分子束外延CdTe（211）B／GaAs（211）B的特性研究

ＣｄＴｅ／ＧａＡｓ是ＨｇＣｄＴｅ分子束外延的重要替代衬底材料。用Ｘ双晶衍射和光致发光测试研究了分子束外延生长的ＣｄＴｅ（２１１）Ｂ／ＧａＡｓ（２１１）Ｂ的晶体结构质量，表明外延膜晶体结构完整，具有很高的质量。用高分辨率的透射电镜研究其界面特性，观察到ＣｄＴｅ（２１１）Ｂ相对于ＧａＡｓ（２１１）Ｂ向着［１１１］方向倾斜一个小角度（约３°），界面的四面体键网发生扭曲，由于晶格失配，在界面存在很高的失配位错密度。用二次离子质谱分析仪分析了ＧａＡｓ衬底中的Ｇａ和Ａｓ向ＣｄＴｅ外扩散的情况。结果表明：如果要在ＧａＡｓ衬底上生长ＨｇＣｄＴｅ外延膜，必须先生长一层具有一定厚度的ＣｄＴｅ来阻止Ｇａ和Ａｓ向ＨｇＣｄＴｅ的外扩散和失配位错的延伸。     

分子束外延CdTe（211）B／GaAs（211）B的特性研究

ＣｄＴｅ／ＧａＡｓ是ＨｇＣｄＴｅ分子束外延的重要替代衬底材料。用Ｘ双晶衍射和光致发光测试研究了分子束外延生长的ＣｄＴｅ（２１１）Ｂ／ｇＡｓ（２１１）Ｂ的晶体结构质量，表明外延膜昌体结构完整，具有很高的质量。用高分辨率的透射电镜研究其界面特性，观察到ＣｄＴｅ（２１１）Ｂ相对于ＧａＡｓ（２１１）Ｂ向着（１１１）方向倾斜一个小角度，界面的四面体键网发生扭曲，由于晶格失配，在界面存在很高的失配位错密度。     

B离子在n（Si）－GaAs层中的化学补偿效应

Ｂ＋注入ｎ（Ｓｉ）－ＧａＡｓ层，经高温退火在ＧａＡｓ晶格恢复过程中，Ｂ将占据ＧａＡｓ晶格中一定位置成为替位Ｂ，当Ｂ取代Ａｓ位，则形成双受主ＢＡｓ．当Ｂ取代Ｇａ位，并形成络合物ＢＧａＶＡｓ，将促使Ｓｉ占Ａｓ位，形成受主ＳｉＡｓ和受主络合物ＢＧａＳｉＡｓ．由于所产生的受主与ｎ型层中施主ＳｉＧａ的补偿，减少了ｎ型层的载流子浓度，即Ｂ的化学补偿效应．本文采用霍耳测量及光致发光测量对Ｂ的补偿行为进行分析．     

用MOCVD在非平面衬底上生长的量子阱、量子线及其光学性质

本文报道在６５０℃的衬底温度下实现了ＭＯＣＶＤ在（１００）面和（１１１）面上生长ＧａＡｓ与Ａｌ０．４Ｇａ０．６Ａｓ的不同的选择性．这一衬底温度比国际上以前报道的要低，对制作适于光电器件的ＧａＡｓ／ＡｌＧａＡｓ量子阱层比较有利．用此技术，在ＧａＡｓ非平面衬底上生长了ＧａＡｓ／Ａｌ０．４Ｇａ０．６Ａｓ量子阱，并用扫描电镜、低温光致发光谱以及偏振激发的光反射率谱技术进行了研究．结果不仅证明了ＭＯＣＶＤ外延生长ＧａＡｓ和Ａｌ０．４Ｇａ０．６Ａｓ的独特选择性，也证明了在Ｖ字形沟槽底形成了量子线．     

用MOCVD在非平面衬底上生长的量子阱,量子线及其光学性质

本文报道在６５０℃的衬底温度下实现了ＭＯＣＶＤ在（１００）面和（１１１）面上生长ＧａＡｓ与Ａｌ０．４Ｇａ０．６Ａｓ的不同选择性。这一衬底温度比国际上以前报道的要低，对制作适于光电器件的ＧａＡｓ／ＡｌＧａＡｓ量子阱层比较有利。用此技术，在ＧａＡｓ非平面衬底上生长了ＧａＡｓ／Ａｌ０．４Ｇａ０．６Ａｓ量子阱，并用扫描电镜、低温光致发光谱及偏振激发的光反射率谱技术进行了研究。结果不仅证明了ＭＣＣＶＤ外延生     

B廓了在n（Si）—GaAs层中的化学补偿效应

Ｂ注入ｎ（Ｓｉ）－ＧａＡｓ层，经高温退火在ＧａＡｓ晶格恢复过程中，Ｂ将占据ＧａＡｓ晶格中一定位置成为替位Ｂ，当Ｂ取代Ａｓ位，则形成双受主ＢＡｓ，，当Ｂ取代Ｇａ位，并形成络合物ＢＧａＹＡｓ，将促使Ｓｉ占Ａｓ位，形成受主ＳｉＡｓ和受主络合物ＢｇａＳｉＡｓ，由于所产生的受主与ｎ层中施主ＳｉＧａ的补偿，减少了ｎ 的载流子浓度，即Ｂ的化学补偿效应，本采用霍测量及光致光发测量对Ｂ的补偿行为进行分析。     

（100）和（111）BGaAs衬底上的In_（0．14）Ga_（0．86）As／GaAs量子阱的发光特性和光跃迁能量计算

在（１００）和（１１１）ＢＧａＡｓ衬底上，同时用ＭＯＣＶＤ生长出Ｉｎ０．１４Ｇａ０．８６Ａｓ多量子阱结构．对两种晶向的样品进行了低温（２Ｋ）光致发光谱特性对比研究，测量与理论计算的光发射能量对比表明：（１００）面样品两者一致，而（１１１）Ｂ样品计算值比测量值高出１０～１５ｍｅＶ．这一差别用（１１１）Ｂ面量子阱中的压电效应产生的自建电场引起的发射能量红移作出解释．     

GaAs／Al_xGa_（1－x）As多量子阱掩埋条形激光器

利用ＭＢＥ生长的ＧａＡｓ／ＡｌｘＧａ１－ｘＡｓ折射率渐变－分别限制－多量子阱材料（ＧＲＩＮ－ＳＣＨ－ＭＱＷ），经液相外延二次掩埋生长，制备了阈值最低达２．５ｍＡ（腔面未镀膜），光功率室温连续输出可达１５ｍＷ／面的半导体激光器．经腔面镀膜后，器件已稳定工作４５００多小时．     

新结构高性能In_（0．3）Ga_（0．7）As／In_（0．29）Al_（0．

新结构高性能Ｉｎ_（０．３）Ｇａ_（０．７）Ａｓ／Ｉｎ_（０．２９）Ａｌ_（０．７１）Ａｓ／ＧａＡｓＨＥＭＴ研究证明，ＩｎＧａＡｓＨＥＭＴ的结构优于ＧａＡｓＭＥＳＦＥＴ和习用的ＡｌＧａＡｓ／ＧａＡｓＨＥＭＴ。在ＧａＡｓ上制备的赝配结构ＨＥＭＴ（ＰＭ－ＨＥ...     

（100）和（111）BGaAs衬底上的In0.14Ga0.86As／GaAs量子阱的发光特性…

在（１００）和（１１１）ＢＧａＡｓ衬底上，同时用ＭＯＣＶＤ生长出Ｉｎ０．１４Ｇａ０．８６Ａｓ多量子阱子结构，对两种晶向的样品进行了低温（２Ｋ）光致发光谱特怀性地比研究，测量与理论的光发射能量对比表明；（１００）面样品两一致，而（１１１）Ｂ样品比测量值高出１０－１５ｍｅＶ，这一差别用（１１１）Ｂ面量子阱中的压电效应产生的知建电场引起的发射能量红移作出解释。     

Lateral ordering of GaAs nanowhiskers on GaAs(111)As and GaAs (110) surfaces during molecular-beam epitaxy

Possibilities of obtaining laterally ordered arrays of GaAs nanowhiskers on GaAs (110) and GaAs(111)As surfaces during the molecular beam epitaxy are considered. As in the case of the GaAs(111)As substrate, nanowhiskers are formed in the hexagonal phase on the GaAs(110) surface, which is also confirmed by the patterns of the reflection high-energy electron diffraction (obtained during the growth of nanowhiskers) and by the photoluminescence spectra.     

Structural and photoluminescence properties of low-temperature GaAs grown on GaAs(100) and GaAs(111)A substrates

Undoped, uniformly Si-doped, and δ-Si-doped GaAs layers grown by molecular-beam epitaxy on (100)- and (111)A-oriented GaAs substrates at a temperature of 230°C are studied. The As₄ pressure is varied. The surface roughness of the sample is established by atomic-force microscopy; the crystal quality, by X-ray diffraction measurements; and the energy levels of different defects, by photoluminescence spectroscopy at a temperature of 79 K. It is shown that the crystal structure is more imperfect in the case of GaAs(111)A substrates. The effect of the As₄ flux during growth on the structure of low-temperature GaAs grown on different types of substrates is shown as well.     

GaAs inversion-base bipolar transistor (GaAs IBT)

A completely new type of GaAs bipolar transistor with a base formed by a two-dimensional hole gas has been fabricated. The transistor has no metallurgical base layer but has an extremely thin inversion hole layer working as a base layer. The current gain β = 5.6 at 77 K and β = 17.1 at 300 K was obtained for the common emitter mode.     

Long-wavelength GaInNAs(Sb) lasers on GaAs

The boom in fiber-optic communications has caused a high demand for GaAs-based lasers in the 1.3-1.6-μm range. This has led to the introduction of small amounts of nitrogen into InGaAs to reduce the bandgap sufficiently, resulting in a new material that is lattice matched to GaAs. More recently, the addition of Sb has allowed further reduction of the bandgap, leading to the first demonstration of 1.5-μm GaAs-based lasers by the authors. Additional work has focused on the use of GaAs, GaNAs, and now GaNAsSb barriers as cladding for GaInNAsSb quantum wells. We present the results of photoluminescence, as well as in-plane lasers studies, made with these combinations of materials. With GaNAs or GaNAsSb barriers, the blue shift due to post-growth annealing is suppressed, and longer wavelength laser emission is achieved. Long wavelength luminescence out to 1.6 μm from GaInNAsSb quantum wells, with GaNAsSb barriers, was observed. In-plane lasers from these samples yielded lasers operating out to 1.49 μm, a minimum threshold current density of 500 A/cm² per quantum well, a maximum differential quantum efficiency of 75%, and pulsed power up to 350 mW at room temperature     

ZnSe heteroepitaxy on GaAs (110) substrate

ZnSe heteroepitaxial layers have been grown on GaAs (100), (110) on axis, and (110) 6° miscut substrates by molecular beam epitaxy. ZnSe on GaAs (110) shows smooth and featureless spectra from Rutherford backscattering channeling measurements taken along major crystalline directions, whereas ZnSe on GaAs (100) without pre-growth treatments exhibit large interface disorder in channeling spectra. ZnSe films grown on GaAs (110) on axis show facet formation over a wide range of growth conditions. The use of (110) 6° miscut substrates is shown to suppress facet formation; and under the correct growth conditions, facet-free surfaces are achieved. Etch pit density measurements give dislocation densities for ZnSe epitaxial layers grown on GaAs (100), (110) on axis, and (110) 6° miscut substrates of 10⁷/cm², 3 × 10⁵/cm² and 5 × 10⁴/cm², respectively. These results suggest that with further improvements to ZnSe growth on GaAs (110)-off substrates it may be possible to fabricate defect free ZnSe based laser devices.     

GaAs(001)基底取向误差对GaAs/Al_(0.3)Ga_(0.7)As中局域声子的影响(英文)

We have studied the confined phonons in GaAs/Al0 3Ga0.7As superlat-tice grown by molecular beam epitaxy on oriented and misoriented GaAs (001) substrates. Raman scattering measurements have been performed at room- and low-temperatures. The results show that the phonon features in the superlattice-grown on GaAs(001) misoriented 4° toward the [110] direction are significantly different from those in the precisely oriented sample. The difference is discussed in terms of misorientation induced atomic-steps at GaAs-Al0.3Ga0.7As interfaces.     

三组三元合金异质结的价带带阶

采用基于LMTO－ASA的平均键能计算方法和原子集团展开方法，研究了三组典型的晶格匹配三元合金异质结（GaAs）x（Ge2）1-x／GaAs，（AlAs）x（Ge2）1-x／GaAs和AlxGa1-xAs／GaAs的价带带阶△Ev（x）值。研究表明：AlxGa1-xAs／GaAs异质结的Mv（x）值随合金组分x的变化接近于线性；（GaAs）x（Ge2）1-x／GaAs和（AlAs）x（Ge2）1-x／GaAs的△Ev（x）值随合金组分x的变化是非线性的。△Ev（x）的理论计算值与实验结果相当符合。     

Terahertz-radiation generation and detection in low-temperature-grown GaAs epitaxial films on GaAs (100) and (111)A substrates

The efficiency of the generation and detection of terahertz radiation in the range up to 3 THz by LT-GaAs films containing equidistant Si doping δ layers and grown by molecular beam epitaxy on GaAs (100) and (111)Ga substrates is studied by terahertz spectroscopy. Microstrip photoconductive antennas are fabricated on the film surface. Terahertz radiation is generated by exposure of the antenna gap to femtosecond optical laser pulses. It is shown that the intensity of terahertz radiation from the photoconductive antenna on LT-GaAs/GaAs (111)Ga is twice as large as the intensity of a similar antenna on LT-GaAs/GaAs(100) and the sensitivity of the antenna on LT-GaAs/GaAs (111)Ga as a terahertz-radiation detector exceeds that of the antenna on LT-GaAs/GaAs(100) by a factor of 1.4.     

Trapezoidal-groove Schottky-gate vertical-channel GaAs FET (GaAs static induction transistor)

This letter reports, the development of a vertical-channel. GaAs FET with the unsaturatedI-Vcharacteristics of the static induction transistor (SIT) and voltage blocking capability up to 100 V. The device structure utilizes the anisotropic etching properties of GaAs, in which the gate regions are formed by a double-angle evaporation into trapezoidal etched grooves. This single evaporation step simultaneously provides both source and gate metallization, and the novel trapezoidal groove geometry automatically yields a self-aligned gate with separation of source and gate onto different levels, thus eliminating the need for critical alignment arising from source-gate interdigitation.     

Optical properties of GaAs/AlAs superlattices grown on (311)A GaAs surfaces

We present a temperature-dependence photoluminescence of (GaAs)₅/(AlAs)₅ superlattice grown on (311)A-oriented semi-insulating substrate by molecular beam epitaxy. The temperature dependence reveals an anomalous decrease of the PL width, which is explained in terms of phonon-assisted thermal activation of localized excitons.