蓝色发光材料MGa2S4:Ce(M=Ca,Sr)发光特性的研究

制备了可用于蓝色ＴＦＥＬ的粉末发光材料ＭＧａ２Ｓ４：Ｇｅ（Ｍ＝Ｃａ，Ｓｒ）地其昌体结构进行了Ｘ射线分析，测量并其激光光谱和发射光谱，研究了Ｃｅ＾３＋浓度的变化对ＣａＧａ２Ｓ４：Ｃｅ和ＳｒＧａ２Ｓ４：Ｃｅ的激光光谱，发射光谱、色纯工及发光强度的影响，同时研究了基质组分的改变对发光特性的影响，结果表明，ＣａＧａ２Ｓ４：Ｃｅ和ＳｒＧａ２Ｓ４：Ｃｅ的可发射纯蓝色光，色纯度好，对ＣａＧａ２Ｓ４：Ｃｅ来说，实     

电致发光材料MGa2S4：Ce的合成及其发光特性

用固相反应法制备ＣａＳ，ＳｒＳ，ｇＡ２ＳＥ及Ｃｅ２Ｓ３，进而合成了ＭＧａ２Ｓ４：Ｃｅ（Ｍ＝Ｃａ，Ｓｒ）电致发光材料，ＣａＧａ２Ｓ４和ＳｒＧａ２Ｓ４同属Ｄ＾２４２ｈ空间群中斜方晶系结构。     

掺杂BaCeO3和SrCeO3在氧,氢及水气气氛下的电导性能

掺杂碱土金属铈酸盐系统：ＭＣｅ１－ｘＲｘＯ３－ｘ／２（Ｍ＝Ｂａ，Ｓｒ；Ｒ＝Ｙｂ，Ｙ，Ｇｄ，Ｌａ；ｘ＝０．０１～０．１０）可由固相反应制得单相化合物，Ｘ射线衍射分析表明，掺杂元素及掺杂量对掺杂ＢａＣｅＯ３和ＳｒＣｅＯ３的晶体结构影响不大。用复数阻抗谱研究了在氧、氢、水气气氛下的电导性能。在各种气氛下ＭＣｅ０．９５Ｙｂ０．０５Ｏ２．９７５（Ｍ＝Ｂａ，Ｓｒ）的电导率最大。根据测试结果，结合缺陷化学理论讨     

浸渍涂布法制备（CaxLa_l－x）FeO_3薄膜及其气敏效应的研究

利用含有Ｃａ，Ｌａ和Ｆｅ成分的水溶胶（摩尔比为Ｃａ：Ｌａ：Ｆｅ＝０．２５：０．７５：ｌ），经浸渍──提拉──干燥──焙烧过程分别在玻璃衬底及Ａｌ＿２Ｏ＿３基片上制备了薄膜。通过ＸＲＤ和ＸＰＳ分析表明玻璃衬底上的薄膜是成分准确的钙钛矿结构的（Ｃａ＿０．２５Ｌａ＿０．７５）ＦｅＯ＿３薄膜，而Ａｌ＿２Ｏ＿３基片上的薄膜是成分不确切且呈混合相的薄膜；借助ＳＥＭ观察了薄膜的表面微结构；测试Ａｌ２０３基片上的薄膜对酒精的气敏效应，发现在较低的工作温度下，薄膜对低浓度的酒精蒸气有高的灵敏度。     

一种制备r—Fe2O3薄膜的新方法

采用一种简单的新工艺分别在硅片和氧化铝陶瓷基片上制备了ｒ－Ｆｅ２Ｏ３薄膜。该工艺分３步完成：首先利用Ｆｅ（ＮＯ２）３酒精溶液通过浸渍涂布工艺制备ａ－Ｆｅ２Ｏ３薄膜，其次ａ－Ｆｅ２Ｏ３薄膜在氢气流中、３２０￣３５０℃之间热处理３０ｍｉｎ被还原为Ｆｅ３Ｏ４薄膜，最后Ｆｅ３Ｏ４薄膜在空气中２５０℃左右热处理３０ｍｉｎ被氧化为ｒ－Ｆｅ２Ｏ３薄膜。ＸＲＤ和ＳＥＭ分析结果表明该ｒ－Ｆｅ２Ｏ３薄膜呈尖晶石物相和     

蓝色SrS：Ce薄膜电致发光矩阵屏

采用ＳｒＳ：Ｃｅ作为发光层制备了可用于彩色薄膜电致发光显示的较大面积的蓝色薄膜电致发光显示屏。非矩阵屏在１ＫＨｚ驱动时最高亮度是９００ｃｄ／ｍ２；矩阵屏亮度为３０ｃｄ／ｍ２；矩阵面积为４０ｍｍ×７５ｍｍ，象元数为８０×１５０线，象元面积为０３ｍｍ×０３ｍｍ。ＳｒＳ：Ｃｅ蓝色发光粉是采用Ｈ２法还原ＳｒＳＯ４得到的。对不同的合成方法及结构，Ｃｅ３＋浓度对ＰＬ性能的影响等进行了较系统的分析。     

SI—GaAs中的EL2和EL6缺陷团簇相关性研究

用光致电流瞬态谱（ＰＩＴＳ）方法研究了ＬＥＣＳＩ－ＧａＡｓ原生单晶经常规退火和等时快速退火（ＲＴＡ）深能级缺陷的变化。缺陷ＥＬ２（Ｅｃ－０．８２ｅＶ）ＥＬ１２（Ｅｃ－０．７９ｅＶ）表现出类似的ＲＴＡ特性，应属于ＥＬ２缺陷团簇；缺陷ＥＬ６（Ｅｃ－０．３８ｅＶ），ＥＬ８（Ｅｃ－０．２７ｅＶ）和ＥＬ９（Ｅｃ－０．２４ｅＶ０亦具有相似的ＲＴＡ特性，属ＥＬ６缺陷团簇。实验发现，在热退火中，ＥＬ２团簇缺陷密度     

铁基巨磁阻抗薄膜的研究

溅射方法制备的非晶Ｆｅ６８Ｃｕ０．５Ｃｒ４Ｖ５Ｓｉ１３．５Ｂ９薄膜,通过适宜的退火处理得到具有纳米ａ－Ｆｅ（Ｓｉ）和非晶母相的混合结构和最佳的软磁性能,相应的巨磁阻抗值最高可达７２％。本着重研究了热处理条件、薄膜组织结构、较磁性能以及驱动电流频率对Ｆｅ６８Ｃｕ０．５Ｃｒ４Ｓｉ１３．５Ｂ９薄膜磁致阻抗的影响。     

SOCl_2/TiCl_4引发体系的α-蒎烯/苯乙烯阳离子共聚反应研究 Ⅰ.SOCl_2/TiCl_4的共聚合性能研究

通过对ＳＯＣｌ２／ＴｉＣｌ４引发体系的α－蒎烯（Ｍ１）／苯乙烯（Ｍ２）共聚产物进行ＧＰＣ、１ＨＮＭＲ以及微臭氧化－薄层层析法等分析表征，证明该引发体系能在宽广的单体投料比范围内实现有效共聚。在确认仅生成共聚物的反应条件下，采用Ｍａｙｏ－Ｌｅｗｉｓ式积分法测得该体系在－３０℃、［ＳＯＣｌ２］＝２０ｍｍｏｌ／Ｌ、［ＴｉＣｌ４］＝６０ｍｍｏｌ／Ｌ、ＣＨ２Ｃｌ２溶剂中的竞聚率分别为苯乙烯ｒ２＝２．３１±０．１５；α－蒎烯ｒ１＝０．５２±０．０６。     

RF等离子体CVD合成氮化碳薄膜的XPS研究

采用射频等离子体化学气相沉积技术合成氮化碳薄膜，测量其Ｘ射线光电子能谱（ＸＰＳ），获得两组Ｃ（１ｓ）电子和Ｎ（ｌｓ）电子结合能，它们是Ｅ（Ｃ＾１）＝３９８．０￣３９８．７ｅＶ，Ｅ（Ｃ＾２）＝２８４．６￣２８４．８ｅＶ；Ｅ（Ｎ＾１）＝３９８。０￣３９８．７ｅＶ，Ｅ（Ｎ＾２）＝４００．０￣４００．９ｅＶ。证实了薄膜中碳原子存在ｓｐ＾３杂化轨道成键和ｓｐ＾２杂化轨道成键两种键合形式。该方法合成的氮化碳薄     

蓝色发光材料MGa_2S_4:Ce(M=Ca,Sr)发光特性的研究

制备了可用于蓝色TFEL的粉末发光材料MGa2S4：Ce（M=Ca，Sr）并对其晶体结构进行了X射线分析，测量并研究了其激发光谱和发射光谱，研究了Ce3 浓度的变化对CaGa2S4：Ce和SrGa2S4：Ce的激发光谱.发射光谱、色纯度及发光强度的影响，同时研究了基质组份的改变对发光特性的影响．结果表明，CaGa2S4：Ce和SrGa2S4：Ce可发射纯蓝色光，色纯度好．对CaGa2S4：Ce来说，实现其高效率的、纯蓝色发射的最佳Ce3 浓度为6mol％，而SrGa2S4：Ce的最佳Ce3 浓度为3～4mol％．     

Effect of annealing temperature on growth of Ce-ZnO nanocomposite thin films: X-ray photoelectron spectroscopy study

Ce-doped ZnO nanocomposite thin films with Ce/Zn ratio fixed at optimum value (10 at.%) have been prepared via sol-gel method at different annealing temperatures varied from 180 to 500 °C. The synthesized samples were characterized employing atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) techniques. According to AFM analysis, the average grain size increased from about 70 nm to 150 nm by increasing the annealing temperature from 300 to 500 °C. Moreover, based on the XPS data analysis, it was found that three major metal ions namely Ce³⁺, Ce⁴⁺, and Zn²⁺ coexist on the surface of the nanocomposite films. XPS data analysis also revealed that Ce³⁺ ion is oxidized to Ce⁴⁺ ion with increasing annealing temperature. Due to oxidation, the ratio of [Ce^3±]/[Ce total] changed from 68.8 to 38.1% by increasing the annealing temperature from 180 to 500 °C. In addition, the Ce/Zn ratio increased from 0.21 to 0.42 when increasing the annealing temperature from 180 to 500 °C indicating migration of Ce ions toward the surface at higher temperatures. Finally, the XRD measurements determined that the ZnO thin films have a hexagonal wurtzite structure and CeO₂ crystallites are formed at 500 °C in the Ce-doped ZnO nanocomposite thin films.     

Optical properties of eu doped M-Ga2S4 (M: Zn, Ca, Sr) phosphors for white light emitting diodes

Eu2+ doped M-thiogallate (MGa2S4, M: Zn, Ca, Sr) phosphors were prepared by solid-state reaction. The dependence of luminescent properties, photoluminescence and cathodoluminescence, on M2+ ions was investigated. ZnGa2S4: Eu2+, CaGa2S4: Eu2+, and SrGa2S4: Eu2+ exhibited a green emission band at 540 nm, 560 nm, and 535 nm, respectively. The red-shift between CaGa2S4: Eu2+ and SrGa2S4: Eu2+ was originated from the radius difference of Ca2+ and Sr2+ ions. However, it did not apply to ZnGa2S4 : Eu2+ despite of smaller radius of Zn2+ ion. The particle size of ZnGa2S4 : Eu2+ was much smaller than those of the other thiogallates, leading to extremely low CL emission.     

实验优化设计中频反应溅射Al2O3:Ce薄膜发光性质研究

为了得到最优发光的薄膜材料成分参数,采用均匀设计和二次通用旋转组合设计相结合的方法建立发光强度与薄膜中氧含量和Ce³⁺ 离子掺杂浓度的回归方程,并用遗传算法求其取最大值时的解。用中频反应磁控溅射技术制备了相应成分的Al₂O₃:Ce非晶薄膜。在320nm光激发下,获得了较理想的发射光谱,对薄膜发光机理分析表明:薄膜的光致发光来自于Ce³⁺ 离子的5d1激发态向基态4f1的两个劈裂能级的跃迁。发光强度强烈的依赖于薄膜的掺杂浓度和氧元素含量。XPS检测表明,Al₂O₃:Ce薄膜中存在Ce³⁺ 。Ce³⁺ 含量和薄膜的化学成分是通过X射线散射能谱(EDS)测量的。薄膜试样的晶体结构应用X射线衍射分析。     

X-Ray absorption study of CeO2 and Ce/V mixed oxide thin films obtained by sol-gel deposition

CeO₂ and Ce/V mixed oxide thin films prepared by sol-gel deposition and annealed in an air or argon atmosphere have been studied by chronocoulometry and by XAFS (X-ray absorption fine structure). Multielectron photoexcitations (MPE), well known to pervade XAFS spectra of Ce making the analysis of structural parameters unreliable, are removed with the help of the atomic absorption background, determined on simple Ce compounds. Distinct MPE estimates for Ce³⁺ and Ce⁴⁺ ions are used. In the analysis of the recovered pure XAFS signal, the degree of disorder is found to depend on the Ce/V molar ratio and on the heating atmosphere. The disorder correlates with charge capacity of films, both increasing with vanadium content and V⁴⁺/V⁵⁺ molar ratio.     

Structural and optical properties of nanocrystalline CdSe and Al:CdSe thin films for photoelectrochemical application

Nanocrystalline CdSe and Al:CdSe semiconductor thin films have been successfully synthesized onto amorphous and FTO glass substrates by spray pyrolysis technique. Aqueous solutions containing precursors of Cd and Se have been used to obtain good quality films. The optimized films have been characterized for their structural, morphological, wettability and optical properties. X-ray diffraction (XRD) studies show that the films are polycrystalline in nature with hexagonal crystal structure. Scanning electron microscopy (SEM) studies show that the film surface is smooth, uniform and compact in nature. Water wettability study reveals that the films are hydrophilic behavior. The formation of CdSe and Al:CdSe thin film were confirmed with the help of FTIR spectroscopy. UV–vis spectrophotometric measurement showed a direct allowed band gap lying in the range 1.673–1.87 eV. Output characteristics were studied by using cell configuration n- CdSe/Al:CdSe |1 M (NaOH + Na₂ + S)|C. An efficient solar cell having a power conversion efficiency of 0.38% at illumination 25 mW cm⁻² was fabricated.     

Photoemission study of the tin doped cerium oxide thin films prepared by RF magnetron sputtering

Ce-Sn-O mixed oxide films prepared by simultaneous Sn metal and cerium oxide magnetron sputtering were studied by high resolution photoemission. The analysis showed that the degree of reduction of the cerium oxide depends on the tin concentration in the film. Ce⁴⁺ → Ce³⁺ conversion is explained by a charge transfer from Sn atoms to unoccupied orbital Ce 4f⁰ of cerium oxide by forming Ce 4f¹ state. The X-ray Photoelectron Spectroscopy data were compared with study of the single-crystalline CeO₂ thin films and Sn/CeO₂(111) model system prepared and studied in situ excluding air exposure effects.     

Ce掺杂对TbFeCo材料磁光性能影响的研究

采用射频磁控溅射方法制备了TbFeCo非晶磁光薄膜，并在TbFeCo中引入轻稀土元素Ce，测试了薄膜的磁光性能。研究了薄膜成分对其磁光性能的影响。结果表明；在TbFeCo薄膜中掺入少量Ce时，薄膜的磁光克尔角及矫顽力都有所提高，矩形度也增加了。但随Ce掺入量的增加，薄膜的磁光性能发生恶化，较好的掺杂在10.31?左右。     

Properties of Ce-doped ITO films deposited on polymer substrate by DC magnetron sputtering

Ce-doped indium tin oxide (ITO:Ce) films were deposited on flexible polyimide substrates by DC magnetron sputtering using ITO targets containing various CeO₂ contents (CeO₂ : 0, 0.5, 3.0, 4.0, 6.0 wt.%) at room temperature and post-annealed at 200 °C. The crystallinity of the ITO films decreased with increasing Ce content, and it led to a decrease in surface roughness. In addition, a relatively small change in resistance in dynamic stress mode was obtained for ITO:Ce films even after the annealing at high temperature (200 °C). The minimum resistivity of the amorphous ITO:Ce films was 3.96 × 10^− 4 Ωcm, which was deposited using a 3.0 wt.% CeO₂ doped ITO target. The amorphous ITO:Ce films not only have comparable electrical properties to the polycrystalline films but also have a crystallization temperature > 200 °C. In addition, the amorphous ITO:Ce film showed stable mechanical properties in the bended state.