半导体制冷器的进展

半导体制冷器具有微型化、轻量化、无振动、长寿命等许多重要优点。目前３００Ｋ室温下优值系数Ｚ最高的半导体制冷材料是Ｐ型Ａｇ０．５８ＣＵ０．２９Ｔｉ０．９４Ｔｅ四元合金,２００－３００Ｋ普冷范围内三元Ｂｉ２Ｔｅ３－Ｓｂ２Ｔｅ３－Ｓｂ２Ｓｅ３固溶体合仍然应用最广且性能优良,而２０－２００Ｋ低温下则是Ｂｉ－Ｓｂ合金热电性能最好,电臂材料是决定半导体制冷器性能的主要因素,但通过改进电臂结构,设计特殊的电臂联     

A reliable guideline to maximize the detection and analysis of deep level defects: Comparison between DLTS analysis techniques

In this paper, we present reliable guidelines allowing to maximize the detection and analysis of deep defects in semiconductors by introducing a new method of analysis that we named Modified Levenberg-Marquardt Deep-Level Transient Spectroscopy (MLM-DLTS) based on the Levenberg-Marquardt algorithm that we modified deliberately and associated with two other high-resolution techniques, i.e. the Matrix Pencil algorithm and modified Prony's method. The performances of the method were first assessed with a procedure of simulation by generating multi-exponential capacitance transients with a changing signal-to-noise ratio. These different tests have demonstrated to what extent such a method of analysis is more efficient than classic correlation methods based on DLTS spectra and than three high-resolution methods already existing in the literature. Finally, when the signal-to-noise ratio is low, and in the aim of getting precise results, a few smoothing algorithms were tested. Our findings evidence how the smoothing quality can be controlled under certain conditions while avoiding both the distortions in the shape of the capacitance transients and the DLTS spectra.     

行波管收集极的辐射散热研究

本文从节约卫星重量的角度出发证明了空间行波管采用辐射冷却收集极的优越性,并且通过对收集极的稳态热分析为获得收集极内部温度和热应力的分布提供了一种途径。     

(CdSe)1/(ZnSe)1应力半导体材料缺陷能级

用实空间 Recursion方法计算 (Cd Se) 1 / (Zn Se) 1 应力半导体材料的总态密度、局域态密度、分波态密度 ,研究了局域特性和缺陷能级 ,得出了一些有价值的结论。     

碲化镉和碲镉锌的深低温光致发光研究

本文报道了用热壁熔体法,布里奇曼法等多种工艺技术制备的 CdTe、Cd_xZn_(1-x)Te单晶体材料和薄膜材料在1.8K深低温下光致发光的测量结果.从光致发光谱中识别出(D~°,X)、(D~+,X)、(A~°,X)、DAP等一系列谱线.逐个分析了它们的物理起源,并由此进一步讨论了晶体中的残留杂质、缺陷、结构完整性、组份均匀性等与材料质量有关的问题.     

关于微光像增强器的品质因数

20世纪60年代以来,微光夜视像增强器的技术进步一直是以“代”来评价的。通常理解是一代比一代优越。20世纪,在微光夜视像增强器发展的过程中,相继出现60年代的纤维光学面板级联耦合的像增强器(第一代),70年代的微通道板像增强器(第二代)和80年代的GaAs负电子亲和势光阴极像增强器(第三代)。从事夜视技术的科学家们一直在探索新一代或第四代像增强器技术。什么是第四代,在夜视学术界是有争论的。问题在于,像增强器以代来划分,以代来评价,是否合适和全面;评价像增强器的优劣是性能还是技术;以什么表示像增强器的性能更好和更全面;这些问题引起了夜视学术界的深思。文中阐述了微光像增强器总体性能应以品质因数而不是代的概念进行评价。     

Properties of fluorine-doped SnO2 thin films by a green sol–gel method

Fluorine doped tin oxide (FTO) films were fabricated on a glass substrate by a green sol–gel dip-coating process. Non-toxic SnF₂ was used as fluorine source to replace toxic HF or NH₄F. Effect of SnF₂ content, 0–10 mol%, on structure, electrical resistivity, and optical transmittance of the films were investigated using X-ray diffraction, Hall effect measurements, and UV–vis spectra. Structural analysis revealed that the films are polycrystalline with a tetragonal crystal structure. Grain size varies from 43 to 21 nm with increasing fluorine concentration, which in fact critically impacts resultant electrical and optical properties. The 500 °C-annealed FTO film containing 6 mol% SnF₂ shows the lowest electrical resistivity 7.0×10⁻⁴ Ω cm, carrier concentration 1.1×10²¹ cm⁻³, Hall mobility 8.1 cm²V⁻¹ s⁻¹, optical transmittance 90.1% and optical band-gap 3.91 eV. The 6 mol% SnF₂ added film has the highest figure of merit 2.43×10⁻² Ω⁻¹ which is four times higher than that of un-doped FTO films. Because of the promising electrical and optical properties, F-doped thin films prepared by this green process are well-suited for use in all aspects of transparent conducting oxide.     

关于超大规模集成电路制造中的应力迁移问题

应力迁移是影响集成电路（ＩＣ）金属配线可靠性的缺陷之一。它缘起于绝缘膜与金属配线之间的热应力。本文概要介绍两种性质的绝缘膜产生的两种应力缺陷以及检测方式,并分类说明金属膜厚、线宽温度等与应力的关系。简要说明应力迁移产生的可能机理及目前采取的几种对策。     

空气中自导光丝超连续辐射后向散射增强特性

由自导成丝效应产生的超连续辐射具有超宽带光谱、后向散射增强等一系列新特征,为激光雷达大气探测开辟了新的领域.通过测量飞秒激光脉冲自导光丝超连续辐射散射的角度分布,对不同条件空气中自导光丝产生的超连续辐射后向散射特性进行了实验研究.结果表明,在洁净空气和含气溶胶的空气中,自导光丝的超连续辐射都呈现出明显的后向散射增强特性.同时对超连续辐射后向散射的测量值进行拟合,拟合结果表明超连续辐射后向散射角分布满足洛伦兹(Lorentz)函数,在洁净空气中其角宽度为6.4°,后向180°时归一化散射强度是瑞利散射的3.2倍.超连续辐射沿光丝前向呈锥形辐射,其前向散射具有明显的波长依赖关系;而后向散射无明显的波长依赖关系.     

生长材料中掺杂杂质纵向分布的扩散生长理论

从ＭＯＣＶＤ和卤化物ＶＰＥ的生长装置出发，分析了量子阱激光材料和微波电子材料中引入杂质的纵向分布和谐过程。采用了掺入杂质分子经载体气体漂移扩散输运和生长过程中再扩散的数学物理理论，导出了掺杂杂质最终纵向浓度分布的数学定量解析式。根据本理论，提出了陡峭掺杂和均匀纵向浓度分布的工艺解决方案。     

三维非均匀散射层与其中异常目标的辐射传输

讨论了三维非均匀散射层与其中有异常目标的矢量辐射传输高阶散射与辐射的求解与数值模拟.将三维非均匀散射介质在垂直方位z轴方向划分成许多薄层,再在水平(x,y)方位上划分成方格,用分割形成的各薄盒的零阶热辐射和一阶Mueller矩阵解,推导多阶辐射传输的迭代方法,获得整个散射介质三维VRT方程的高阶散射与辐射解.模拟了微波频段在各空间分辨率的辐射计观测下非均匀植被层和地面上有异常目标的极化辐射亮度温度的观测图像.     

厚金属板与台阶的散射

将每种极化的照射分解为对称与反对称照射之和,丛而将厚金属板的散射问题化为两种台阶的散射问题。用Wiener-Hopf法求得散射场的Fourier变换后,从中减去表面均匀电流的辐射场的Fourier变换,应用鞍点法即可求得棱边的散射场。根据线电流与电偶极辐射场的关系,由无限长棱边的场反推得微元的场。此结果可用于曲率不大的有限长曲棱边。     

Synthesis and Thermoelectric Properties of the Double-Filled Skutterudite Yb<Subscript>0.2</Subscript>In<Subscript><Emphasis Type="Italic">y</Emphasis></Subscript>Co<Subscript>4</Subscript>Sb<Subscript>12</Subscript>

Filled skutterudites have long been singled out as one of the prime examples of phonon glass electron crystal materials. Recently the double-filling approach in these materials has been attracting increased attention. In this study, Yb_0.2In _y Co₄Sb₁₂ (y = 0.0 to 0.2) samples have been prepared by a simple melting method and their thermoelectric properties have been investigated. The power factor is increased dramatically when increasing the In content, while the lattice thermal conductivity is lowered considerably, leading to a large increase of the ZT value. A state-of-the-art ZT value of 1.0 is attained in Yb_0.2In_0.2Co₄Sb₁₂ at 750 K.