GaAs/Al1-xAs表面单量子阱原位光调制反射光谱研究

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Cd_(1-x)Zn_xTe晶片中Zn组分的室温显微光致发光平面扫描表征

用显微光致发光 (μ- PL)平面扫描的方法对 Cd Zn Te(CZT)晶片进行了研究 .分别在 19μm× 16 μm的缺陷区域进行微米尺度和 7.9mm× 6 .0 mm的大面积范围内进行毫米尺度的逐点 PL 测量 .对测得每一点的 PL 谱进行了拟合 ,得到测量点的禁带宽度等参数 ,其平面分布对应于 CZT中 Zn的组分分布 .统计的结果给出禁带宽度的不均匀性 .对样品进行溴抛光后重复类似的测量 ,结果表明禁带宽度的均匀性大为改善 ,接近了材料组分的真实分布     

PHOTOCONDUCTIVITY OF Cd0.7Mn0.3Se

The photoconductivity spectra of semimagnetic semiconductor Cd0.7Mn0.3Se have been measured at 50-300 K and in the wavelength range of 5500 ? to 8000 ?. It is found that the energy gap of Cd0.7Mn0.3Se changes with the temperature linearly, and the temperature coefficient (dEg/dT) is about -7×10-4 eV/K. A photoconductivity peak which is related to Mn2+ is also found. This peak is located around 1.85 eV, nearly unshifted with variation of the temperature. The possible transition mechanisms in Cd1-xMnxSe have been discussed in the light of group theory and crystal field theory, and the results are in good agreement with experiments.     

应力层多量子阱InGaAs/GaAs的光电流谱研究(英文)

The band configurations of the undoped strained-layer InxGa1-xAs(8 or 15nm)-GaAs(15nm) MQW with x = 0.1,0.15 and 0.2, respectively, have been investigated by photocurrent spectroscopy at the temperature range of 10- 300K. Both intersubband transitions and transitions between confined level and continuum are observed. The photocurrent peak related to the 2s or other excited states of heavy-hole exciton is also observed and the exci-tonic binding energy thus obtained is about 8meV. The valence band offset △Ev is determined to be 0.38 and 0.40 by means of two different methods. Owing to the strain effect, both electrons and heavy holes are confined in the InGaAs layers while light holes in the GaAs layers.     

Cd1-xZnxTe晶片中Zn组分的室温 显微光致发光平面扫描表征

用显微光致发光（μ-PL）平面扫描的方法对CdZnTe(CZT)晶片进行了研究．分别在19μm×16μm的缺陷区域进行微米尺度和7.9mm×6.0mm的大面积范围内进行毫米尺度的逐点PL测量．对测得每一点的PL谱进行了拟合,得到测量点的禁带宽度等参数,其平面分布对应于CZT中Zn的组分分布．统计的结果给出禁带宽度的不均匀性．对样品进行溴抛光后重复类似的测量,结果表明禁带宽度的均匀性大为改善,接近了材料组分的真实分布．     

GaAs/AlGaAs 非对称耦合双量子阱界面混合效应光荧光谱研究

用分子束外延系统生 长了GaAs/AlGaAs非对称耦合双量子阱(ACDQW),用组合注入的方法,在同一块衬底上获得了不 同注入离子和不同注入剂量的耦合量子阱单元,没有经过快速热退火过程,在常温下测量了不 同单元的显微光荧光谱,发现子带间跃迁能量最大变化范围接近100meV,组合注入所导致的能 量移动要大于单独注入导致的能量移动.     

GaAs／AlGaAs多量子阱红外探测器研究

ＧａＡｓ／ＡｌＧａＡｓ多量子阱红外探测器研究沈学础，陆卫（上海技术物理研究所上海２０００８３）本文所作的研究包括：１．基本物理机制研究在理论上研究了子带间跃迁的基本物理过程，并提出了ｎ型非（１００）方向生长的ＧａＡｓ／ＡｌＧａＡｓ材料存在的正入射条件...     

V形GaAs/AlGaAs量子线结构的微区光致发光谱研究

在室温下用显微光致发光的方法对单根V形GaAs/AlGaAs量子线进行了沿垂直于量子线方向的 空间分辨扫描测试,观察到各种量子结构的光致发光谱随空间位置的变化.在量子线区域附 近观察到来自量子线(QWR)、颈部量子阱(NQWL)和垂直量子阱(VQWL)等各种结构的发光,而 在距离量子线约1μm以远的发光光谱表现出侧面量子阱(SQWL)的发光.对全部发光光谱用高 斯线形进行了拟合,发现QWR和SQWL的发光包含了两个荧光峰,将它们分别归诸为电子到轻 、重空穴的跃迁.拟合后发光强度的空间变化直接确定了与量子线 关键词： V形GaAs/AlGaAs量子线 显微光致发光 空间分辨扫描     

隐身技术和物理

随着目标探测技术的不断提高，隐身技术已成为现代战争中提高武器装备生存力和战斗力的关键技术，介绍了隐身的概念，重点讨论了雷达隐身和红外隐身领域的一些常用技术，研究了不同电磁小段隐身手段的相互制约以及兼容的可能性，虽然隐身技术起源于战争，但无庸置疑，隐身技术和物理学的紧密联系，以及它在国民经济非军事领域中的多方面应用必将会引起物理学家，工业企业界人士的密切关注。     

Reentrant Spin Glass Behaviour and CE-Type Antiferromagnetic Phase in Half Doping （La,Pr）1／2Ca1／2 MnO3 Manganites

The reentrant spin glass behaviour was observed in half doping (La,Pr)1/2Ca1/2MnO3 manganites with a CEtype antiferromagnetic structure. It shows sequential multiple magnetic transitions from the paramagnetic to the ferromagnetic, antiferromagnetic, spin glass (SG) transitions, which reflects the complex magnetic interaction in the ground state of manganites. This can be explained by the competition interaction between the ferromagnetic and the CE-type antiferromagnetic matrix, and the disorder due to the tolerance factor t and A-cation size variance σ^2. The results reveals the coexistence of ferromagnetic clusters and SG clusters in the background of the antiferromagnetic matrix in the ground state of half doping (Pr,La)1/2Ca1/2MnO3 systems.