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近红外发射Lu2O3∶Mn^4+荧光粉的制备及其发光特性 预览
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作者 刘姝婷 刘春光 +3 位作者 张猛 杨健 祝汉成 刘玉学 《人工晶体学报》 EI CAS 北大核心 2019年第7期1240-1246,共7页
采用高温固态烧结方法制备了具有不同Mn^4+离子掺杂浓度的Lu2O3∶x%Mn^4+荧光粉。应用X射线衍射、荧光激发和发射光谱、X射线光电子能谱、扫描电子显微镜和发光动力学测量等手段研究了该荧光粉的微结构和发光特性与掺杂浓度的关系。实... 采用高温固态烧结方法制备了具有不同Mn^4+离子掺杂浓度的Lu2O3∶x%Mn^4+荧光粉。应用X射线衍射、荧光激发和发射光谱、X射线光电子能谱、扫描电子显微镜和发光动力学测量等手段研究了该荧光粉的微结构和发光特性与掺杂浓度的关系。实验结果表明,Mn^4+离子可掺杂到Lu2O3基质晶格中,在252nm激发下,可观察到位于695nm和712nm的近红外发射峰,其分别来源于Mn^4+离子的2E→4A2和4T2→4A2的跃迁。当Mn^4+掺杂浓度为0.1%时,可获得最大的发光强度。通过优化热处理条件(在空气气氛、1400℃温度下热处理5h),可进一步提高Lu2O3∶0.1%Mn^4+荧光粉的近红外发光强度和余辉性能。实验发现,经热处理的Lu2O3∶0.1%Mn^4+样品中,Mn^4+离子占据了Lu2O3基质中的S6和C2两种格位;具有较长寿命的近红外发光来自占据S6格位Mn^4+离子的贡献,而具有较短寿命的近红外发光则来自占据C2格位Mn^4+离子的贡献。实验表明,经高温热处理的近红外发射Lu2O3∶Mn^4+材料余辉时间大于3min,其在生物成像方面有潜在的应用前景。 展开更多
关键词 过渡族金属离子 高温固态烧结 荧光粉 光致发光
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Temperature-dependent Raman scattering and photoluminescence in YBa2Cu3O7 doped with SiO2 and Zn0.95Mn0.05O nanoparticles:comparative study
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作者 Munirah A. Al Messiere 《稀有金属:英文版》 SCIE EI CAS CSCD 2019年第8期754-763,共10页
A combined study examining the temperature dependencies of Raman scattering and photoluminescence(PL)of a YBa2 Cu3 O7(YBCO)matrix doped with SiO2(12 nm;0.01 wt%.,0.10 wt%)and Zn0.95Mn0.05O(20 nm;0.02 wt%,0.10 wt%)nano... A combined study examining the temperature dependencies of Raman scattering and photoluminescence(PL)of a YBa2 Cu3 O7(YBCO)matrix doped with SiO2(12 nm;0.01 wt%.,0.10 wt%)and Zn0.95Mn0.05O(20 nm;0.02 wt%,0.10 wt%)nanoparticles was presented.X-ray diffraction(XRD)analysis confirms that both YBCO types exhibit aperovskite structure with the orthorhombic Pmmm phase.The microstructure was examined using environmental scanning electron microscopy(ESEM).Raman scattering and photoluminescence measurements as functions of temperature were conducted in the 77-837 K range.The photoluminescence intensity is observed to decrease for the doped YBCO than for the pure YBCO,because of localized defects.The photoluminescence spectrum is primarily composed of three bands at 1.60,1.88,and 2.40 eV.A clearly pronounced correlation is observed between electronic and structural changes in the doped YBCO,which is due to the temperature,illumination,added oxygen or metal ions,and spectral parameters.The PL integrated intensity as a function of the inverse temperature was simulated using the Arrhenius model.This analysis reveals that the energy exchange between the different levels in the pure and doped YBCO was conducted via two vibration modes only,which are strongly linked to the oxygen and copper atoms in the YBCO matrix.The temperature dependencies of the modes at 340 and 500 cm-1 exhibit softening with temperature increase,resulting from microstructure control,which may be due to small concentrations of Si,Zn,and Mn substitutions at the chain Cu(1)and plane Cu(2)sites. 展开更多
关键词 Matrix YBA2CU3O7 NANOPARTICLES RAMAN scattering RAMAN modes PHOTOLUMINESCENCE spectra
氧化对单颗粒层纳米金刚石薄膜硅空位发光和微结构的影响 预览
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作者 陈隆 陈成克 +1 位作者 李晓 胡晓君 《物理学报》 SCIE EI CAS CSCD 北大核心 2019年第16期335-343,共9页
制备了单个颗粒(domain)组成的纳米金刚石薄膜,薄膜中单个颗粒由尺寸超过 100 nm 的金刚石晶粒与非晶碳复合而成.对薄膜进行氧化处理后,其硅空位色心的光致发光强度增强了 22.7 倍.扫描电镜及拉曼光谱测试结果表明,不同时间氧化后的样... 制备了单个颗粒(domain)组成的纳米金刚石薄膜,薄膜中单个颗粒由尺寸超过 100 nm 的金刚石晶粒与非晶碳复合而成.对薄膜进行氧化处理后,其硅空位色心的光致发光强度增强了 22.7 倍.扫描电镜及拉曼光谱测试结果表明,不同时间氧化后的样品中存在由尺寸超过 100 nm 的晶粒组成的花瓣状金刚石聚集体,这些金刚石在较长氧化时间下仍能保持稳定.氧化后的薄膜内非晶碳大大减少,金刚石含量增大,纳米金刚石晶粒充分暴露引起了薄膜发光强度大幅增强,其发光半峰宽为 5.6 6.0 nm.继续增加氧化时间,薄膜的光致发光会因为部分细小纳米金刚石晶粒的损失而略微降低,但是稳定的大尺寸金刚石晶粒的存在使得薄膜的发光强度依然维持在氧化前的 8.3 倍以上. 展开更多
关键词 金刚石 硅空位色心 氧化 光致发光
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对丙烯酰氧基苯甲酸的合成及其铕配合物的发光性能 预览
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作者 肖尊宏 《贵州师范大学学报:自然科学版》 CAS 2019年第5期9-12,共4页
用丙烯酸、氯化亚砜和对羟基苯甲酸为原料,合成了对丙烯酰氧基苯甲酸(PABA);以对丙烯酰氧基苯甲酸、二苯甲酰甲烷(DBM)为第一配体、邻菲罗啉(phen)为第二配体,合成了可聚合的Eu(PABA)(DBM)2Phen四元配合物,通过红外光谱(IR)、紫外光谱(... 用丙烯酸、氯化亚砜和对羟基苯甲酸为原料,合成了对丙烯酰氧基苯甲酸(PABA);以对丙烯酰氧基苯甲酸、二苯甲酰甲烷(DBM)为第一配体、邻菲罗啉(phen)为第二配体,合成了可聚合的Eu(PABA)(DBM)2Phen四元配合物,通过红外光谱(IR)、紫外光谱(UV)、元素分析和1HNMR对配体和配合物进行了表征。荧光光谱强度表明,对丙烯酰氧基苯甲酸(PABA)有利于Eu(PABA)(DBM)2Phen四元配合物的光致发光。 展开更多
关键词 对丙烯酰氧基苯甲酸(PABA) Eu(PABA)(DBM)2Phen 光致发光
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Rational design of monovalent ions (Li,Na,K) co-doped ZnAl2O4:Eu3+ nanocrystals enabling versatile robust latent fingerprint visualization
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作者 F.Femila Komahal H.Nagabhushana +4 位作者 R.B.Basavaraj G.P.Darshan Hajeebaba K.Inamdar S.C.Sharma B.Daruka Prasad 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第7期699-705,共7页
Alkali metal ions(M+ = Na+,Li+,K+) co-doped ZnAl2O4:Eu3+(5 mol%)(ZAE) nanopowders(NPs) were prepared via solution combustion route using Mimosa pudica(MP) leaves extract as a fuel. PXRD results of co-doped samples enh... Alkali metal ions(M+ = Na+,Li+,K+) co-doped ZnAl2O4:Eu3+(5 mol%)(ZAE) nanopowders(NPs) were prepared via solution combustion route using Mimosa pudica(MP) leaves extract as a fuel. PXRD results of co-doped samples enhance the crystallinity and grain growth. Photoluminescence(PL) of the prepared ZAE and ZAE:M+(M+ = Na+, Li+, K+) NPs shows intense emission peaks in the range of 550-750 nm and ascribed to 5D0→7FJ(J=0-4) transitions of Eu3+ ions, respectively. A 2-fold enhancement in PL intensity was observed in Li+ co-doped samples. The optimized ZnAl2O4:Eu3+(5 mol%), Li+(1 wt%)(ZAEL)NPs were used to visualize LFPs on various porous, semi-porous and non-porous surfaces through robust powder dusting technique. The visualized latent fingerprints(LFPs) reveal well defined level 1-3 ridge characteristics under several tests such as fingerprint aging and fresh water treatment for various time durations. The obtained results clearly evidence that the prepared NPs are quite useful for multifunctional applications such as advanced forensic and solid state lightning. 展开更多
关键词 Photoluminescence LATENT FINGERPRINTS Solid state lightning Alkali metal IONS Rare earths
自组装固体硅量子点中的粒径分布 预览
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作者 贾旭光 ZHANG Tian +1 位作者 LIN Ziyun CONIBEER Gavin 《常州大学学报:自然科学版》 CAS 2019年第5期36-41,共6页
提出了一个用来定量分析胶体硅量子点光致荧光光谱的模型,得到量子点的粒径分布,并将此方法应用于固体硅量子点材料粒径分布的分析。结果表明:与胶体硅量子点相比,固体样品中硅量子点粒径分布更宽。这可能是由于固体样品硅在结晶过程中... 提出了一个用来定量分析胶体硅量子点光致荧光光谱的模型,得到量子点的粒径分布,并将此方法应用于固体硅量子点材料粒径分布的分析。结果表明:与胶体硅量子点相比,固体样品中硅量子点粒径分布更宽。这可能是由于固体样品硅在结晶过程中水平方向缺乏约束,因此形成的量子点为椭球形。纳米硅中粒径分布太宽会导致材料带隙分布变宽。减少量子约束效应,限制了这些材料在实际中的应用。 展开更多
关键词 硅量子点 粒径分布 光伏 光致荧光
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Structural and photoluminescence properties of La^3+doped CdO nanophosphors synthesised via green mediated solution combustion route
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作者 M.S. Geetha H.N. Shivananjaiah 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第9期916-923,I0001共9页
This paper reports a facile environmentally safe green combustion synthesis method of La3+doped CdO nanoparticles(NPs)using different concentrations of Aloe vera(A.V)gel as combustible material.The crystallite size ob... This paper reports a facile environmentally safe green combustion synthesis method of La3+doped CdO nanoparticles(NPs)using different concentrations of Aloe vera(A.V)gel as combustible material.The crystallite size obtained using PXRD pattern is found to be 12-22 nm.The structural analysis was further analysed by Rietveld refinement technique.The X-ray photoelectron spectroscopy(XPS)analysis reveals the presence of two electronic states of CdO around 400 and 411 eV attributed to Cd 3 d3/2 and 3 d3/2,respectively.The photoluminescence(PL)studies were carried upon 350 nm excitation wavelength.The PL emission spectra are found to have two prominent peaks centered at 410 and 510 nm and are attributed to 5D3→7F1 and 5D1→7F0 transitions,respectively.The Commission International de l’Eclairage(CIE)chromaticity diagram reveals blue-green color emission.The correlation color temperature(CCT)value is found to be around~9793 K.The obtained results suggest that the product is quite useful for cool light emitting diode applications when doping concentration is 2 mol%. 展开更多
关键词 Green synthesis NANOSTRUCTURES PHOTOLUMINESCENCE Judd-ofelt Rare earths CDO
配合物[Zn(H2O)2(PAA)]·(H2O)2的合成及结构表征 预览
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作者 王庆源 张恩生 +2 位作者 张玉琦 王记江 鞠萍 《延安大学学报:自然科学版》 2019年第2期54-57,共4页
采用溶剂热方法,通过ZnCl2和4-(5-嘧啶基)间苯二甲酸(H2PAA)在混合溶剂DMF/H2O中反应制备得到具有光致发光性能的配合物[Zn(H2O)2(PAA)]·(H2O)2。利用X射线单晶衍射、X射线粉末衍射、傅里叶变换红外光谱和热重分析等对配合物进行... 采用溶剂热方法,通过ZnCl2和4-(5-嘧啶基)间苯二甲酸(H2PAA)在混合溶剂DMF/H2O中反应制备得到具有光致发光性能的配合物[Zn(H2O)2(PAA)]·(H2O)2。利用X射线单晶衍射、X射线粉末衍射、傅里叶变换红外光谱和热重分析等对配合物进行了充分的结构表征。采用固态荧光光谱研究了配合物的光致发光性能。X-射线单晶衍射分析表明配合物中的锌离子和PAA^2-配体中的氧原子及氮原子配位,形成具有(4,4)菱形网格形状的一维层,该一维层状结构沿c轴交错堆叠在一起形成二维多孔结构。 展开更多
关键词 金属-有机骨架配合物 光致发光 晶体结构 荧光性质
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Enhancement of luminescence intensity and spectroscopic analysis of Eu3+ activated and Li+ charge-compensated Bi2O3 nanophosphors for solid-state lighting
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作者 S.Ashwini S.C.Prashantha +1 位作者 RamachANDra Naik H.Nagabhushana 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第4期356-364,共9页
The present work reports the synthesis, characterization, photoluminescence and photocatalytic activity of Eu3+(1 mol%-11 mol%) doped and Li+(0.5 mol%-5 mol%) co-doped Bi2 O3 nanophosphors(NPs) by sonochemical method.... The present work reports the synthesis, characterization, photoluminescence and photocatalytic activity of Eu3+(1 mol%-11 mol%) doped and Li+(0.5 mol%-5 mol%) co-doped Bi2 O3 nanophosphors(NPs) by sonochemical method. The average particle size was estimated using powder X-ray diffraction(PXRD)and transmission electron microscopy(TEM) and is found to be in the range of 30-35 nm. The scanning electron microscopy(SEM) images were highly dependent on sonication time and concentration of epigallocatechin gallate(EGCG) bio-surfactant. The energy gap of doped and co-doped Bi2 O3 nanophosphors was estimated using Kubelka-Munk(K-M) function and is found to be in the range of2.9-3.08 eV. The effect of Li+ co-doping on luminescence of optimized Bi2 O3:Eu3+ was studied and is found about more than 3 fold enhancement of emission intensity. Judd-Ofelt parameters(Ω2, Ω4 and Ω6).transition probabilities(AT), quantum efficiency(η), luminescence lifetime(τrad), color chromaticity coordinates(CIE) and correlated color temperature(CCT) values were estimated from the emission spectra and are discussed in detail. The estimated CIE chromaticity co-ordinates are very close to the NTSC(National Television Standard Committee) standard value of red emission. The synthesized NPs show excellent photocatalytic activity of acid red-88 under UV-light irradiation, which can degrade 98.1% in60 min. The decreasing electron-hole pair recombination rate with quick electron transfer ability is predominantly ascribed to the balance between crystallite size, morphology, band gap, defects, surface area, etc. These results show a light for the use of sonochemical route of Bi2 O3:Eu3+:Li+ in solid state display and photocatalytic applications. 展开更多
关键词 Bi2O3:Eu3+:Li+ SONOCHEMICAL Photoluminescence CIE n CCT Photocatalysis Rare earths
光致发光与荧光传感--光化学基本原理的应用 预览
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作者 李悦 郭东升 阮文娟 《大学化学》 CAS 2019年第4期45-50,共6页
在物理化学课程教学中融入科学前沿实例可以帮助学生掌握基本原理、提高学习兴趣。光化学是物理化学课程中的重要学习内容,但该部分内容因为涉及到激发态的能量衰减过程而抽象难懂。如果在学习这部分知识时,将该部分原理在指导荧光传感... 在物理化学课程教学中融入科学前沿实例可以帮助学生掌握基本原理、提高学习兴趣。光化学是物理化学课程中的重要学习内容,但该部分内容因为涉及到激发态的能量衰减过程而抽象难懂。如果在学习这部分知识时,将该部分原理在指导荧光传感探针设计和研究作用机理方面的应用作为知识灵活运用的实例引入,则对理解和掌握所学内容大有裨益。教学时可通过对荧光传感探针的结构及作用机制、各种光物理过程对荧光发射的影响,以及基于荧光传感原理的科研成果的介绍,使学生体会到物理化学的基本原理在科学前沿中的实际应用。 展开更多
关键词 光致发光 光物理过程 荧光传感 作用机制
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Luminescence properties of near-UV excitable yellow-orange light emitting warm CaSrAl2SiO7:Sm3+ phosphors
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作者 Shweta Sharma Nameeta Brahme +1 位作者 D.P.Bisen Pradeep Dewangan 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第4期365-373,共9页
Single-phase CaSrAl2 SiO7:Sm3+ phosphors were synthesized by traditional high temperature solid state reaction method. Formation of samples and phase analysis were confirmed by X-ray diffraction technique. Morphology ... Single-phase CaSrAl2 SiO7:Sm3+ phosphors were synthesized by traditional high temperature solid state reaction method. Formation of samples and phase analysis were confirmed by X-ray diffraction technique. Morphology was done by field emission scanning electron microscopy and elemental compositions were confirmed by energy dispersive X-ray analysis. Present phosphors have tetragonal crystallography with space group P421 m. Average crystallite size was calculated by using Scherrer and Williamson-Hall method. Photoluminescence study of CaSrAl2 SiO7:Sm3+ phosphor was investigated.Under different excitation wavelengths, PL spectra consist of four emission bands at 564, 570, 601 and650 nm. The emission bands located at 564 and 570 nm are associated with the transition 4 G5/2→6 H5/2while emission bands at 601 and 650 nm are due to 4 G5/2→6 H7/2 and 4 G5/2→6 H9/2,respectively.Intense emission was obtained when phosphor was excited under 404 nm wavelength. Non-radiative energy transfer process involved in concentration quenching, was also discussed. CIE coordinate is found in yellow-orange region, hence CaSrAl2SiO7:Sm3+ phosphors emit yellow-orange light when efficiently excited by near UV(~400 nm) LED chip. Color purity and CCT of the phosphor were determined;CCT suggests that present phosphor is a good candidate as a warm yellow-orange color emitting phosphor. Effect of different heating rates and different UV exposure time on the TL glow curve of the phosphor was investigated. Activation energies and kinetic parameters for different traps were calculated by using peak shape method. TL emission spectrum was also recorded. Present article explains all the possible mechanisms associated with luminescence process in CaSrAl2 SiO7:Sm3+ phosphors. 展开更多
关键词 THERMOLUMINESCENCE Photoluminescence ALUMINOSILICATE Yellow-orange EMITTING phosphor SAMARIUM CaSrAl2SiO7:Sm3+
氮化法合成掺钇氮化铝纳米线 预览
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作者 王秋实 吴宛泽 +1 位作者 谢永辉 王维龙 《电子元件与材料》 CAS CSCD 北大核心 2019年第2期45-48,共4页
采用直流电弧等离子体辅助法,使钇铝合金(Al:Y)和氮气直接反应,成功合成了掺钇氮化铝(AlN:Y)纳米线。用XRD、SEM和拉曼光谱对所制样品的结构和形貌进行了表征,利用PL光谱和磁滞回线研究了AlN:Y纳米线的光学性质和磁性。AlN:Y纳米线长度... 采用直流电弧等离子体辅助法,使钇铝合金(Al:Y)和氮气直接反应,成功合成了掺钇氮化铝(AlN:Y)纳米线。用XRD、SEM和拉曼光谱对所制样品的结构和形貌进行了表征,利用PL光谱和磁滞回线研究了AlN:Y纳米线的光学性质和磁性。AlN:Y纳米线长度约为10μm,直径在40~50nm。纳米线的发光中心位于533nm,展现出了良好的室温铁磁性。 展开更多
关键词 AlN:Y 纳米线 稀土掺杂 光致发光 室温铁磁性 氮化法
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稀土有机配合物的研究进展及应用 预览
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作者 焦晨婕 周彦芳 +1 位作者 章红飞 钟荣 《江西化工》 2019年第2期61-65,共5页
概述了稀土有机配合物的光致发光机理,综述了β-二酮类、有机羧酸类、超分子大环类、高分子等稀土配合物种类,简单介绍了稀土有机配合物在荧光材料、发光材料、磁性材料、防伪油墨等领域的应用,并对稀土有机配合物的研究趋势及应用前景... 概述了稀土有机配合物的光致发光机理,综述了β-二酮类、有机羧酸类、超分子大环类、高分子等稀土配合物种类,简单介绍了稀土有机配合物在荧光材料、发光材料、磁性材料、防伪油墨等领域的应用,并对稀土有机配合物的研究趋势及应用前景进行了展望。 展开更多
关键词 稀土有机配合物 荧光 光致发光 应用
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Fluorescence spectra of colloidal self-assembled CdSe nano-wire on substrate of porous Al2O3/Au nanoparticles
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作者 张欣 邵丽萍 +3 位作者 彭嫚 白忠臣 张正平 秦水介 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第6期429-432,共4页
We present a self-assembly method to prepare array nano-wires of colloidal CdSe quantum dots on a substrate of porous Al2 O3 film modified by gold nanoparticles. The photoluminescence(PL) spectra of nanowires are in s... We present a self-assembly method to prepare array nano-wires of colloidal CdSe quantum dots on a substrate of porous Al2 O3 film modified by gold nanoparticles. The photoluminescence(PL) spectra of nanowires are in situ measured by using a scanning near-field optical microscopy(SNOM) probe tip with 100-nm aperture on the scanning near-field optical microscope. The results show that the binding sites from the edge of porous Al2 O3 nanopores are combined with the carboxyl of CdSe quantum dots’ surface to form an array of CdSe nanowires in the process of losing background solvent because of the gold nanoparticles filling the nano-holes of porous Al2 O3 film. Compared with the area of nonself-assembled nano-wire, the fluorescence on the Al2 O3/Au/CdSe interface is significantly enhanced in the self-assembly nano-wire regions due to the electron transfer conductor effect of the gold nanoparticles’ surface. In addition, its full width at half maximum(FWHM) is also obviously widened. The method of enhancing fluorescence and energy transfer can widely be applied to photodetector, photocatalysis, optical display, optical sensing, and biomedical imaging, and so on. 展开更多
关键词 enhanced PHOTOLUMINESCENCE Cd Se NANO-WIRE COLLOIDAL SELF-ASSEMBLED method porous Al2O3 film
Preparation and luminescent properties of CaF2:Ln3+(Ln:Er, Er/Yb)/Nafion composite films
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作者 Limei Song Jianhua Gao +3 位作者 Minmin Liang Xiaojun Li Jiangtao Li Liuchang Wang 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第3期232-236,共5页
In this work, CaF2:Ln3+(Ln:Er,Er/Yb)/Nafion composite films were prepared using Nafion as modifications and matrices by dripping method. The composite films were characterized by Fourier transform infrared spectroscop... In this work, CaF2:Ln3+(Ln:Er,Er/Yb)/Nafion composite films were prepared using Nafion as modifications and matrices by dripping method. The composite films were characterized by Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction(XRD) and scanning electron microscopy(SEM). Composite films are transparent and CaF2:Ln3+(Ln:Er,Er/Yb) nanoparticles are well dispersed in Nafion films.The thicknesses of CaF2:Er3+/Nafion and CaF2:Er3+,Yb3+/Nafion composite film are about 77 and 73 μm,respectively. The nanoparticles in composite film possess cubic phase. CaF2:Er3+,Yb3+/Nafion composite film has stronger characteristic emission of Er3+ around 1530 nm with full width at half-maximum(FWHM) of 73 nm and longer luminescence lifetimes of 22.04 μs(25.03%) and 100.77 μs(74.97%). 展开更多
关键词 CAF2 nanoparticles Photoluminescence ERBIUM NAFION Composite film Rare earths
衬底钝化处理对CsPbBr3量子点薄膜发光稳定性影响 预览
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作者 赵海霞 王新伟 +5 位作者 李如雪 王登魁 方铉 房丹 魏志鹏 王晓华 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2019年第6期1706-1710,共5页
钙钛矿量子点因具有发光谱线窄、发光效率高、发光波长可调谐等优异的光学性能,在照明、显示、激光和太阳能电池等领域得到了广泛研究。然而,钙钛矿材料的稳定性问题,一直制约着其在光电器件中的应用。其中,钙钛矿材料在空气中受潮易分... 钙钛矿量子点因具有发光谱线窄、发光效率高、发光波长可调谐等优异的光学性能,在照明、显示、激光和太阳能电池等领域得到了广泛研究。然而,钙钛矿材料的稳定性问题,一直制约着其在光电器件中的应用。其中,钙钛矿材料在空气中受潮易分解的不稳定性尤为突出,这将严重影响其发光性质。为此,研究人员采用多种手段来改善钙钛矿材料的稳定性。目前,常见的方法是将一些具有疏水性的聚合物材料(例如POSS,PMMA等)引入到钙钛矿纳米晶中,或将钙钛矿纳米晶嵌入到介孔二氧化硅材料中,避免钙钛矿纳米晶暴露于空气中破坏其结构,以此来增强钙钛矿材料的发光稳定性。此外,钝化处理钙钛矿纳米晶表面,也是改善钙钛矿发光稳定性的一种常用方法。这些方法虽然在一定程度上可以改善钙钛矿的发光稳定性,但是在与有机物合成的过程中不免会引入其他有机官能团,介孔二氧化硅的引入,其处理方式相对复杂,而对钙钛矿纳米晶表面的钝化处理会破坏材料的原有结构。以上问题,都会影响钙钛矿的发光性质,不利于其在光电器件中的应用。硅(Si)具有低成本、大尺寸、高质量、导电好等优点,常被选作钙钛矿量子点光电器件的衬底材料。但是,由于Si衬底长时间暴露于空气,其表面易形成一层具有硅烷醇基团(Si—OH)的亲水性薄膜,这将对硅基钙钛矿器件的稳定性产生影响。因此,对Si表面进行钝化处理,破坏其表面Si—OH键,可以降低衬底表面的亲水性,增强疏水性,从而提高钙钛矿材料在器件中的稳定性。本研究使用氢氟酸(HF)对Si衬底表面进行钝化处理,发现钝化处理后的Si衬底表面与水的接触角由50.4°逐渐增大至87.7°,表明Si衬底表面由亲水性逐渐转变为疏水性。利用场致发射扫描电子显微镜(FE-SEM)测试发现,钝化处理后的Si衬底表面变粗糙,并且其表面上的CsPbBr 展开更多
关键词 钝化 衬底 CsPbBr3量子点 稳定性 光致发光
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贵金属纳米颗粒-二维过渡金属硫化物复合纳米结构:制备技术与光电性能综述 预览
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作者 吴治涌 水世显 +2 位作者 张显 杨鹏 万艳芬 《材料导报》 EI CAS CSCD 北大核心 2019年第3期426-432,共7页
过渡金属硫化物是由过渡金属元素和硫族元素构成,结构通式为MX 2,其中M和X分别代表过渡金属和硫族元素。与石墨烯类似,过渡金属硫化物也是二维层状材料,层内由共价键键合形成六角网状结构,层间由范德华力相互作用堆积而成。然而,纯的石... 过渡金属硫化物是由过渡金属元素和硫族元素构成,结构通式为MX 2,其中M和X分别代表过渡金属和硫族元素。与石墨烯类似,过渡金属硫化物也是二维层状材料,层内由共价键键合形成六角网状结构,层间由范德华力相互作用堆积而成。然而,纯的石墨烯的零带隙限制了其在大多数电子和光电子上的应用。相反,已有研究表明,MoS 2由块体材料厚度逐渐减小为单层材料时,其能带结构由间接带隙转变为直接带隙。同样,电子输运测试结果表明,二维过渡金属硫化物具有高的载流子迁移率、大的开关比等。但是二维过渡金属硫化物光吸收及光发射强度低,在很大程度上限制了该材料在光电领域的应用。为了突破二维过渡金属硫化物自身光吸收和光发射强度低的局限性,科研工作者将贵金属纳米颗粒独特的等离激元共振效应作为激发泵浦,增强二维过渡金属硫化物的光致发光效率,使贵金属纳米颗粒-二维过渡金属硫化物复合纳米结构展现出独特的光学性能和电学性能,为其在光学、生物、存储、电学以及催化等领域的应用开辟了新的道路。目前,对贵金属纳米颗粒-二维过渡金属硫化物复合纳米结构的研究,主要集中在利用贵金属纳米球、纳米棒、纳米岛、纳米盘、纳米天线、纳米核壳等结构对光进行汇聚,激发贵金属纳米结构中的表面等离激元,再将能量转移给二维过渡金属硫化物,进而在其中产生高强度的光吸收和光发射,对其光学特性产生明显的调制作用,并研究该复合纳米结构的光致发光和光生电流的增强特性。前期报道中主要采用电子束刻蚀、旋涂、浸润等方法来构筑复合纳米结构,但以上方法构筑的复合纳米结构中贵金属纳米颗粒沉积位置不可控,无序的纳米颗粒易在过渡金属硫化物的边缘和缺陷位置沉积,导致基面位置纳米颗粒厚度不均匀,这就在一定� 展开更多
关键词 贵金属纳米颗粒-二维过渡金属硫化物复合纳米结构 等离激元共振效应 光致发光 光生电流
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多面体共替代对Sr2(Al1–x Mgx)(Al1–x Si1+x)O7:Eu2+晶体结构和发光颜色的影响 预览
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作者 王庆玲 迪拉热·哈力木拉提 +1 位作者 沈玉玲 艾尔肯·斯地克 《物理学报》 SCIE EI CAS CSCD 北大核心 2019年第10期40-46,共7页
采用高温固相法合成Sr1.98(Al1–x Mgx)(Al1–x Si1+x)O7: 2%Eu2+荧光粉完全固溶体,利用X射线衍射、光致发光光谱和光学显微镜进行晶体结构和发光性能的研究. Sr2Al2SiO7和Sr2MgSi2O7同构化合物中包含[MgO4]、[SiO4]和[AlO4]四面体,较... 采用高温固相法合成Sr1.98(Al1–x Mgx)(Al1–x Si1+x)O7: 2%Eu2+荧光粉完全固溶体,利用X射线衍射、光致发光光谱和光学显微镜进行晶体结构和发光性能的研究. Sr2Al2SiO7和Sr2MgSi2O7同构化合物中包含[MgO4]、[SiO4]和[AlO4]四面体,较大体积的[MgO4]和较小体积的[SiO4],共同替代体积相似的[AlO4],导致[(Si/Al)O4]收缩和[(Mg/Al)O4]膨胀,晶胞参数c减少, a和V增大,使Eu2+周围的环境发生改变,晶体场劈裂程度减小,发射峰位从503 nm蓝移至467 nm,实现发光光谱从绿色(0.2384, 0.3919)到蓝色(0.1342,0.1673)的转变.当x为0时,发射峰的半高宽为120 nm, x从0.25增加到1时,半高宽由89 nm逐渐减小至50 nm,多面体的替代会改变荧光粉的发光性能. 展开更多
关键词 Sr2(Al1–x Mgx)(Al1–x Si1+x)O7 光致发光 共替代 配位多面体
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Ce掺杂ZnO的晶体结构、发光和光催化性能的不同机理 预览
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作者 王古平 彭萍萍 +1 位作者 赵森 俞鼎行 《化学工程师》 CAS 2019年第4期13-17,26共6页
采用溶胶凝胶法合成了一系列Ce掺杂ZnO粉晶。采用XRD,UV-VIS,FT-IR,PL技术及以亚甲基蓝溶液脱色反应为模型,研究了Ce掺杂ZnO晶体结构、光学带隙、成键、光致发光及光催化性能产生的不同机理。结果表明:低含量Ce掺杂和高含量Ce掺杂对ZnO... 采用溶胶凝胶法合成了一系列Ce掺杂ZnO粉晶。采用XRD,UV-VIS,FT-IR,PL技术及以亚甲基蓝溶液脱色反应为模型,研究了Ce掺杂ZnO晶体结构、光学带隙、成键、光致发光及光催化性能产生的不同机理。结果表明:低含量Ce掺杂和高含量Ce掺杂对ZnO结构和性能产生的机理存在差异。低含量Ce掺杂时,ZnO晶格参数及Zn-O键长因原子半径大的Ce^3+替代原子半径小的Zn2+而增加,光学带隙因Burstein-Moss效应而宽化,结晶性能因ZnO成核空间增加而提高,青蓝色发光峰因结晶性能提高而减弱。高含量Ce掺杂时,ZnO晶格参数及Zn-O键长因Ce^3+Ce^4+转化而减小,光学带隙因Ce^3+占据Zn^2+格位而减小,结晶性能因氧化铈包覆作用并降低结晶速率而提高,青蓝色发光峰随缺陷增加而增强。Ce掺杂ZnO光催化能力随光学带隙减小而提高。光催化性能最优Ce掺杂量为2%。FT-IR表明系列Ce掺杂ZnO均含有Zn-O和Ce-O-Zn等成键。 展开更多
关键词 铈掺杂 氧化锌 光致发光 光催化
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Stable single photon sources in the near C-band range above 400 K 预览
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作者 Qiang Li Ji-Yang Zhou +3 位作者 Zheng-Hao Liu Jin-Shi Xu Chuan-Feng Li Guang-Can Guo 《半导体学报:英文版》 EI CAS CSCD 2019年第7期80-84,共5页
The intrinsic characteristics of single photons became critical issues since the early development of quantum mechanics. Nowadays, acting as flying qubits, single photons are shown to play important roles in the quant... The intrinsic characteristics of single photons became critical issues since the early development of quantum mechanics. Nowadays, acting as flying qubits, single photons are shown to play important roles in the quantum key distribution and quantum networks. Many different single photon sources (SPSs) have been developed. Point defects in silicon carbide (SiC) have been shown to be promising SPS candidates in the telecom range. In this work, we demonstrate a stable SPS in an epitaxial 3CSiC with the wavelength in the near C-band range, which is very suitable for fiber communications. The observed SPSs show high single photon purity and stable fluorescence at even above 400 K. The lifetimes of the SPSs are found to be almost linearly decreased with the increase of temperature. Since the epitaxial 3C-SiC can be conveniently nanofabricated, these stable near Cband SPSs would find important applications in the integrated photonic devices. 展开更多
关键词 single PHOTON source STABLE PHOTOLUMINESCENCE silicon CARBIDE ELEVATED temperature
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