JOURNAL OF LUMINESCENCE
·
2024
·
IF 3.3
Yaping You,Ya Zheng,Zesheng Pan,Yunluo Wang,Tianrui Zhou,Minghui Wang,Haijie Chen,Wan Jiang,Lianjun Wang
White light-emitting diode (WLED) has been widely used as solid-state lighting in recent years, with the advantages of energy saving, high luminous efficiency , and safety. Red phosphors are crucial to the color rendering index of WLED, and Eu 3+ -activated red phosphors can significantly improve the chromaticity performance of WLED. In this work, a series of new orange-red emitting BaLiZn 3 (PO 4 ) 3 : Eu 3+ phosphors were synthesized through high-temperature solid-state reaction method. The phase composition , crystal structure, morphology and photoluminescence properties of BaLiZn 3 (PO 4 ) 3 : Eu 3+ samples were investigated. The phosphors can be effectively excited by the violet light at 394 nm and emit orange-red lights corresponding to the electric dipole transition (5D 0 →7F 1 ) at 594 nm. The optimal doping concentration of Eu 3+ ions was about 5 mol%. The concentration quenching was caused by the electric dipole-dipole interaction between Eu 3+ ions. Temperature-dependent PL spectra indicate that BaLiZn 3 (PO 4 ) 3 : Eu 3+ has excellent emission and color stability at high temperatures. The color coordinates were calculated and fall in the orange-red luminescent area. The color purity is about 98.3 %, and the correlated color temperature is 1710K. These results indicate that the new orange-red phosphor BaLiZn 3 (PO 4 ) 3 : Eu 3+ has potential application prospects in WLED.
研究领域:
材料科学
·
发光材料
·
固体照明
·
无机化学
·
光电子学
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Zhiqin Zheng,Peizhang Xie,Panpan Yi,Jun Zhao,Lihong Liu,Facheng Yi
Nowadays, ultraviolet (UV) and blue converted phosphors have played a key role in the solid-state lighting field, and the white light is usually produced by mixing multiple phosphors. In this work, we report a type of UV converted single white phosphor, i.e. , Ba 9 La 2 Si 6 O 24 :Eu 3+ ,Bi 3+ .Various techniques, such as powder X-ray diffraction (XRD), scanning electron microscopic (SEM), photoluminescence (PL) spectra, and quantum efficiency (QE), have been used to characterize the samples. In Bi 3+ doped samples, upon excitation within the wavelength range of 250–380 nm can lead to three Bi 3+ emission bands ( i.e. , 358 nm, 415 nm, and 516 nm), but only one emission band peaking at 415 nm appears when the excitation wavelength exceeds 380 nm. Structural analysis and discussion on the PL intensity variation reveal there are three Bi 3+ luminescent centers at two different La 3+ sites and one Ba 2+ site. The Bi 3+ concentration-induced luminescent quenching is dominated by the d-d interaction. In view of the spectral overlap between the Bi 3+ emissions and the Eu 3+ excitation spectra , the energy transfer from Bi 3+ to Eu 3+ of the Ba 9 La 2 Si 6 O 24 :Eu 3+ ,Bi 3+ is studied, and it is dominated by a dipole-quadrupole ( d - q ) interaction. Moreover, upon excitation at 365 nm, the emissions broadly tuning from blue, white and to red are achieved by varying the Eu 3+ content. For the white Ba 9 La 2 Si 6 O 24 :Eu 3+ ,Bi 3+ sample, high temperature PL results show that it does not have severe degradation of emission intensity after increasing the temperature from 25 to 300 °C, exhibiting a good thermal stability . To show the potential application in the lighting fields, we fabricate a white light LEDs device by depositing this white phosphor on a 365 nm UV LED chip. As a result, the values, i.e. , a color rendering index (CRI) of 95, luminous efficiency of 80 lm/W, and color temperature (CT) of ~4215 K at chromaticity (0.382, 0.398), are achieved.
研究领域:
材料科学
·
发光材料
·
固态照明
·
无机化学
·
光电子学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2023
·
IF 5.2
Yuchi Guo,Zongxue Yu,Haidong Chen,Bokai Peng,Junlei Tang
This study aimed to design a composite epoxy coating HZB/EP with pH-responsive behavior by grafting different material functions. In this approach, ZIF-8 particles were self-assembled on the surface of hydroxyapatite (HAp) through in situ growth, followed by encapsulation of the corrosion inhibitor BTA. Scanning electron microscopy (SEM) analysis of the coating section revealed a significant improvement in the dispersion of HZB in the resin compared to hydroxyapatite (HAp), resulting in a notable reduction in coating defects upon the addition of HZB. Electrochemical impedance spectroscopy (EIS) tests demonstrated that HZB/EP maintained a high low-frequency impedance value even after immersion in a 3.5% NaCl solution for 40 days, exhibiting an impedance magnitude 4–5 orders of magnitude higher than Pure EP. Additionally, scratch and salt spray tests validated the release and action process of the corrosion inhibitor BTA. This study presents a novel strategy for the development of multifunctional anticorrosive coatings.
研究领域:
材料科学
·
腐蚀与防护
·
高分子化学
·
表面工程
·
功能材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Zewei Chen,Weigang Wang,Jianguo Duan,Feipeng Qian,Yuanpeng Cao,Jingjing He,Ding Wang,Peng Dong,Yingjie Zhang
Among various lithium-ion batteries cathode materials , olivine-type phosphate LiMnPO 4 has the advantages of high working voltage, superior theoretical energy density and high stability, however, its electronic and ionic insulation limit its application. In this work, LiMn 0.90 Fe 0.10 PO 4 /C (LMFP@C) nano composites are prepared via a mechanochemical activation assisted carbothermal reduction method, and the consequence of carbon coating amount on the electrochemical performance of the materials is discussed in detail. The results of physical and chemical properties analysis show that the mechanical liquid activation process can effectively reduce the particle size of the precursor to nanometer scale and make the raw material mixed evenly. The high crystallinity , particle nanometrization and uniform carbon coating enable LMFP@C composites with excellent electrochemical performance even when a small amount of carbon coating is introduced. Under an optimizing coated carbon amount of 2.5 wt%, the material showed ∼4.0 V and ∼3.6 V voltage platforms at 0.1, 0.2, 0.5, 1, and 2C, and released discharge specific capacities of ∼155 mAh·g −1 and ∼140 mAh·g −1 at 0.1 and 1C, respectively. It also shows optimal cycling stability with a capacity retention rate ∼100% after 100 cycles at 2C.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
无机非金属材料
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2014
·Vol. 43
·期 16
·6132-6138
·
IF 4.097
Wanyuan Li,Rong-Jun Xie,Tianliang Zhou,Lihong Liu,Yuejin Zhu
The promising green oxynitride phosphor, Ba3Si6O12N2:Eu2+, was synthesized at 1350 °C for 5 hours under a reducing N2/H2 (5%) atmosphere by using the solid-state reaction method. The phase purity was investigated by varying the nominal compositions, and the pure phase was achieved by carefully controlling the Si/Ba and O/Ba ratios. The phosphor displayed a broad excitation band spanning from the ultraviolet (UV) to the blue spectral region, and showed a single symmetrical emission band peaking at 525 nm with a full width at half maximum (FWHM) of ∼68 nm. The as-prepared green phosphor exhibited a small thermal quenching, which remained 90% of the initial emission intensity when measured at 200 °C. The internal and external quantum efficiencies measured under 450 nm excitation were 68 and 38%, respectively. Color temperature-tunable white LEDs with a high color rendering index of Ra = 88–94 were attained by combining the prepared green phosphor and a red phosphor Sr2Si5N8:Eu2+ with a blue LED chip.
研究领域:
材料科学
·
无机化学
·
发光材料
·
半导体照明
·
光电工程
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 24
·8414-8424
·
IF 4
Tao Tan,Ran Pang,Shangwei Wang,Haiyan Wu,Jiutian Wang,Su Zhang,Chengyu Li,Hongjie Zhang
Cr3+-activated phosphors with high quantum efficiency show excellent promise in the field of near-infrared (NIR) phosphor converted light-emitting diodes (pc-LEDs). Here, we design an annealing program for Cr3+-doped phosphors containing variable valence elements that cannot be prepared in a reducing atmosphere to enhance their luminescence efficiency and thermal stability. A novel phosphor, Li2Mg3SnO6:Cr3+, developed by this annealing design, containing variable valence element Sn, exhibits higher quantum efficiency and better thermal stability than the one prepared by the conventional solid-state reaction. The Li2Mg3SnO6:0.03Cr3+ sample exhibits broadband NIR emission with a full width at half-maximum (FWHM) of 201 nm. After annealing, the internal quantum efficiency (IQE) and external quantum efficiency (EQE) of the Li2Mg3SnO6:0.03Cr3+ sample are enhanced from 48.5% to 84.7% and from 22.7% to 32.6%, respectively, and the thermal quenching temperature at which the luminescence intensity of the phosphor reduces to half of its initial value is promoted from ∼400 K to ∼425 K. The luminescence intensity of the optimized Li2Mg3SnO6:0.03Cr3+ sample at 425 K (∼152 °C) remains 49.2% of its initial intensity at 300 K. A NIR pc-LED is fabricated by combining the optimized Li2Mg3SnO6:0.03Cr3+ sample with a blue LED (455 nm blue chip), and the NIR radiant fluxes of 3.676 mW (at 10 mA) and 29.21 mW (at 100 mA), as well as a maximum NIR photoelectric efficiency of 14.2%, are obtained. The results show that this novel phosphor has great application potential in NIR pc-LEDs, and the annealing design exhibits huge potential for improving the optical properties of Cr3+-activated phosphors.
研究领域:
材料科学
·
光学工程
·
固体物理
·
光电子学
·
无机化学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2024
·Vol. 53
·期 35
·14648-14655
·
IF 3.5
Hong Su,Cong Dou,Fan Dou,Wen Li,Jiachen Li,Xiaolian Chao,Zupei Yang,Xiaoming Wang,Huan Jiao
The efficiency of silicon solar cells is still lower than theoretical values, partly due to their inability to utilize the ultraviolet and infrared portions of the solar spectrum. Herein, a novel method using a KCa2Mg2(VO4)3 phosphor with a down-shift effect to improve the photovoltaic performance of silicon solar cells and enhance the utilization of UV light in standard p-type silicon solar cells is proposed. The synthesized phosphors were mixed with an ethylene vinyl acetate (EVA) copolymer and pressed into a film, which was subsequently encapsulated in monocrystalline silicon solar cells. The results show that the addition of this film notably enhanced the photovoltaic performance of the silicon solar cells; the current density was increased by 2.89% (from 33.20 to 34.16 mA cm−2), and the photovoltaic conversion efficiency was improved by 5.69% (from 15.11% to 15.97%) at the optimal concentration compared to bare cells.
研究领域:
材料科学
·
光伏技术
·
无机功能材料
·
能源材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·Vol. 50
·期 6
·9753-9761
·
IF 5.2
Li Li,Haoliang Yang,Yongjie Wang,Faling Ling,Xianju Zhou,Guotao Xiang,Zhongmin Cao,Sha Jiang,Zhiyu Yang,Yongbin Hua
Novel Ca 2 ScNbO 6 (CSNO): Cr 3+ phosphors were synthesized through a solid-phase method. The crystal structures, luminescence performances, and applications were introduced in this work. The optimized doping concentration was found with a Cr 3+ concentration of 0.01 mol. Under the 336 nm excitation, the recorded photoluminescence spectrum in the range of 650–1300 nm indicated that the obtained sample can emit a broad near-infrared emission with a dominant peak of 858 nm while the full width at half maximum (FWHM) was determined to be 191 nm. To gain a deeper comprehension of the luminescent properties, the crystal field strength was investigated as Dq/B = 2.03, and the electron-phonon coupling for parameter S was calculated to be about 2.01. As for the potential application, utilizing the variable temperature decay lifetime technique, the relative sensitivity (S R ) was approximately 1.16% K −1 at 387 K, which can be promised for utilization in optical temperature measurement. On the other hand, a near-infrared phosphor-converted lighting-emitting diode ( Pc -LED) was fabricated for night vision. Eventually, the security ink based on the obtained sample was made for use in the anti-counterfeiting field.
研究领域:
材料科学
·
光学工程
·
无机化学
·
功能材料
·
生物医学工程
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2023
·
IF 5.4
Zhihao Zhang,Huimin Li,Ran Pang,Wenjing Wang,Da Li,Lihong Jiang,Su Zhang,Hongjie Zhang
Phosphor-converted light emitting diodes (pc-LEDs) are essential for current lighting and display areas because of their unique properties of being uncomplicated, durable and economical. In previous studies, Pr 3+ doped red-emitting phosphors have attracted enormous research interest due to their high color purity. However, their photoluminescence excitation (PLE) spectra are always hard to be combined with LED chips. This mismatch is a great obstacle to achieve Pr 3+ phosphors utilizing in LED devices. Here, to circumvent this issue, Pr 3+ -doped Ca 3 MgTiGe 3 O 12 (CMTG) red-emitting phosphor was optimized with PLE band shifting from 330 nm to 360 nm after tuning with Bi 3+ co-doping based on the structure and phosphorescence properties. The chip-matched excitation makes it a good candidate for white LEDs (wLEDs) fabrication to improve the output quality of device. Meanwhile, the high color purity of 93.02 % was obtained, which is conducive to widening the color gamut of backlight display applications. The photoluminescence (PL) spectra, fluorescence lifetime, and X-ray photoelectron spectroscopy (XPS) analysis were employed and discussed in detail to explain the role of Bi 3+ played in the system. Finally, wLEDs were fabricated with CMTG:Pr 3+ , Bi 3+ , showing a high color rendering index (Ra) of 94.4. And the color gamut covers ∼80 % of the National Television System Committee (NTSC) standard, suggesting great potential for applications of wLEDs and backlight display.
研究领域:
材料科学
·
发光材料
·
固态照明
·
显示技术
·
无机化学
·
光电子学
✓ 已验证
DOI
高影响因子
Laser & Photonics Reviews
·
2023
·Vol. 18
·期 1
·2300732
·
IF 11
Zhuowei Li,Ge Zhu,Shanshan Li,Wen Xu,Qingfeng Bian,Yan Cong,Ming He,Xixian Luo,Shuangyu Xin,Bin Dong
The burgeoning phosphor-converted near-infrared light-emitting diodes (pc-NIR LEDs) have important applications in special illumination and spectroscopy analysis. However, the development of efficient NIR-emitting phosphors with high performance is still a challenge. In this work, a chemical unit co-substitution strategy is proposed to realize the excitation transition regulation and successfully achieve high-performance NIR luminescence in Ca 3- y Na y Mg 1- y Sb 2- x Al 2+ y O 12 : x Cr 3+ (0 ≤ x ≤ 0.05, 0 ≤ y ≤ 1) garnet-type solid solution phosphors. Through the excitation transition modulation from the 4 A 2 ground state to the 4 T 1 ( 4 P) and 4 T 1 ( 4 F) excitation state, the excitation intensity at the blue light region is largely enhanced by 25.6 times. Moreover, the NIR-emitting efficiency and thermal stability are improved, with the optimal luminescence internal quantum efficiency of 90.6% and thermal stability of 97%@423 K, without any flux-assisted sintering or reduction atmosphere protection. The structure regulation induced small Stokes shift, weak electron-phonon coupling effect, and decreased non-radiative transition are responsible for the excellent NIR-emitting performance. Finally, the NIR pc-LED is fabricated with photoelectric efficiencies of 18.7%@100 mA and NIR output powers of 63 mW@100 mA, presenting potential applications in nondestructive internal defect detection, veins imaging, and night vision surveillance.
研究领域:
材料科学
·
光学工程
·
固体化学
·
发光材料
·
半导体器件
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 16
·13418-13425
·
IF 3.289
Fubin Luo,Kun Wu,Mangeng Lu
The influence of polybenzoxazine modified ammonium polyphosphate (BMAPP) on the thermal behavior and flame retardancy of a rigid polyurethane foam (PU) are investigated via thermogravimetric analysis (TG), TG coupled with infrared spectroscopy (TG-FTIR), UL-94 vertical burning testing and limit oxygen index (LOI). The TG testing results indicate that BMAPP can enhance the thermal stability of PU, both under air and nitrogen conditions. The initial degradation temperature of the BMAPP/PU composites is 264 °C in air, which is 22 °C and 30 °C higher than that of ammonium polyphosphate (APP)/PU composites and neat PU, respectively. The reason might be attributed to the better dispersion and compatibility of BMAPP particles in PU compared with APP, which can prevent the PU chain from degrading at low temperatures. The LOI value results demonstrate that BMAPP has higher flame retardancy in PU than APP. Residue analysis implies that polybenzoxazine is partially converted into Si–O as char residue during combustion.
研究领域:
高分子材料科学
·
阻燃材料
·
热功能材料
·
复合材料学
·
材料化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 15
·8026-8038
·
IF 2.936
Shuli Liu,Zhengyang Duan,Changhua He,Xiaojun Xu,Tianguo Li,Yuhuan Li,Xuan Li,Yao Wang,Longqian Xu
Phosphate-modified baker's yeast (PMBY) was prepared, and used as a novel bio-sorbent for the adsorption of Pb2+ from aqueous solution. The influencing factors, absorption isotherms, kinetics, and mechanism were investigated. The scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) characterization and elemental analysis of PMBY showed that phosphate groups were successfully grafted onto the surface of yeast. The kinetic studies suggested that the adsorption process followed a pseudo-second-order chemisorption. The adsorption process of Pb2+ using PMBY was spontaneous and endothermic. Furthermore, the adsorption of Pb2+ on PMBY can rapidly achieve adsorption equilibrium (in just 3 min), and the maximum adsorption capacity of Pb2+ on PMBY was found to be 92 mg g−1 at 30 °C, which was about 3 times that of the pristine baker's yeast. The suggested mechanism for Pb2+ adsorption on PMBY was based upon ion-exchange, electrostatic interaction and chelation between the phosphate groups and Pb2+. However, compared with the pristine baker's yeast, the higher capacity and rapid adsorption of PMBY for Pb2+ was mainly due to the chelation and electrostatic interactions between the phosphate groups and Pb2+. In addition, the regeneration experiments indicated that the PMBY was easily recovered through desorption in 0.01 M HCl, and that PMBY still exhibited 90.77% of the original adsorption capacity for Pb2+ after five regeneration cycles. These results showed the excellent regeneration capability of PMBY for Pb2+ adsorption. PMBY has shown significant potential for the removal of heavy metals from aqueous solution due to its rapid adsorption, high-capacity and facile preparation.
研究领域:
环境科学
·
生物化学
·
环境污染治理
·
重金属吸附
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）