined temperature in the second step when excited by 380 nm. The XPS demonstrate the existence of Eu 3+ ions on the surface of Eu 2+ /Eu 3+ co-doped Ca 2 P 2 O 7 phosphors. Under NUV excitation in the range from 350 to 400 nm, the optimum Commission International de I’Eclairage (CIE) coordinate of Ca 2 P 2 O 7 :0.12Eu 2+ /Eu 3+ phosphors is (0.3648, 0.215), which can be potentially used as an emitting source to meet the needs of illumination devices.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2024
·
IF 5.7
Mingjun Zhao,Panting Wang,Chongyun Shao,Weichang Li,Danping Chen,Wei Chen
Novel transparent luminescent glass ceramics with the ability to generate the line emission of Eu2+ ions were successfully prepared. First, Eu2+-doped barium–aluminum–borate oxyfluoride glasses were prepared by high-temperature melting in a reducing atmosphere, and then transparent glass ceramics were obtained by crystallization heat treatment. Fluorescence spectroscopy showed that Eu2+ exhibited only broadband luminescence (FWHM ≈ 136 nm) of the 4f65d1 → 4f7 transition in the glasses. However, after heat treatment, a 359 nm line emission (FWHM ≈ 2.8 nm) from the 4f7 → 4f7 transition of Eu2+ appeared in the glass ceramics. To explore the mechanism of transformation of the optical transition of Eu2+ from 4f65d1 → 4f7 to 4f7 → 4f7, the glasses and glass ceramics were analyzed by fluorescence spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, and electron paramagnetic resonance (EPR) spectroscopy measurements. The results showed that the alteration in the optical transition of Eu2+ was a result of the Eu2+ ions entering the Ba2+ sites with weak crystal field strength in BaAlBO3F2 (BABF) crystals from the strong crystal field strength glass phase.
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
Xiaoshuai Zhang,Wen Xiong,Chengrun Liu,Zixuan Wang,Xiaoyan Yu,Xiaojie Li,Guodong Zhang,Panlai Li,Zhijun Wang
Exploring oxide-based deep red light-emitting phosphors is crucial for indoor plant lighting applications. In particular, designing Eu 2+ deep red emission in inorganic solids is challenging. In this paper, a cation substitution strategy was used to replace the Ca 2+ ions in the matrix with a certain concentration of Sr 2+ ions. A series of spectrally red-shifted Ca 1-x Sr x Sc 2 O 4 :Eu 2+ deep red phosphors were obtained under 460 nm light excitation. The substitution of Sr 2+ ions changes the local crystal field environment of Eu 2+ . The spectral shift from 656 nm to 702 nm was achieved by changing the centroid shift, the degree of polyhedral distortion and the lattice disorder. Combined with the need for practical applications, Ca 0.5 Sr 0.5 Sc 2 O 4 :0.01Eu 2+ phosphor and blue chip have been made into phosphor-converted light-emitting diodes for plant lighting, and the results of plant lighting experiments show that Ca 0.5 Sr 0.5 Sc 2 O 4 :0.01Eu 2+ phosphor has a certain application potential in plant lighting. In addition, this study will guide the exploration of new oxide-based deep red phosphors with Eu 2+ activation and for the realization of tunable emission through cation substitution.
研究领域:
材料科学
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光学工程
·
植物学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Chenxia Li,Bowen Chen,Degang Deng,Hua Yu,Hao Li,Changyu Shen,Le Wang,Shiqing Xu
The La 1-0.03- y Gd y AlO 3 : 0.03Eu ( y = 0.2–0.8) phosphors are prepared via solid phase method. The normal thermal quenching of Eu 2+ ion and abnormal thermal quenching of Eu 3+ ion in La 1-0.03- y Gd y AlO 3 : 0.03Eu ( y = 0.2–0.8) phosphors are explained by the configuration coordinate system and energy transfer process . Considering the fluorescence intensity ratio temperature measurement technology, the temperature sensitivity values of the phosphors increase with the increase of Gd 3+ ion concentration . When Gd 3+ ion concentration is 0.8, the maximal S a and S r can even reach 0.084 K -1 and 3.233% K −1 . Moreover, the excellent separation of emission peaks of Eu 2+ and Eu 3+ ions also provides good signal discriminability for temperature measurement. These results indicate that the La 1-0.03- y Gd y AlO 3 : 0.03Eu phosphors can be used as the superior non-contact optical thermometry materials.
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 RARE EARTHS
·
2025
·
IF 7.2
Dilare Halmurat,Xinyu Zhang,Litipu Aihaiti,Rong-Jun Xie
Eu 2+ -doped phosphors show broadband absorption, tunable emission and high quantum efficiency due to the parity-allowed 5d→4f transitions, allowing them to be used in solid-state lighting. To expand their applications in other fields such as detection and sensing technologies, the Eu 2+ emission needs to be tuned into the near-infrared region, but it is a big challenge to obtain Eu 2+ near-infrared region emitters due to the absence of host compounds with extremely large crystal-field splitting. In this work, we chose M 4 Li(BN 2 ) 3 (M = Ca, Sr, Ba) as a host and realize the near-infrared region emission of Eu 2+ in it. Among these phosphors, Ba 4 Li(BN 2 ) 3 :Eu 2+ exhibits the longest emission of 880 nm and the largest full-width at half maximum of 276 nm under 450 nm excitation, while Ca 4 Li(BN 2 ) 3 :Eu 2+ and Sr 4 Li(BN 2 ) 3 :Eu 2+ emit at 740 and 680 nm, respectively. We observe an interesting phenomenon that the energy shift of emission is linearly related to the radius difference between the alkaline earth cation and the activator Eu 2+ in this system.
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 LUMINESCENCE
·
2021
·
IF 3.599
Yanzhen Yin,Maochen Zhu,Yue Zhang,Chen Hu,Zhen Wang,Yang Che,Jingyao Lu,Ruyi Sun,Jiaqi Zhao,Bing Teng,Jianhong Li,Shijia Sun,Degao Zhong
High quantum efficiency and thermal stability have always been the goals to pursue and challenges for lighting application. In this work, sunlight-like white emission has been achieved in a new prepared single phased Rb 2 CaP 2 O 7 : 0.005Ce 3+ , 0.01Eu 2+ phosphor, which exhibits high internal quantum efficiency (IQE = 74.36%), external (EQE = 56.77%) quantum efficiency and excellent thermal stability. Based on the broadband emission from 4f-5d transitions of Ce 3+ /Eu 2+ ions and high energy transfer efficiency of Ce 3+ →Eu 2+ (measured up to 60%), the extremely wide color-tunable emission from blue-violet to white and then to orange-yellow is realized in Rb 2 CaP 2 O 7 : 0.005Ce 3+ , xEu 2+ phosphors. Moreover, a prototype WLED device is packaged by combing the prepared Ra 2 CaP 2 O 7 : 0.005Ce 3+ , 0.01Eu 2+ white phosphors with an UV LED chip (λ = 310 nm), and the obtained WLED emits bright sunlight-like white light with color coordinates of (0.377, 0.324). The correlated color temperature (CCT) and the color rendering index (CRI) value of the WLED are 3208 K and 88.4, respectively. These results can provide effective guidance for the design of color-tunable single-phase white phosphors with high luminous efficacy and thermal stability.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Yue Yang,Rong Tang,Yuqi Lei,Di Gao,Houteng Zhao,Samra Jabeen,Yufeng Du,Ya Yang,Chenyi Wang,Xinyue Zhang,Ruijin Yu,Xianchao Du
To realize full-spectrum illumination systems for daily applications, the development of cyan-emitting phosphors capable of addressing the spectral deficiency in the 480-520 nm region (between blue and green emissions) has emerged as a critical research frontier in solid-state lighting technology. In this investigation, a scandium silicate phosphor, KSr 6 ScSi 4 O 16 :Eu 2+ , was initially synthesized via a high-temperature solid-state reaction under a reducing atmosphere. The target compounds crystallize in an orthorhombic system with a centrosymmetric space group of Pnma (No. 62). KSr 6 ScSi 4 O 16 :2 mol%Eu 2+ shows asymmetric broadband mainly at 481 nm under excitation of 359 nm. Based on Gaussian fitting and Van Uitert's equation, the Eu 2+ ion was confirmed to occupy two different coordination environments of Sr 2+ , producing two different luminescent centers at 477 nm and 528 nm. The optimal doping concentration of KSr 6 ScSi 4 O 16 : x Eu 2+ cyan phosphors was founded to be 2 mol%. Within the temperature range of 300 to 480 K, CIE coordinates remain stable during the heating process, and an activation energy of 0.35 eV has been determined. The color rendering index ( R a ) of the full spectrum WLED produced by KSr 6 ScSi 4 O 16 :Eu 2+ , reached 92.5, which is higher than the WLED packaged with commercial powder, effectively supplementing the cyan light component and closer to the full-spectrum lighting LEDs.
研究领域:
材料科学
·
固态照明技术
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Lang Pei,Yingqiang Yu,Zhanfeng Ma,Xusheng Wang,Qinan Mao,Jiasong Zhong
Sr2MgSi2O7/Eu2+, Dy3+ (SMSED) phosphors show promise for persistent luminescence applications due to their long afterglow and robust chemical stability. However, a trade-off exists between achieving precise size and shape control of SMSED and maintaining prolonged afterglow intensity and duration during synthesis. Herein, we unveil a molten-salt method that successfully produces uniform single-crystalline plate-like SMSED for the first time. This synthesis significantly reduces both the sintering temperature and time compared to the classic solid–state reaction (SSR) method. Owing to the nanoplates structure, uniform size distribution, and single-crystal nature, the resulting SMSED exhibited excellent afterglow performance and thermal stability, with a sustained blue afterglow exceeding 24 h and retaining >70% of its initial luminescence up to 523 K, outperforming most reported SMSED phosphors. These remarkable properties underscore the considerable potential of SMSED nanoplates for applications in fingerprint detection. This work unlocks a new synthetic frontier for achieving the controllable synthesis of SMSED phosphors, paving the way for future optimizations aimed at the development of advanced persistent luminescent phosphors.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
·
2023
·
IF 3.6
Jiawen Li,Jiawen Wang,Feifei Huang,Youjie Hua,Shiqing Xu,Ruoshan Lei
In pursuit of healthy lighting, the exploitation of high-quality Eu 2+ -activated phosphors available for near-ultraviolet light-emitting diode (NUV-LED) chip-based white LED (WLED) has fetched growing interest. Herein, a novel NUV-light excitable Rb 3 GdSi 2 O 7 : Eu 2+ phosphor is successfully synthesized via a high-temperature solid-state reaction method. The crystal structure of Rb 3 GdSi 2 O 7 is found to be hexagonal, belonging to space group P6 3 /mmc. The Rb 3 GdSi 2 O 7 : Eu 2+ phosphor exhibits a broad excitation band in the 300–450 nm wavelength range, and it emits strong yellow-green light with peak at 543 nm upon 365 nm excitation. Benefitting from the high structure rigidity of host matrix, Rb 3 GdSi 2 O 7 : Eu 2+ also possesses a desired luminescence thermal stability (423 K, 85.6%). The WLED device fabricated using a 365 nm chip and a blend of the as-prepared Rb 3 GdSi 2 O 7 : Eu 2+ yellow-green phosphor and commercial BaMgAl 10 O 17 : Eu 2+ blue phosphor displays an excellent color-rendering index of 95.9 at a low correlated color temperature of 4373 K. This work confirms the applicative potential of Rb 3 GdSi 2 O 7 : Eu 2+ in NUV-converted warm WLEDs, which may promote the development of high-color-quality healthy 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
OPTICAL MATERIALS
·
2020
·
IF 2.779
Shichang Xu,Jianjun Duan,Peipei Dong,Muyao Wang,Yanjie Zhang,Jingjie Yu
A series of Eu 2+ activated Ca 10 (PO 4 ) 6 Cl 2 phosphors (ClAp: Eu 2+ ) with enhanced blue emission have been prepared by the deposition precipitation (DP) process. The XRD patterns indicate that Eu 2+ ions are incorporated into Ca 10 (PO 4 ) 6 Cl 2 lattice during the DP process. The ClAp: xEu 2+ -DP phosphor exhibits an super broad excitation band of 250 nm–420 nm consisting of three distinct peaks at 276 nm, 343 nm and 365 nm, ascribed to the 4f 6 → 4f 7 5 d 1 transition of Eu 2+ ions in 4f and 6 h sites. Under 350 nm excitation, ClAp: xEu 2+ -DP phosphors show the intense blue emission at 453 nm and the maximum intensity is obtained when x = 0.3. Notably, an enhanced blue emission intensity of ~2.1 times can be found for ClAp:0.3Eu 2+ -DP phosphor compared with the sample prepared by traditional solid state reaction (SSR) method. Further, the EDX elemental mapping of the phosphor demonstrates that DP process can effectively promote the uniform distribution of Eu 2+ ions on the surface of ClAp crystal and avoid the aggregating problem of activators in SSR method, which can greatly improves the photoluminescence property. It can be concluded from HRTEM images and decay curves that ClAp:0.3Eu 2+ -DP phosphor exhibits characteristic lattice fringes similar to those of ClAp:0.3Eu 2+ -SSR phosphor, but a longer average decay lifetime (392 ns). In addition, the presence of trivalent europium ions on the surface of ClAp: 0.3Eu 2+ -SSR and ClAp: 0.3Eu 2+ -DP phosphors can be identified by XPS analysis . All the results reveal that DP process is an efficient way to prepare highly dispersed Eu 2+ activators in Ca 10 (PO 4 ) 6 Cl 2 host and the ClAp: Eu 2+ -DP phosphors can be the promising candidate for blue emission in white LEDs.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
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