闪耀光栅外腔反馈压窄半导体激光器线宽技术的研究

在讨论半导体激光线宽压窄理论的基础上,利用闪耀光栅作为外部反馈元件,介绍了由中心波长为949.6nm、原始线宽为1.2THz的单管半导体激光器构成的反馈外腔,它能够很好的改善半导体激光器的性能。实验得到了中心波长稳定的、单纵模的高质量激光输出,边模抑制比大于30dB,线宽优于1.2MHz(Δλ<3.6×10-6nm)。实验证实了强反馈能够很好地改善外腔半导体激光器的动态特性。     

The electrical properties of semiconductor/metal,semiconductor/liquid,and semiconductor/conducting polymer contacts

Critical comparisons are drawn between the basic electrical properties of semiconductor/metal, semiconductor/liquid, and semiconductor/conducting polymer junctions. A theoretical model is developed to describe the basic current-voltage properties of semiconductor contacts, with emphasis on the contrasts between ideal and observed behavior. Using the concepts from this model, the characteristics of a variety of semiconductor contacts are evaluated. The discussion focuses on the following semiconductors: Si, GaAs, InP, and II-VI compounds based on the Cd-(chalcogenide) materials.     

半导体冰箱热管及变工况控制的研究

详细阐述了分离式热管散热方式和变工况控制半导体制冷片运行参数在半导体冰箱中的应用,并对分离式重力热管散热、半导体冰箱变工况控制与冰箱的制作进行了探讨。实验表明:该冰箱的制冷效率有了较大的提高,实现了整机的高效节能效果。     

半导体玻璃微通道板的研制

介绍了半导体玻璃微通道板的主要性能，并与传统铅硅酸盐玻璃的相关性能进行了比较。阐述了半导体玻璃的研制工艺，研究了利用半导体玻璃材料制备微通道板的工艺途径，开发了靠玻璃本身体电导性质而无需氢还原工艺的微通道板，即半导体玻璃微通道板。研制出孔径为20μm、外径为12mm的半导体玻璃微通道板，实验利用紫外光电法测试了微通道板的增益、闪烁噪声和成像性能。结果表明新型微通道板具有明显的电子增益和低的闪烁噪声，并且通道表面稳定；利用磷硅酸盐玻璃材料可以实现体导电微通道板的制备。     

大功率半导体激光器发展及相关技术概述

激光被称为"最快的刀"、"最准的尺"、"最亮的光",与原子能、计算机、半导体并称为20世纪新四大发明。大功率半导体激光器在工业加工、医疗美容、光纤通信、无人驾驶、智能机器人等方面有着广泛的应用。如何实现大功率半导体激光光源,一直以来都是国际的研究前沿和学科热点。为此,简述了大功率半导体激光器的发展历史,综述了大功率半导体激光器的共用技术,包括大功率芯片技术和大功率合束技术,并对大功率半导体激光的发展方向进行了展望。     

用光声技术研究半导体TiO2,ZnO纳米晶粉的光学特性

应用新型的光声光谱技术,研究了不同种类和不同制备工艺条件的半导体纳米晶粉的光学特性,测量了半导体TiO2、ZnO和掺铝ZnO纳米晶粉的光声光谱,获得了这些半导体纳米晶粉的带隙和光谱吸收系数.研究结果表明,相同种类和相同颗粒形状的半导体纳米晶粉的粒径越小,光学吸收系数越大.半导体纳米晶粉的带隙与相同种类纳米颗粒形状(圆球...     

半导体可饱和吸收镜作为被动锁模吸收体实现超短脉冲可见激光发展状况

介绍了当前国际上流行的一种用于固体激光器被动锁模以获得皮秒和飞秒宽度脉冲的新型半导体吸收体 半导体可饱和吸收镜的基本原理和制作方法。描述了利用半导体可饱和吸收镜和倍频晶体获得可见光超短脉冲激光方面的研究现状,指出半导体可饱和吸收镜的使用将会加速超短脉冲三基色激光器的研制进程。     

Ultrafast laser spectroscopy of semiconductor nanocrystals

A large amount of work has been worldwide directed to understand the properties of semiconductor nanostructures. Ultrafast lasers with pulsewidths of a few femtoseconds allowed the investigation of the dynamics of elementary excitations in semiconductor structures on ultrashort time scales. Recent progress in technology made it possible to fabricate semiconductor nanocrystals (i.e. crystals of nanometer dimensions) of well-defined properties. The purpose of this paper is to review the understanding of carrier relaxation and recombination processes in semiconductor nanocrystals as studied by ultrafast laser spectroscopy. The up-to-date techniques of ultrafast laser spectroscopy as well as the fabrication of semiconductor nanocrystals are discussed in some detail.     

不同形状的光斑触发砷化镓光导开关

为研究使用不同形状光斑触发光导开关对光电导特性的影响,研制了12 mm间隙的半绝缘砷化镓光导开关,在不同的偏置电压下,使用波长为1 064 nm的不同能量的激光触发光导开关并进行了光电导测试。使用了不同形状的光斑(包括面状、线状和点状光斑)触发光导开关并进行了光电导特性的比较,讨论了触发光参数对光导开关特性的影响。对处于开关电极间不同位置的线状光斑触发特性进行了比较,结果显示,本征光电导和非本征光电导情况下光斑位置对光电流的影响正好相反。     

瞬态光电流对有机薄膜光伏器件中肖特基接触的研究

制备了结构为氧化铟锡(ITO)/有机半导体/金属的有机薄膜光伏器件,电流--电压曲线显示其具有整流特性但有机半导体和电极间肖特基接触的内建电场方向很难判定.为了研究有机半导体和电极的肖特基接触特性,分别制备了结构为ITO/有机绝缘层/有机半导体/金属和ITO/有机半导体/有机绝缘层/金属的器件,通过调制激光照射下器件的瞬态光电流方向可容易判断有机半导体和电极间肖特基接触的内建电场方向,外加偏压下瞬态光电流的强度变化进一步证实了判断的正确性.     

表面结构对SnO2半导体纳米粒子荧光性质的影响

本文利用荧光光谱对ＳｎＯ２纳米粒子水溶胶及其有机溶胶的光学性质进行了研究。发现粒子的表面结构对其光学性质具有极大的影响。水溶胶的荧光发射是由氧空位控制的,其发射强度工;有机溶胶由于表面活性剂的作用,改变粒子的表面结构,得到较强的荧光发射。     

Fully analytical evaluation of optical gain coefficient in bulk semiconductors in quasi-equilibrium free-carrier approximation

In this letter, a new analytical method is presented to calculate of the semiconductor optical gain coefficient. This method is particularly suitable for theoretical analyses to determine the dependence of semiconductor gain on the total carrier density and temperature in the semiconductor lasers. Also, the optical gain functions for semiconductor optical gain coefficient are presented analytically. The analytical evaluation is verified with numerical methods, which illustrates the accuracy of these obtained analytical expressions.     

激光测距用半导体脉冲激光测头的研究

研究了激光测距用半导体脉冲激光测头。通过对基于脉冲激光测距原理的半导体脉冲激光器的参数测量分析,研究了半导体脉冲激光的发射和接收。通过优化光学镜头组合,对半导体激光分散光束进行了平行准直。通过开发脉冲激光驱动电路、光电探测接收放大电路和半导体脉冲激光测距实验装置,研制了满足中距离激光测距要求的半导体脉冲激光测头。     

Laser induced superconducting properties in semiconductors

We show that an amorphous semiconductor irradiated by a laser light exhibits a sort of the Meissner effect. A guided light in a thin film of an amorphous semiconductor is stopped or modified in its intensity when the semiconductor is illuminated by another light.     

半导体激光器光波准直特性研究

分析了半导体激光器光波经准直透镜的传输特性,对影响准直光束质量的主要因素作了深入讨论,并在实验上利用小口径大数值孔径透镜获得了高准确直度的光束。     

半导体制冷及其在物理实验中的应用

半导体制冷是通过空穴和电子在运动中直接传递热量的固体致冷方式.本文通过半导体致冷型恒温量热器和半导体热电特性实验为例,说明在物理实验中应用半导体制冷技术的设计思路及优势.     

Intrinsic ferromagnetism created by vacancy injection in a semiconductor oxide Ti<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Co<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>O<Subscript>2 − δ</Subscript>

The possibility of creating room-temperature intrinsic ferromagnetism in a highly doped oxide semiconductor has been investigated. The results indicate that such state of a ferromagnetic semiconductor can be achieved by magnetron sputtering deposition of a semiconductor oxide doped with a transition metal followed by low-temperature vacuum annealing.     

Emergence of the half-metallic performance in transition-metal doped BAs semiconductor: a first-principles study

ABSTRACT

A spin density functional study of structural, electronic and magnetic properties of BAs semiconductor doped with different transition metals is reported. Cr is favourable to dope in BAs semiconductor. Transition metal dopants increase the lattice parameters and their volumes. The net magnetisation is mainly donated from transition metal, As and B, respectively. The computations remark that the transition metals introduce the d orbitals inside host band gap. The magnetism is formed by the hybridisation between d orbitals of transition metal and p orbitals of As, called p-d hybridisation. Fe and Cu doping in BAs semiconductor become metallic. The semiconductor to dilute magnetic semiconductor transformation by doping with Cr, Mn and Co is important for exploring the possibilities of the spintronic applications. Finally, this research offers the innovative perception into the nature of transition metals doping in BAs semiconductor at a quantitative level and envisages a new spintronic materials.     

Hydrogen at semiconductor grain boundaries and interfaces

This paper is a review of the known effects of hydrogen in crystalline semiconductor grain-boundaries and interfaces and of the recent progress in the fundamental study of the mechanisms of hydrogen-interfaces interactions. The interfaces considered are: grain boundaries of polycrystalline semiconductors, semiconductor/semiconductor or semiconductor/metal interfaces, silicon/silicon oxide interfaces (including precipitated silicon oxide interfaces), and semiconductor/electrolyte interfaces. The influence of structural and electronic defects on the hydrogen passivation processes is discussed. Emphasis is laid upon the role of segregated impurities on the electrical activity of interfaces and its subsequent passivation by hydrogen. Some ideas are given for development of experimental and theoretical research to improve the understanding of the mechanisms of hydrogen action.     

Electrochemical aspects of light-induced heterogeneous reactions on semiconductors

Working mechanisms as photocatalyst of semiconductor particles suspended in solution are reviewed with emphasis on photoelectrochemical aspects. Several techniques useful for determination of electronic energy levels of the photocatalysts and for enhancing apparent photocatalytic activities are described, and their utilities are shown in photodecomposition of water on various kinds of semiconductor particles. Studies on detoxification of inorganic and organic wastes are collected as a promising application field of suspended semiconductor photocatalysts. Finally, significance of the use of quantized semiconductor particles as photocatalysts is discussed.