GaAs皮秒光电开关

利用大功率激光器和半导体的光敏性,可得到幅度数千伏,具有皮秒级上升时间和小于2皮秒抖动的电脉冲,本文讨论了这种开关的原理及得到的实验结果。     

GaAs探测器实验标定

叙述了在闪光Ⅰ上用6MV轫致辐射实验标定快响应GaAs光电探测器的原理实验结果以及分析讨论。     

GaAs太阳电池的现状

自从前几年出现能源危机以来,太阳光作为“无污染”的能源引起了人们的注意,仅在这数年内,关于太阳光发电的研究就得到了飞速发展。但是,使用太阳电池大规模发电还是十年以后的计划,目前正处在探讨Si以及Ⅲ—Ⅴ族,Ⅱ—Ⅵ族化合物太阳电池的性能和经济前景以及今后发展方向的时期。本文针对Ⅲ—Ⅴ族化合物,尤其是GaAs系太阳电池的以前研究过程、现状和今后应该发展的技术等,展望GaAs太阳电池的将来。     

GaAs中的离子注入技术

在ＧａＡｓ集成电路和器件研制中，离子注入是关键技术之一．介绍了用离子注入ＧａＡｓ形成ｎ型和ｐ型区，以及离子注入ｐ型和ｎ型ＧａＡｓ形成绝缘层、形成ｎ＋ＧａＡｓ深埋层等重要技术．对有关物理机制进行了讨论并提出了一些新见解；该离子注入新工艺已经应用于ＧａＡｓ器件和集成电路的研制，获得了多种新型器件． Optical and electrical properties of Si GaAs wafers implanted with Si+, S+, Be+, Mg+, B+, O+ have been investigated in this paper.     

GaAs1-xSbx/GaAs单量子阱的光学特性研究

用选择激发光荧光研究了分子束外延生长的GaAsSb/GaAs单量子阱的光学性质,第一次同时观察到空间直接(Ⅰ类)和间接(Ⅱ类)跃迁.它们表现出不同的特性:Ⅰ类跃迁具有局域化特性,其发光能量不随激发光能量而变;Ⅱ类发光的能量位置随激发功率的增大而蓝移,也随激发光能量的增加而蓝移,复合发光发生在位于异质结GaAs一侧的电子和GaAsSb中的空穴之间,实验结果可以很好地用电荷分离造成的能带弯曲模型来解释,这也是空间间接跃迁的典型特性.还用光荧光的激发强度关系和时间分辨光谱进一步论证了GaAsSb/GaAs能带排列的Ⅱ类特性,并通过简单计算得到了应变和非应变状态下GaAsSb/GaAs异质结的带阶系数.     

微微秒GaAs光电闸门

研制出具有20μm间隙的微带型Cr:GaAsps光电闸门.用锁模氩离子激光器同步泵浦的染料激光器照射,用上升时间30ps取样示波器监测,得到输出电脉冲120ps的上升时间和230ps的半极大全宽度(FWHM).在30V直流偏压下,38pJ～320pJ激光脉冲能量范围内,给出输出电脉冲峰压与光脉冲能量之间的线性关系实验曲线.     

GaAs1—xPx晶体生长

最近Ⅲb—Ⅴb族化合物半导体做为注入型发光元件材料,已被广泛地应用。其中最引人注意的可见发光材料是Ga_1—xAlxAs、GaAs_1—xPx、GaP等含Ga的化合物半导体。从晶体生长方法,发光区域的形成方式以及发光特性来看,这些化合物都具有自己     

Transient characteristics of the InGaP–GaAs–InGaAs–GaAs transistor laser

Transient characteristics of the InGaP–GaAs–InGaAs (quantum well)-GaAs transistor laser are studied. Rate equations are numerically solved to obtain the response of current density and photon density. Expression of resonance frequency $f_{r}$ is obtained by solving the rate equations analytically. It has been found that the $f_{r}$ increases with decreasing spontaneous carrier lifetime and with increasing value of the bias current density.     

离子注入GaAs的脉冲激光退火

利用沟道背散射、俄歇和X射线光电子能谱技术研究了Nd:YAG和红宝石脉冲激光退火的离子注入GaAs样品的表面性质。结果表明,对于这两种激光都存在一个从无定形向单晶转化的阈值能量,在阈值能量附近,没有明显的表面分解。高能量密度可引起明显的分解和损伤。利用热流理论计算了杂质的再分布。对于两种激光都得到了Te在GaAs中较高的替位率。 关键词：     

GaAs光电阴极微光象管

封接在透明窗上的GaAs光电阴极,这一新的改进,对微光象管很有吸引力(图1)。为了制造这种类型的管子,必需具备超高真空传递装置(图2),因为只有在严格规定超高真空条件下,GaAs表面才被完全净化,并且由Cs和O_2的表面吸附产生负电子亲和势时,CaAs光电阴极才能获很高逸出几率。通过加热上述材料使半导体表面净化;其加热的最高温度受GaAs光电阴极表面的分解     

GaAs真空电子源衰减模型研究

利用X射线光电子能谱(XPS)仪对激活后的GaAs真空电子源进行了随时间衰减变化的XPS分析,分析发现了电子源阴极表面各元素百分含量随时间的变化,揭示了杂质气体吸附造成的偶极矩方向的改变是电子源灵敏度显著下降的主要原因.基于上述结论,通过分析真空系统中杂质气体的吸附过程,推导并得到了GaAs电子源衰减模型.该模型从理论上揭示了GaAs电子源的指数衰减规律以及寿命与真空度的反比关系,与实验现象完全一致. 关键词： 电子源 X射线光电子能谱 衰减模型 真空度     

GaAs的中子嬗变掺杂

硅的中子嬗变掺杂(NTD)已经得到了广泛应用,在制备大功率整流器、可控硅、硅靶摄像管、核探测器和集成电路等方面巳被公认是一个好的方法[1-3].NTD硅的优点是掺杂十分均匀,浓度偏差可在±5%之内,而且它的掺杂精度很高,能够准确地达到所要求的浓度. 1971年苏联的 Sh.M.Mirishvili等人[4]报道了GaAs的中子嬗变掺杂,在这以后,一些作者进一步研究了热中子辐照GaAs的原理、光致发光性质及其应用[5-8]. 用常规掺杂方法在砷化棕中引入施主杂质时,总是伴随着受主浓度的增加.在掺杂浓度较低时,n型GaAs具有明显的补偿,。。/。。一般超过0.3,而在…     

Growth and Characterization of GaAs／A1GaAs Thue-Morse Quasicrystal Photonic Bandgap Structures

One-dimensional quasicrystal structures composed of Ⅲ-Ⅴ semiconductor GaAs/AlGaAs multilayers in deterministic Thue-Morse (TM) sequences have been grown by using gas-source molecular beam epitaxy to investigate both the structural and the photonic bandgap properties. The x-ray measurements show that this aperiodic system exhibits obvious periodic spatial correlations, from which the precise thickness of the constitutive layers could be determined. Transmission and reflection measurements experimentally demonstrated plenty of photonic bandgaps with traditional or fractal features existing in those quasicrystal structures, which are in good agreement with the transfer matrix simulations. The diversity of this TM system makes it a good candidate for photonic device applications.     

透射式GaAs光电阴极AlGaAs/GaAs外延层倒易点二维图分析

本文介绍了摇摆曲线和倒易点二维图在评价晶格完整性时的特点,分析了透射式GaAs光电阴极样品AlGaAs/GaAs外延层的倒易点二维图,获得了晶面弯曲以及AlGaAs外延层中Al组份变化等方面的信息,为优化外延工艺提供了可靠的保证.     

Magnetic properties of GaAs/δ〈Mn〉/GaAs/In x Ga1 − x As/GaAs quantum wells

The field and temperature dependences of the magnetization of GaAs/δ〈Mn〉/GaAs/In _x Ga_{1 ? x} As/GaAs quantum wells with the δ〈Mn〉 layer separated from the well by a 3-nm GaAs spacer have been studied in the temperature range of 3–300 K in a magnetic field up to 6 T. An external magnetic-field-induced phase transition to a ferromagnetic state with a magnetization hysteresis loop shifted from a zero magnetic field has been found to occur at a temperature below 40 K. A theoretical model is proposed that implies the coexistence of ferromagnetically and antiferromagnetically ordered regions within the GaAs layers.     

关于GaAs的低迁移率问题

测量了5个不掺杂LPE-GaAs样品的电子迁移率温度关系,发现不同样品的诸曲线有互相交叉的现象,只用离化杂质散射一种非本征机制难于解释它。因此,假设未知散射中心(mobilitykiller)的存在看来是必要的。由于被研究的样品的纯度已相当高,Stringfellow等人所假设的杂质中心元胞势散射可以忽略不计。分析了光照对77K温度下电子浓度和迁移率的影响,认为未知散射中心可能是样品微观不均匀性造成的空间电荷区。 关键词：     

Ferromagnetic transition in GaAs/Mn/GaAs/In x Ga1 − x As/GaAs structures with a two-dimensional hole gas

The transport properties of GaAs/Mn/GaAs/In _x Ga_{1 ? x} As/GaAs structures with a layer that is separated from the quantum well and contains Mn impurities in the concentration range 4–10 at % corresponding to the reentrant metal-insulator transition observed in the bulk GaMnAs material [17] have been investigated. The hole mobility in the objects under investigation is more than two orders of magnitude higher than the known values for the GaMnAs semiconductor and GaMnAs-based magnetic heterostructures. This makes it possible to observe Shubnikov-de Haas oscillations, which confirm a two-dimensional character of the hole energy spectrum. The calculated Curie temperature for heterostructures with indirect exchange interaction through a two-dimensional hole channel is in good agreement with the position of the maximum (at 25–40 K) in the temperature dependences of the electrical resistance of the channel. This suggests that two-dimensional holes play an important role in ferromagnetic ordering of the Mn layer under these conditions. The observations of a negative spin-dependent magnetoresistance and an anomalous Hall effect, whose magnitude correlates well with the results of theoretical calculations for two-dimensional ferromagnetic systems based on III-Mn-V, also indicate a significant role of the two-dimensional channel in ferromagnetic ordering.     

透射式GaAs光电阴极研究

本文叙述了透射式GaAs光电阴极的原理和制作过程,详细地研究了透射式GaAs光阴极的激活工艺,获得了500μA/1m的积分灵敏度.     

GaAs表面硫钝化研究新进展

ＧａＡｓ及其他Ⅲ－Ⅴ族半导体表面钝化一直是人们感兴趣的研究课题,在半导体器件制造工艺的发展中起着重要的作用,文章着重从钝化方法和钝化机理两方面简单地回顾了近年来ＧａＡｓ表面硫钝化的最新研究进展。     

高功率单模GaAlAs/GaAs激光器

本文报告了隐埋双脊衬底大光腔结构GaAlAs/GaAs激光器的制备和特性,获得CW光输出的最高功率可达80mW。