ZnTeMOCVD过程中金属有机源双甲基锌和双异丁基碲热裂…

利用与ＭＯＣＶＤ系统相连接的四极质谱仪实时研究了金属有机源Ｍｅ２Ｚｎ和Ｐｒ＾ｉ２Ｔｅ城反应器中热裂解行为。报告了纯态Ｍｅ２Ｚｎ和Ｐｒ＾ｉ２Ｔｅ及其混合物Ｈ２和Ｈｅ气氛中的热裂解实验结果，并进行了分析讨论，导出了可能发生的气相反应及热裂解机理。     

Zn1—xMnx／ZnSe应变超晶格分子束外延生长及光学特性研究

用分子束外延方法在ＧａＡｓ（１００）衬底上成功生长了高质量的Ｚｎ１－ｘＭｎｘＳｅ／ＺｎＳｅ（ｘ＝０．１６），超晶格结构，用Ｘ射线衍射和低温光致发光（ＰＬ）对其结构，应变分布以及光学性能进行了研究，结果表明，２Ｋ温度下，Ｚｎ１－ｘＭｎｘＳｅ／ＺｎＳｅ超晶格的光致发光中主发光峰对应于ＺｎＳｅ阱中基态电子和基态轻空穴之间的自由激子跃迁，而且其峰位相对于ＺｎＳｅ薄膜材料的自由激子峰有明显移动。其中，当超晶     

高功率横流CO2激光器高反膜耦合窗口ZnSe热形变理论和实验研究

给出高功率横流ＣＯ２激光器高反膜红外膜红外耦合窗口ＺｎＳｅ的热形变理论和实验。在合理近似条件下，导出ＺｎＳｅ窗口温度分布和热形变的理论表达式。理论和实验相符。     

ZnSe－ZnTe多量子阱室温下的反射型皮秒激子光双稳

本文首次研究了ＺｎＳｅ－ＺｎＴｅ多量子阱在室温下的反射型皮秒激子光双稳，实验结果表明，ＺｎＳｅ－ＺｎＴｅ多量子阱在室温下的反射型皮秒光双稳的阈值光强和对比度分别为１．１ＭＷ／ｃｍ２和６：１．根据测量得到的ＺｎＳｅ－ＺｎＴｅ多量子阱在室温下的激子吸收光谱及激子的非线性吸收理论，归结ＺｎＳｅ－ＺｎＴｅ多量子阱室温下的皮秒光双稳的主要非线性机理为ＺｎＳｅ－ＺｎＴｅ多量子阱的激子饱和吸收引起的折射率变化．     

Ⅱ—Ⅵ族稀磁半导体ZnSe／Zn1—xMnxSe超晶格中的应力效应

本文通过Ⅱ－Ⅵ族稀磁半导体超晶格ＺｎＳｅ／Ｚｎ１－ｘＭｎｘＳｅ的光致发光谱的测量，对其应力效应进行了讨论。样品的组分ｘ＝０．２，０．３，０．４，测量温度为Ｔ＝１１￣３００Ｋ。结果表明：由于应力效应，ＺｎＳｅ／Ｚｎ１－ｘＭｎｘＳｅ超晶格中的激子能量随ｘ值增加而发生红移。在相同组分下，不同阱、垒宽度比使应力的分布产生明显变化，从而影响超晶格中激子能量。实验与理论计算结果相一致。超晶格中光致发光峰随温度     

Zn_（1－x）Mg_xS_ySe_（1－y）四元半导体合金的拉曼散射光谱研究

用分子束外延方法在ＧａＡｓ（１００）衬底上生长了Ｚｎ１－ｘＭｇｘＳｙＳｅ１－ｙ四元半导体合金薄膜．用Ｘ－射线衍射方法确定了外延层的结构和晶格常数．测量了这些样品在平行和垂直两种不同几何配置下的拉曼散射光谱并对其特性做了研究。从实验上观察到了四类不同的晶格振动模：类ＺｎＳｅ的ＴＯ和ＬＯ模以及类ＺｎＳ和类ＭｇＳ的ＬＯ模，实验发现：在ＺｎＳｅ和ＺｎＳＳｅ中加入Ｍｇ使得类ＺｎＳｅ的ＴＯ和ＬＯ模的振动频率下降；同时，也使类ＺｎＳ模的频率随Ｓ的增加率减小。     

GeSb_2Te_4相变光存储薄膜材料的短波长静态记录特性的研究

研究了单层ＧｅＳｂ２Ｔｅ４真空射频溅射薄膜在４００ｎｍ～８３０ｎｍ区域的吸收、反射光谱和光学常数（ｎ，ｋ），发现ＧｅＳｂ２Ｔｅ４薄膜在４００ｎｍ～６００ｎｍ波长范围内具有较强的吸收。在短波长静态测试仪上测试了ＧｅＳｂ２Ｔｅ４薄膜的光存储记录特性，发现在５１４．５ｎｍ波长用较低功率的激光辐照样品时薄膜在写入前后的反射率变化较大，擦除前后的反射率对比度较低，可通过膜层设计来提高     

火焰原子吸收微量进样法测定耳血中Cu,Zn,Ca,Mg和Fe

本文利用原子吸收分光光度法采用微量注射进样，测定耳全血中Ｃｕ，Ｚｎ，Ｃａ，Ｍｇ和Ｆｅ的含量，结果表明，方法回收率在９６％以上，样品测定的相对标准误差Ｚｎ，Ｃａ，Ｍｇ和Ｆｅ小于２％，Ｃｕ为３．９％，本方法快速，准确，仅需１０μＬ耳血即可获得五种生命元素含量的满意结果。     

GeSg2Te4相变光存储薄膜材料的短波长静态记录特性的研究

研究了单层ＧｅＳｂ２Ｔｅ４真空射频溅射薄膜在４００ｎｍ－８３０ｎｍ区域的吸收，反射光谱和光学常数，发现ＧｅＳｂ２Ｔｅ４薄膜在４００ｎｍ－６００ｎｍ波长范围内具有较强的吸收。在短波长静态测试仪上测试了ＧｅＳｂ２Ｔｅ４薄膜的光存储记录特性，发现在５１４．５ｎｍ波长用较低功率的激光辐照样品时薄膜在写入前后的反射率变化较大，擦除前后的发射率对比度较低，可通过膜层设计来提高。     

气固界面氧化学吸附物种的动态研究

用自编的傅里叶变换红外（ＦＴ－ＩＲ）动态谱批处理程序，在２０－６５０℃对Ｂｅ，Ｍｇ，Ｃａ，Ｌａ，Ｃｅ，Ｓｍ，Ｔｉ，Ｚｒ，Ｖ，Ｎｂ，ｃＲ，Ｍｏ，Ｗ，ＭＮ，Ｆｅ，Ｎｉ，Ｃｕ，Ｚｎ和Ｓｎ等一系列金属氧化物上的氧化学吸附物种进行了原位动态三维谱学研究，就所观测到的超氧（Ｏ＾－２）和过氧（Ｏ＾２－２）物种随温度的变化情况以及甲烷氧化偶联催化反应中的活性氧物种进行了讨论。     

MOCVD技术制备的ZnS:Mn电致发光薄膜结晶性及Mn2+分布

本文报导了用MOCVD技术制备的ZnS:Mn电致发光薄膜为立方晶相,结晶取向性好,颗粒大。从高倍率的扫描电镜拍摄的照片观察到薄膜的表面平滑。SIMS测量表明Mn2+在ZnS薄膜纵向分布均匀,但在两侧有起伏,可能的原因是在生长的初终阶段流量的突变使化合物的化学计量比偏离而产生位错,引起原子的局部堆积,并且由于初终阶段ZnS:Mn生长的衬底不同使原子堆积层厚度不同。     

Valence instability of Pr impurities in ZrIr2 and ZrOs2

This paper describes a search for valence instabilities of Pr impurities in ZrMe₂ with Me=Os, Ir and Ru. Pr impurities go into solution in the 2% concentration range in ZrIr₂ and ZrOs₂ but not in ZrRu₂. Susceptibility measurements indicate a nonmagnetic groundstate of Pr in both ZrIr₂ and ZrOs₂. The effective moment in ZrIr₂ is slightly below the trivalent value in ZrIr₂ while in ZrOs₂ the susceptibility is far below the trivalent value between helium and room temperatures. The resistivity increments of the alloys are very large and show very unusual temperature dependence, even for stable rare-earth (RE) impurities in ZrIr₂, where one observes strong deviations from the Matthiessen's rule at low temperatures. The depression of the superconducting transition temperature of ZrIr₂ and ZrOs₂ by Pr impurities is about 0.5 K/at%.     

Cd1-xZnxTe晶体退火条件的选择及Zn压对退火晶体质量的影响

采用传统Bridgman方法和加入accelerated crucible rotation technique的Bridgman(缩写为ACRT-B)方法生长的Cd_1-xZn_xTe(x=0.04)晶体中存在有点缺陷、位错、杂质和Te沉淀等缺陷.为了减少甚至消除这些缺陷,必须将生长后的CdZnTe晶片在Cd气氛下退火.从Cd-Te和Cd_0.96Zn_0.04Te的PT相图出发,详细讨论了CdZnTe晶体的气固平衡条件,并 关键词： 1-xZn_xTe')" href="#">Cd_1-xZn_xTe 退火 气-固平衡     

ZnTe/GaSb结构的X射线三轴晶散射和晶体截断杆研究

用X射线三轴晶散射和晶体截断杆扫描研究了不同工艺条件下分子束外延生长的ZnTe/GaSb结构．X射线晶体截断扫描显示，从衬底表面清洁温度到生长温度退火过程中采用Zn气氛的样品具有清晰的干涉条纹，而在Te气氛下退火则晶体截断扫描没有干涉条纹．在倒易点004，115附近X射线散射的二维强度分布图显示，两种条件下生长样品的晶格失配应力都没有弛豫．二维等强度分布图和沿［110］方向的扫描，都显示在Te气氛下生长的膜具有较强的漫散射，并且分布较宽．这种漫散射来源于界面相Ga₂Te_{3< 关键词：}     

Substituent effects on the reduction of 2–alkylcyclohexanones by LiAlH4: an investigation of conformational equilibria and transition states

Transition state (TS) structures for the reduction of 2‐Me and 2‐i‐Pr‐cyclohexanone by LiAlH₄ were optimized by density functional theory (B3LYP/6‐31G(d,p)). Four TS structures corresponding to axial and equatorial attacks by LiAlH₄ were located for each ketone conformer. Electronic potential maps were used to investigate the substituent electronic effect on the TS stabilization. The uneven carbonyl orbital distribution in the LUMO (π*) was also analyzed. Reduction stereoselectivity was shown to depend on both the ketone conformational ratio and on the reaction TS. Copyright © 2010 John Wiley & Sons, Ltd.     

ZnCdTe-ZnTe多量子阱的电场效应

本文报导了电场作用下ZnCdTe-ZnTe多量子阱的激子发光特性.用激子局域化的观点解释了激子发光峰随电场增强而增强的现象.在Zn0.8Cd0.2Te-ZnTe多量子阱中观察到了电场作用下自由激子发光谱峰较大的红移和较快的发光淬灭     

MOCVD modification of the surface of multiwalled carbon nanotubes to impart to them necessary physicochemical properties

Multiwalled iron-containing carbon nanotubes were synthesized by the MOCVD method with pyrolysis of ferrocene and toluene mixtures in an argon flow at atmospheric pressure. Using the MOCVD method with vacuum pyrolysis of bis-arene-chromium compounds onto the surface of multiwalled carbon nanotubes (MWCNTs), pyrolytic chromium films were deposited and new composite materials MWCNT/pyrolytic chromium were obtained. The composite morphology depends on the conditions of pyrolytic chromium deposition. Regular bead-shaped structures were detected. The mechanism of their appearance due to the formation of bis-arene chromium compounds of the intermediate viscoplastic polymer phase and the onset of Plateau-Rayleigh instability during pyrolysis is discussed.     

Ab initio study of II-(VI)2 dichalcogenides

The structural stabilities of the (Zn,Cd)(S,Se,Te)(2) dichalcogenides have been determined ab initio. These compounds are shown to be stable in the pyrite phase, in agreement with available experiments. Structural parameters for the ZnTe(2) pyrite semiconductor compound proposed here are presented. The opto-electronic properties of these dichalcogenide compounds have been calculated using quasiparticle GW theory. Bandgaps, band structures and effective masses are proposed as well as absorption coefficients and refraction indices. The compounds are all indirect semiconductors with very flat conduction band dispersion and high absorption coefficients. The work functions and surface properties are predicted. The Te and Se based compounds could be of interest as absorber materials in photovoltaic applications.     

GaP(N,Te,Zn)的静压光致荧光研究

对GaP(N,Te,Zn)样品做了77K的静压光致荧光研究。得到了N,NN₁,NN₃束缚激子能级的压力系数,以及施主Te和中性施主Te的束缚激子能级的压力系数。讨论了这些能级随压力的变化行为,并首次观察到Gap中自由激子的零声子发射。 关键词：     

Electrical properties of HgCdTe films grown by MOCVD and doped with as

Electrical properties of HgCdTe films grown by metal-organic chemical vapour deposition (MOCVD) on GaAs substrates and doped with the As acceptor during the growth were studied. Discrete mobility spectrum analysis was used to extract the parameters of the as-grown films and films after ion milling and during prolonged relaxation of milling-induced defects. The measurements revealed significant compensation of the as-grown MOCVD HgCdTe with As on Te sites being the main defect, residual donor concentration of the order of (2–5)×10¹⁵ cm^?3, and the presence of some unidentified defects.