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Luminescence Properties of Green-emitting Phosphors-Sr4Al14O25:Eu2+ for LED Applications
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作者 Wei-Ren Liu Chun Che Lin +3 位作者 Yi-Chen Chiu Yao-Tsung Yeh Shyue-Ming Jang Ru-Shi Liu 《Journal of Chemistry and Chemical Engineering》 2011年第7期638-643,共6页
A highly intense green-emitting phosphor of Eu2+-doped Sr4Al14O25 (SAE:Eu2+) was synthesized by a solid state reaction. In this study, XRD, PL/PLE, QE, thermal stability and LED package tests are systematically c... A highly intense green-emitting phosphor of Eu2+-doped Sr4Al14O25 (SAE:Eu2+) was synthesized by a solid state reaction. In this study, XRD, PL/PLE, QE, thermal stability and LED package tests are systematically carried out and investigated. The optimized-composition of (Sro 92Eu0.08)4Al14025 exhibited a green emission peak at 497 nm under excitation wavelength of 400 nm, giving the chromaticity coordinates of (0.14, 0.35) with excellent quantum efficiency (98%) compared to those of other green-commodities, such as Ba2SiO4:Eu2+ (90%) and BaMgAl10O17:EU2+, Mn2+ (92%). The results demonstrated that SAE:Eu2+ could be a potential candidate as the NUV-pumping phosphor for applications in light-emitting diodes (LEDs). 展开更多
关键词 LEDS phosphors Sr4Al14025 LUMINESCENCE EU2+.
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Structural and Luminescent Properties of Mg_(0.25-x)Al_(2.57)O_(3.79)N_(0.21):xMn^(2+)Green-Emitting Transparent Ceramic Phosphor
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作者 郝留成 MIAO Xiaojun +4 位作者 LI Kai ZHONG Jianying 涂兵田 YANG Zhangfu 王皓 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第3期533-540,共8页
A series of spinel-type Mg_(0.25-x)Al_(2.57)O_(3.79)N_(0.21):xMn^(2+)(MgAlON:xMn^(2+))phosphors were synthesized by the solid-state reaction route.The transparent ceramic phosphors were fabricated by pressureless sint... A series of spinel-type Mg_(0.25-x)Al_(2.57)O_(3.79)N_(0.21):xMn^(2+)(MgAlON:xMn^(2+))phosphors were synthesized by the solid-state reaction route.The transparent ceramic phosphors were fabricated by pressureless sintering followed by hot-isostatic pressing(HIP).The crystal structure,luminescence and mechanical properties of the samples were systematically investigated.The transparent ceramic phosphors with tetrahedrally coordinated Mn^(2+)show strong green emission centered around 515 nm under blue light excitation.As the Mn^(2+)concentration increases,the crystal lattice expands slightly,resulting in a variation of crystal field and a slight red-shift of green emission peak.Six weak absorption peaks in the transmittance spectra originate from the spin-forbidden ^(4)T_(1)(^(4)G)→^(6)A_(1) transition of Mn^(2+).The decay time was found to decrease from 5.66 to 5.16 ms with the Mn^(2+)concentration.The present study contributes to the systematic understanding of crystal structure and properties of MgAlON:xMn^(2+)green-emitting transparent ceramic phosphor which has a potential application in high-power light-emitting diodes. 展开更多
关键词 transparent ceramic phosphor green emission MGALON PHOTOLUMINESCENCE
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Achieving Narrowed Bandgaps and Blue-Light Excitability in Zero-Dimensional Hybrid Metal Halide Phosphors via Introducing Cation-Cation Bonding
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作者 Pengfei Fu Shining Geng +7 位作者 Ruixiang Mi Ranyun Wu Guangya Zheng Binbin Su Zhiguo Xia Guangda Niu Jiang Tang Zewen Xiao 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第1期294-300,共7页
Zero-dimensional(0D)hybrid metal halides,which consist of organic cations and isolated inorganic metal halide anions,have emerged as phosphors with efficient broadband emissions.However,these materials generally have ... Zero-dimensional(0D)hybrid metal halides,which consist of organic cations and isolated inorganic metal halide anions,have emerged as phosphors with efficient broadband emissions.However,these materials generally have too wide bandgaps and thus cannot be excited by blue light,which hinders their applications for efficient white light-emitting diodes(WLEDs).The key to achieving a blue-light-excitable 0D hybrid metal halide phosphor is to reduce the fundamental bandgap by rational chemical design.In this work,we report two designed hybrid copper(I)iodides,(Ph_(3)MeP)_(2)Cu_(4)I_(6)and(Cy_(3)MeP)_(2)Cu_(4)I_(6),as blue-light-excitable yellow phosphors with ultrabroadband emission.In these compounds,the[Cu_(4)I_(6)]^(2-)anion forms an I6 octahedron centered on a cationic Cu_(4)tetrahedron.The strong cation-cation bonding within the unique cationic Cu_(4)tetrahedra enables significantly lowered conduction band minimums and thus narrowed bandgaps,as compared to other reported hybrid copper(I)iodides.The ultrabroadband emission is attributed to the coexistence of free and self-trapped excitons.The WLED using the[Cu_(4)I_(6)]^(2-)anion-based single phosphor shows warm white light emission,with a high luminous efficiency of 65 Im W^(-1)and a high color rendering index of 88.This work provides strategies to design narrow-bandgap 0D hybrid metal halides and presents two first examples of blue-light-excitable 0D hybrid metal halide phosphors for efficient WLEDs. 展开更多
关键词 blue-light-excitable cation-cation bonding hybrid metal halide phosphor ZERO-DIMENSIONAL
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Fabrication of YAG:Ce^(3+) and YAG:Ce^(3+),Sc^(3+) Phosphors by Spark Plasma Sintering Technique
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作者 周卫新 娄朝刚 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第2期255-260,共6页
In this study,a single-doped phosphors yttrium aluminum garnet(Y_(3)Al_(5)O_(12),YAG):Ce^(3+),single-doped YAG:Sc^(3+),and double-doped phosphors YAG:Ce^(3+),Sc^(3+) were prepared by spark plasma sintering(SPS)(lower ... In this study,a single-doped phosphors yttrium aluminum garnet(Y_(3)Al_(5)O_(12),YAG):Ce^(3+),single-doped YAG:Sc^(3+),and double-doped phosphors YAG:Ce^(3+),Sc^(3+) were prepared by spark plasma sintering(SPS)(lower than 1 200℃).The characteristics of synthesized phosphors were determined using scanning electron microscopy(SEM),X-ray diffraction(XRD),and fluorescence spectroscopy.During SPS,the lattice structure of YAG was maintained by the added Ce^(3+) and Sc^(3+).The emission wavelength of YAG:Ce^(3+) prepared from SPS(425-700 nm) was wider compared to that of YAG:Ce^(3+) prepared from high-temperature solid-state reaction(HSSR)(500-700 nm).The incorporation of low-dose Sc^(3+) in YAG:Ce^(3+) moved the emission peak towards the short wavelength. 展开更多
关键词 high-temperature solid-state reaction spark plasma sintering yttrium aluminum garnet phosphors
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Synthesis and Luminescence Improvement of CaAlSiN_(3) Phosphors Doped with Eu^(2+) and Mn^(2+) for White LEDs
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作者 WEI Dong SU Wenxia 《发光学报》 EI CAS CSCD 北大核心 2024年第10期1656-1666,共11页
Eu^(2+) and Mn^(2+) co-activated CaAlSiN_(3) red phosphors were produced using the solid-state reaction tech⁃nique in a N2 environment.Excitation spectra,emission spectra,and diffuse reflection spectra were used to st... Eu^(2+) and Mn^(2+) co-activated CaAlSiN_(3) red phosphors were produced using the solid-state reaction tech⁃nique in a N2 environment.Excitation spectra,emission spectra,and diffuse reflection spectra were used to study the luminescence characteristics,energy gap,and thermal stability in detail.CaAlSiN_(3)∶Eu^(2+) exhibits an extended emission band when stimulated with 450 nm blue light,which is caused by the 4f65d to 4f7 transition of Eu^(2+).Similar⁃ly,CaAlSiN_(3)∶Mn^(2+) displays a wide emission band centered at 628 nm,which results from Mn^(2+)’s transition from 4T1(4G) to 6A1(6S).When the ions of Mn^(2+)were combined into CaAlSiN_(3)∶Eu^(2+),the photoluminescence intensity of Eu^(2+ )was greatly boosted because there was energy transfer and co-emission between Mn^(2+) and Eu^(2+).Beyond that,CaAlSiN_(3)∶Eu^(2+),Mn^(2+) emerges with splendid thermostability and high quantum efficiency,the quenching temperature surpasses 300℃,and the internal quantum efficiency is determined to be around 84.9%.The white LED was pack⁃aged with a combination of CaAlSiN_(3)∶Eu^(2+),Mn^(2+),LuAG∶Ce3+ and a blue chip.At a warm white-light corresponding color temperature(3009 K) with CIE coordinates(0.4223,0.3748),the color rendering index Ra has reached 93.2.CaAlSiN_(3)∶Eu^(2+),Mn^(2+) would have great application potential as a red-emitting phosphor for white LEDs. 展开更多
关键词 energy transfer silicon nitrides CaAlSiN_(3)∶Eu^(2+) Mn^(2+) red phosphor
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Vacuum Ultraviolet Spectral Investigations on Green-Emitting Ca(La,Gd)_4Si_3O_(13):Tb^(3+) Phosphors for PDP Applications
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作者 吴佳蓁 陈炳铭 陈登铭 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第z2期179-182,共4页
In an effort to develop new green-emitting PDP phosphors with high efficiency, investigated were the synthesis, VUV photoluminescence (PL) spectra, optical properties, and chromaticity of Ca(La1-x-yTbxGdy. )4Si3O13 ph... In an effort to develop new green-emitting PDP phosphors with high efficiency, investigated were the synthesis, VUV photoluminescence (PL) spectra, optical properties, and chromaticity of Ca(La1-x-yTbxGdy. )4Si3O13 phosphors by using synchrotron radiation. Upon analysis of the VUV spectroscopic and chromaticity investigations on the new greenemitting VUV phosphors, were an optimized composition achieved. The PLE spectral studies show that Ca ( La1-x-y TbxGdy)4Si3O13 exhibit significant absorption in the VUV range. The VUV PL intensity was found to enhance with Gd3+-doping. Furthermore, the 1931 CIE chromaticity coordinates of Ca(La,Gd)4Si3O13:Tb were found to be (0.286, 0.548), as compared to (0.230, 0.712) for Zn2SiP4:Mn2+ as a reference. The potential application of Ca(La,Gd)4Si3O13:Tb as a new green-emitting PDP phosphor are being currently improving and evaluating. 展开更多
关键词 phosphors VUV spectra CIE chromaticity coordinates PDP
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Luminescence Properties of Green-Emitting Phosphor (Ba_(1-x),Sr_x_2SiO_4∶Eu^(2+) for White LEDS 被引量:17
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作者 刘红利 何大伟 沈芳 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第1期121-124,共4页
The (Ba1- x, Srx ) 2 SiO4 : EU^2+ green-emitting phosphors were synthesized by conventional solid-state reaction in a CO-reductive atmosphere, and their luminescent properties were investigated. The XRD data show ... The (Ba1- x, Srx ) 2 SiO4 : EU^2+ green-emitting phosphors were synthesized by conventional solid-state reaction in a CO-reductive atmosphere, and their luminescent properties were investigated. The XRD data show that the Ba/Sr ratio not only affects the lattice parameters, but also influences the emission peak. The excitation spectra indicate that this phosphor can be effectively excited by UV light from 370 to 470 nm. The emission band is due to the 4f^65d^1→4f^7 transition of the Eu^2+ ion. With an increase in x, the emission band shifts to longer wavelength and the reason was discussed. The emission spectra exhibit a satisfactory green performance under different excitation wavelength(380,398,412,420,460 nm). (Ba1- x, Srx ) 2 SiO4 : EU^2+ is a promising phosphor for green white-lighting-emission diode by ultraviolet chip. 展开更多
关键词 phosphor silicate LUMINESCENCE rare earths
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Mn^(4+) activated phosphors in photoelectric and energy conversion devices
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作者 Yang Ding Chunhua Wang +8 位作者 Lang Pei Qinan Mao Sateesh Bandaru Runtian Zheng Soumyajit Maitra Meijiao Liu Li-Hua Chen Bao-Lian Su Jiasong Zhong 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第11期277-299,I0007,共24页
Owing to their high luminous efficiency and tunable emission in both red light and far-red light regions,Mn^(4+)ion-activated phosphors have appealed significant interest in photoelectric and energy conversion devices... Owing to their high luminous efficiency and tunable emission in both red light and far-red light regions,Mn^(4+)ion-activated phosphors have appealed significant interest in photoelectric and energy conversion devices such as white light emitting diode(W-LED),plant cultivation LED,and temperature thermometer.Up to now,Mn^(4+)has been widely introduced into the lattices of various inorganic hosts for brightly redemitting phosphors.However,how to correlate the structure-activity relationship between host framework,luminescence property,and photoelectric device is urgently demanded.In this review,we thoroughly summarize the recent advances of Mn^(4+)doped phosphors.Meanwhile,several strategies like co-doping and defect passivation for improving Mn^(4+)emission are also discussed.Most importantly,the relationship between the protocols for tailoring the structures of Mn^(4+)doped phosphors,increased luminescence performance,and the targeted devices with efficient photoelectric and energy conversion efficiency is deeply correlated.Finally,the challenges and perspectives of Mn^(4+)doped phosphors for practical applications are anticipated.We cordially anticipate that this review can deliver a deep comprehension of not only Mn^(4+)luminescence mechanism but also the crystal structure tailoring strategy of phosphors,so as to spur innovative thoughts in designing advanced phosphors and deepening the applications. 展开更多
关键词 Mn^(4+) activator phosphor Structure tailoring Photoelectric device Energy conversion
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Synthesis and Luminescence Properties of Green-emitting Phosphor CaSc_(2)O_(4):Ce^(3+) 被引量:1
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作者 LI Zhao WU Kunyao +3 位作者 WANG Yanan CAO Jing WANG Yongfeng LU Yuanyuan 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2022年第4期591-594,共4页
Using CaCO_(3),Sc_(2)O_(3),and CeO_(2) as raw materials,we prepared the CaSc_(2)O_(4):Ce^(3+)green phosphors for white light LEDs via a high-temperature solid-phase method in a reducing atmosphere.X-ray diffraction(XR... Using CaCO_(3),Sc_(2)O_(3),and CeO_(2) as raw materials,we prepared the CaSc_(2)O_(4):Ce^(3+)green phosphors for white light LEDs via a high-temperature solid-phase method in a reducing atmosphere.X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM),fluorescence spectroscopy and other means were used to characterize the phase structure,apparent morphology,and photoluminescence properties of the product.CaSc_(2)O_(4) was synthesized under a reducing atmosphere(95%N_(2)+5%H_(2))at 1400℃ for 4 hours.Upon excitation with a blue light(450 nm wavelength),CaSc_(2)O_(4):Ce^(3+)displays a broadband green emission peak at 525 nm.The color coordinates of CaSc_(2)O_(4):7%Ce^(3+)emission peak are(0.3712,0.5940),and the product morphology is 1μm granular.Hence,it acts as a green phosphor suitable for white LEDs that can be excited by blue light. 展开更多
关键词 WLED CaSc_(2)O_(4):Ce^(3+) phosphor luminescence properties
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Properties of Self-recoverable Mechanoluminescence Phosphor Ca_(5)Ga_(6)O_(14)∶Eu^(3+) and Its Information Encryption Application
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作者 ZHANG Ting WANG Zhijun +3 位作者 WANG Dawei ZHAO Jinxin YANG Zhiping LI Panlai 《发光学报》 EI CAS CSCD 北大核心 2024年第9期1445-1455,共11页
A novel self-recoverable mechanoluminescent phosphor Ca_(5)Ga_(6)O_(14)∶Eu^(3+) was developed by the high-tem-perature solid-state reaction method,and its luminescence properties were investigated.Ca_(5)Ga_(6)O_(14)... A novel self-recoverable mechanoluminescent phosphor Ca_(5)Ga_(6)O_(14)∶Eu^(3+) was developed by the high-tem-perature solid-state reaction method,and its luminescence properties were investigated.Ca_(5)Ga_(6)O_(14)∶Eu^(3+)can produce red mechanoluminescence,and importantly,it shows good repeatability.The mechanoluminescence of Ca_(5)Ga_(6)O_(14)∶Eu^(3+) results from the piezoelectric field generated inside the material under stress,rather than the charge carriers stored in the traps,which can be confirmed by the multiple cycles of mechanoluminescence tests and heat treatment tests.The mechanoluminescence color can be turned from red to green by co-doping varied concentrations of Tb^(3+),which may be meaningful for encrypted letter writing.The encryption scheme for secure communication was devised by harnessing mechanoluminescence patterns in diverse shapes and ASCII codes,which shows good encryption performance.The results suggest that the mechanoluminescence phosphor Ca_(5)Ga_(6)O_(14)∶Eu^(3+),Tb^(3+)may be applied to the optical information encryption. 展开更多
关键词 phosphor MECHANOLUMINESCENCE self-recoverable information encryption
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Pillar effect induced by ultrahigh phosphorous/nitrogen doping enables graphene/MXene film with excellent cycling stability for alkali metal ion storage
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作者 Meng Qin Yiwei Yao +5 位作者 Junjie Mao Chi Chen Kai Zhu Guiling Wang Dianxue Cao Jun Yan 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期146-156,I0004,共12页
Graphene's large theoretical surface area and high conductivity make it an attractive anode material for potassium-ion batteries(PIBs).However,its practical application is hindered by small interlayer distance and... Graphene's large theoretical surface area and high conductivity make it an attractive anode material for potassium-ion batteries(PIBs).However,its practical application is hindered by small interlayer distance and long ion transfer distance.Herein,this paper aims to address the issue by introducing MXene through a simple and scalable method for assembling graphene and realizing ultrahigh P doping content.The findings reveal that MXene and P-C bonds have a "pillar effect" on the structure of graphene,and the P-C bond plays a primary role.In addition,N/P co-doping introduces abundant defects,providing more active sites for K^(+) storage and facilitating K^(+) adsorption.As expected,the developed ultrahigh phosphorous/nitrogen co-doped flexible reduced graphene oxide/MXene(NPrGM) electrode exhibits remarkable reversible discharge capacity(554 mA hg^(-1) at 0.05 A g^(-1)),impressive rate capability(178 mA h g^(-1) at 2 A g^(-1)),and robust cyclic stability(0.0005% decay per cycle after 10,000 cycles at 2 A g^(-1)).Furthermore,the assembled activated carbon‖NPrGM potassium-ion hybrid capacitor(PIHC) can deliver an impressive energy density of 131 W h kg^(-1) and stable cycling performance with 98.1% capacitance retention after5000 cycles at 1 A g^(-1).Such a new strategy will effectively promote the practical application of graphene materials in PIBs/PIHCs and open new avenues for the scalable development of flexible films based on two-dimensional materials for potential applications in energy storage,thermal interface,and electromagnetic shielding. 展开更多
关键词 GRAPHENE MXene phosphorous doping Pillar effect Potassium-ion batteries
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Dancing bubble sonoluminescence in phosphoric acid solution
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作者 Dexin Wang Qinghim +2 位作者 Wurihan Bao Haiying Han Naranmandula 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第11期429-435,共7页
Sonoluminescence is more distinctly observed in phosphoric and sulfuric acid,which exhibit high viscosity and lower vapor pressures relative to water.Within an 85-wt%phosphoric acid solution saturated with argon(Ar),v... Sonoluminescence is more distinctly observed in phosphoric and sulfuric acid,which exhibit high viscosity and lower vapor pressures relative to water.Within an 85-wt%phosphoric acid solution saturated with argon(Ar),variations in the light-emitting regimes of bubbles were noted to correspond with increments in the driving acoustic intensity.Specifically,the bubbles were observed to perform a dance-like motion 2 cm below the multi-bubble sonoluminescence(MBSL)cluster,traversing a 25-mm^(2) grid during the camera exposure period.Spectral analysis conducted at the beginning of the experiment showed a gradual attenuation of CN(B^(2)S–X^(2)S)emission concurrent with a strengthening of Ar(4p–4s)atom emission lines.The application of a theoretical temperature model to the spectral data revealed that the internal temperature of the bubbles escalates swiftly upon their implosion.This study is instrumental in advancing the comprehension of the underlying mechanisms of sonoluminescence and in the formulation of a dynamic model for the behavior of the bubbles. 展开更多
关键词 SONOLUMINESCENCE SPECTRUM phosphoric acid solution noble gas
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Durable hierarchical phosphorus‐doped biphase MoS_(2)electrocatalysts with enhanced H^(*)adsorption
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作者 Yongteng Qian Jianmin Yu +4 位作者 Zhiyi Lyu Qianwen Zhang Tae Hyeong Lee Huan Pang Dae Joon Kang 《Carbon Energy》 SCIE EI CAS CSCD 2024年第4期104-114,共11页
Phase engineering is an efficient strategy for enhancing the kinetics of electrocatalytic reactions.Herein,phase engineering was employed to prepare high‐performance phosphorous‐doped biphase(1T/2H)MoS_(2)(P‐BMS)na... Phase engineering is an efficient strategy for enhancing the kinetics of electrocatalytic reactions.Herein,phase engineering was employed to prepare high‐performance phosphorous‐doped biphase(1T/2H)MoS_(2)(P‐BMS)nanoflakes for hydrogen evolution reaction(HER).The doping of MoS_(2)with P atoms modifies its electronic structure and optimizes its electrocatalytic reaction kinetics,which significantly enhances its electrical conductivity and structural stability,which are verified by various characterization tools,including X‐ray photoelectron spectroscopy,high‐resolution transmission electron microscopy,X‐ray absorption near‐edge spectroscopy,and extended X‐ray absorption fine structure.Moreover,the hierarchically formed flakes of P‐BMS provide numerous catalytic surface‐active sites,which remarkably enhance its HER activity.The optimized P‐BMS electrocatalysts exhibit low overpotentials(60 and 72 mV at 10 mA cm^(−2))in H_(2)SO_(4)(0.5 M)and KOH(1.0 M),respectively.The mechanism of improving the HER activity of the material was systematically studied using density functional theory calculations and various electrochemical characterization techniques.This study has shown that phase engineering is a promising strategy for enhancing the H*adsorption of metal sulfides. 展开更多
关键词 1T/2H MoS_(2) density functional theory ELECTROCATALYSTS phase engineering phosphorous doping
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The KEu(WO_(4))_(2)Red Phosphor Co-doped with Li^(+)and SO_(4)^(2-)for Synergistic Enhancement of High Efficiency and Thermal Stability
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作者 ZHU Hai YUAN Mengzhen +3 位作者 ZHENG Liangjian FAN Jia PENG Xinhao ZHANG Jun 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第6期1391-1396,共6页
A series of tungstate red phosphors K_(1-x)Li_(x)Eu(WO_(4))_(2-y)(SO_(4))_(y)were successfully prepared by sol-gel method,and the effects of the introduction of Li~+and SO_(4)^(2-)on the fluorescence intensity and the... A series of tungstate red phosphors K_(1-x)Li_(x)Eu(WO_(4))_(2-y)(SO_(4))_(y)were successfully prepared by sol-gel method,and the effects of the introduction of Li~+and SO_(4)^(2-)on the fluorescence intensity and thermal quenching properties of the prepared K_(1-x)Li_(x)Eu(WO_(4))_(2-y)(SO_(4))_(y)phosphors were investigated.The X-ray diffraction data show that the prepared(Li^(+)and SO_(4)^(2-))-doped KEu(WO_(4))_(2)phosphors have a monoclinic tetragonal structure.In addition,the emission intensities of all the observed emission peaks change significantly with the increase of Li~+doping concentration,especially the intensity of the emission peaks at 615 nm fluctuated significantly and reached the maximum at x=0.3 and y=0.2.The K_(1-x)Li_(x)Eu(WO_(4))_(2-y)(SO_(4))_(y)phosphors are found to have the highest fluorescence intensity at x=0.3 and y=0.2.Moreover,the K_(0.7)Li_(0.3)Eu(WO_(4))_(1.8)(SO_(4))_(0.2)phosphor has better thermal quenching properties and luminescence efficiency,and the experimental results indicates that the fluorescence intensity and thermal burst performance of KEu(WO_(4))_(2)red phosphor could be effectively improved by using low-cost bionic doping of Li^(+)and SO_(4)^(2-). 展开更多
关键词 sol-gel fluorescence phosphors KEu(WO_4)_2 Li~+ SO_4~(2-)
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Development of a Novel Green-Emitting Phosphate Phosphor KSrY(PO<sub>4</sub>)<sub>2</sub>:Eu<sup>2+</sup>
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作者 Akiko Saito Hideki Kato +2 位作者 Makoto Kobayashi Yasushi Sato Masato Kakihana 《Optics and Photonics Journal》 2013年第6期19-24,共6页
In this study, fluorescence characteristics were evaluated by synthesizing Eu2+ doped samples for phosphates of various compositions. The study led to a green light emitting KSrY(PO4)2:Eu2+, which is rare for a phosph... In this study, fluorescence characteristics were evaluated by synthesizing Eu2+ doped samples for phosphates of various compositions. The study led to a green light emitting KSrY(PO4)2:Eu2+, which is rare for a phosphate phosphor. KSrY(PO4)2:Eu2+ had an excitation band between 250 and 450 nm and emitted green light, reaching an emission maximum at 520 nm. As this result suggests that excitation by a near-ultraviolet LED is possible, KSrY(PO4)2:Eu2+ could be useful as a phosphor for white LEDs. 展开更多
关键词 PHOSPHATE phosphor Eu2+-Activation Green Emission
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YAG∶Ce Phosphors for WLED via Nano-Pesudoboehmite Sol-Gel Route 被引量:15
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作者 张纳 王达健 +3 位作者 李岚 蒙延双 张晓松 明楠 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第3期294-297,共4页
The sub-micron sized YAG : Ce phosphors were synthesized via a modified sol-gel method by peptizing nano-pesudoboehmite particulate. It is found that YAG phase from the dried gel powders appears at 1000 ℃ then the p... The sub-micron sized YAG : Ce phosphors were synthesized via a modified sol-gel method by peptizing nano-pesudoboehmite particulate. It is found that YAG phase from the dried gel powders appears at 1000 ℃ then the pure YAG phase exists at a relatively lower sintering temperature of 1400 ℃. The smaller sizes of phosphors in the ranges of 1 - 3 μm are obtained due to the contribution of seeding effects of nano-sized alumina particles to strengthen each step of the processes. Both the excitation and emission spectra of photoluminescence of the phosphor obtained at 1400 ℃ meet well with the spectroscopic requirements of the WLED phosphors. 展开更多
关键词 PSEUDO-BOEHMITE sol-gel YAG Ce phosphor WLED rare earths
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Investigations on Valence-Change Behaviors of Europium Ions in Eu-Doped Aluminate and Silicate Phosphors 被引量:3
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作者 彭明营 达宁 +4 位作者 乔延波 吴伯涛 汪晨 陈丹平 邱建荣 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第6期749-753,共5页
Compounds of Sr3Al2O6 : Eu, SrgAl14O25 : Eu, and BaZnSiO4 : Eu were synthesized by high-temperature solid state reactions. The doping Eu^3 + ions were partially reduced to Eu^2+ in Sr4Al14O25:Eu and BaZnSiOg:Eu... Compounds of Sr3Al2O6 : Eu, SrgAl14O25 : Eu, and BaZnSiO4 : Eu were synthesized by high-temperature solid state reactions. The doping Eu^3 + ions were partially reduced to Eu^2+ in Sr4Al14O25:Eu and BaZnSiOg:Eu prepared in an oxidizing atmosphere, N^2 + O2. However, such an abnormal reduction process could not be performed in Sr3Al2O6:Eu, which was also prepared in an atmosphere of N^2 + O2. Moreover, even though Sr3A1EO6:Eu was synthesized in a reducing condition CO, only part of the Eu^3 + ions was reduced to Eu^2 + . The existence of trivalent and divalent europium ions was confirmed by photoluminescent spectra. The different valence-change behaviors of europium ions in the hosts were attributed to the difference in host crystal structures. The higher the crystal structure stiffness, the easier the reduction process from Eu^3 + to Eu^2 + . 展开更多
关键词 aluminate phosphors silicate phosphors Eu^3 Eu^2 rare earths
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Preparation and luminescent properties of CaAl_2O_4:Eu^(3+),R^+(R=Li,Na,K) phosphors 被引量:4
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作者 李广环 龙涛 +5 位作者 宋艳华 高桂梅 徐吉静 安佰超 甘树才 洪广言 《Journal of Rare Earths》 SCIE EI CAS CSCD 2010年第1期22-25,共4页
CaAl2O4:Eu3+,R+(R=Li+,Na+,K+) red phosphors were synthesized by solid state reaction method.X-ray diffraction(XRD) and photoluminescence(PL) were employed to characterize their structural and luminescent properties.It... CaAl2O4:Eu3+,R+(R=Li+,Na+,K+) red phosphors were synthesized by solid state reaction method.X-ray diffraction(XRD) and photoluminescence(PL) were employed to characterize their structural and luminescent properties.It was found that the optimal sintering temperature and sintering time were 1200 °C and 4 h,respectively.The optimal concentration of doped Eu3+ was 3 mol.%.Furthermore,under ultraviolet excitation with a wavelength of 254 nm,these samples showed red luminescence which were probably attributed to... 展开更多
关键词 phosphors ALUMINATES Eu3+ PHOTOLUMINESCENCE rare earths
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Separation of Red (Y_2O_3: Eu^(3+)), Blue (Sr,Ca,Ba)_(10)(PO_4)_6Cl_2: Eu^(2+) and Green (LaPO_4:Tb^(3+),Ce^(3+)) Rare Earth Phosphors by Liquid/Liquid Extraction 被引量:4
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作者 梅光军 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2009年第3期418-423,共6页
A novel process for separation of red (Y2O3: Eu^3+), blue (Sr, Ca, Ba)10(PO4)6Cl2: Eu^2+ and green (LaPO4: Tb^3+, Ce^3+) fine tricolor phosphor powders was established. First, the green phosphor was ext... A novel process for separation of red (Y2O3: Eu^3+), blue (Sr, Ca, Ba)10(PO4)6Cl2: Eu^2+ and green (LaPO4: Tb^3+, Ce^3+) fine tricolor phosphor powders was established. First, the green phosphor was extracted and separated from three phosphor mixtures in heptane/DMF(N, N-Dimethylformamide) system using stearylamine or laurylamine (DDA) as the cationic surfactant. Then, after being treated with 99.5% ethanol, the blue and red phosphors could be separated in Heptane/DMF system in presence of 1-octanesulfonic acid sodium salt as the anionic surfactant. Satisfactory separation results have been achieved through two steps extractions with their artificial mixtures. The grades and recovery of separated products reached respectively as follows: red product was 95.3% and 90.9%, blue product was 90.0% and 95.2%, and green product was 92.2% and 91.8%. 展开更多
关键词 rare earth phosphor liquid-liquid extraction SEPARATION
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Effect of Yb^(3+) concentration on the structures and upconversion luminescence properties of Y_2O_3:Er^(3+) ultrafine phosphors 被引量:4
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作者 ZHANG Yongming LI Yanhong +2 位作者 ZHANG Yang HONG Guangyan YU Yingning 《Rare Metals》 SCIE EI CAS CSCD 2008年第6期603-607,共5页
Y2O3:Er^3+ ultrafine phosphors with a varying Yb^3+ ion concentration were prepared by a urea homogeneous precipitation method. The results of XRD show that all the samples are of a pure cubic structure and the ave... Y2O3:Er^3+ ultrafine phosphors with a varying Yb^3+ ion concentration were prepared by a urea homogeneous precipitation method. The results of XRD show that all the samples are of a pure cubic structure and the average crystallite sizes can be calculated as 45, 34, and 28 nm for Y2O3:Er^3+ ultrafine phosphors with Yb^3+ ion concentrations of 0, 10%, and 20%, respectively. The lattice constant and cell volume of the ultrafine phosphors decrease with enhancing Yb^3+ ion concentration. The upconversion luminescence spectra of all the samples were studied under 980 nm laser excitation. The strong green and red upconversion emission were observed, and attributed to the ^2H11/2→^4I15/2, ^4S3/2 → ^4I15/2 and ^4F9/2 →^4I15/2 transitions of Er^3+, respectively. The intensity of red emission increases with increasing Yb^3+ ion concentration. The effect of Yb^3+ ion concentration on the structures and upconversion luminescence mechanism were discussed. 展开更多
关键词 ultrafine phosphor ion concentration UREA homogeneous precipitation method upconversion luminescence
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