MBE生长Zn_（1－x）Cd_xSe／ZnSe超晶格的SIMS和AES谱

本文简要叙述了运用ＭＢＥ技术成功生长出Ｚｎ１－ｘＣｄｘＳｅ／ＺｎＳｅ超晶格的一些工艺和参数，并对不同的样品进行了ＳＩＭＳ和ＡＥＳ的测试，首次测得了这种材料的元素分布，结果显示ＺｎＣｄＳｅ／ＺｎＳｅ超晶格有着良好的纵向元素分布．     

ZnSe/ZnCdSe多量子阱激子光学非线性

本文采用泵浦－探测技术研究了ＺｎＳｅ／ＺｎＣｄＳｅ多量子阱室温激子饱和吸收，并根据Ｋ－Ｋ关系计算得到５２１．６ｎｍ至５４４ｎｍ的光学非线性折射率的变化．观测到由折射率变化引起的ＺｎＳｅ／ＣｄＺｎＳｅ多量子阱光双稳器件的室温激子光双稳．根据ＺｎＳｅ／ＺｎＣｄＳｅ多量子阱的激子吸收谱及激子的非线性理论，归结其主要非线性机制为激子态的相空间填充和激子带展宽．     

MBE生长Zn1—xCdxSe／ZnSe超晶格的SIMS和AES谱

本简要叙述了运用ＭＢＥ技术成功生长出Ｚｎ１－ｘＣｄｘＳｅ／ＺｎＳｅ超晶格的一些工艺和渗数，并对不同的样品进行了ＳＩＭＳ和ＡＥＳ的测试，首次测得了这种材料的元素分布，结果显示ＺｎＣｄＳｅ／ＺｎＳｅ超晶格有良好的纵向元素分布。     

ZnCdSe—ZnSe／CaF2多量子阱中的三阶非线性

我们首次利用Ｚ－扫描技术在室温下研究了ＺｎＣｄＳｅ－ＺｎＳｅ／ＣａＦ２多量子了进中的三阶非线性，得到非线性系数ｎ２为－４．４６×１０＾－８ｅｓｕ。其主要非线性机理归结为ＺｎＣｄＳｅ－ＺｎＳｅ／ＣａＦ２多量子阱中的带填充效应。     

Zn0.65Cd0.35Se—ZnSe量子阱自电光效应器件的制备和电光调制

利用ＭＯＣＶＤ技术和光电子器件工艺成功制备了Ｐ－ｉ－ｎ结构的Ｐ－ＺｎＳｅ－（Ｚｎ０．６５Ｃｄ０．３５Ｓｅ－ＺｎＳｅＭＱＷ）－ｎ－ＺｎＳｅ自电光效应器件。在这种自由光效应器中，在反向偏置电压下了由量子限制斯塔克效引起的电光调制。     

Zn_（0．65）Cd_（0．35）Se－ZnSe量子阱自电光效应器件的制备和

利用ＭＯＣＶＤ技术和光电子器件工艺成功地制备了Ｐ－ｉ－ｎ结构的Ｐ－ＺｎＳｅ－（Ｚｎ０．６５Ｃｄ０．３５Ｓｅ－ＺｎＳｅＭＱＷ）－ｎ－ＺｎＳｅ自电光效应器件（ＳＥＥＤ）。在这种自由光效应器件中，在反向偏置电压下实现了由量子限制斯塔克效应（ＱｕａｎｔｕｍＣｏｎｆｉｎｅｄＳｔａｒｋＥｆｆｅｃｔ）引起的电光调制。     

光助MOCVD生长p—ZnSe及ZnSep—n结室温蓝色电致发光

用光助低压ＭＯＣＶＤ进行ＺｎＳｅ及ＺｎＳｅ：Ｎ外延层生长，由发光光谱表明，在光助下生长的本征ＺｎＳｅ外延膜具有高质量：ＺｎＳｅ：Ｎ外延层中与Ｎ有关的深中心发射得到有效抑止，其ｐ－ＺｎＳｅ受主载流子深度达３×１０＾１７ｃｍ＾－３。在制备ｎ－ＺｎＳｅ／ＺｎＣｄＳｅ－ＺｎＳｅＱＷ／ｐ－ＺｎＳｅ结构中，在室温下观测到该二极管电脉冲下的蓝色电致发光（ＥＬ）。     

ZnSe多量子阱横向磁阻的无接触测量

用微波无接触法测量了ＺｎＳｅ外延层和两种ＺｎＳｅ多量子阱样品的横向磁阻,在低磁场时,这三种样品都表现为负磁阻,并且也可以用Ｋｈｏｓｌａ和Ｆｉｓｃｈｅｒ的半经验表示式进行拟合,实验还发现了在两层ＺｎＳｅ超晶格之间的Ｚｎ＋Ｇａ单原子层也呈现为较大的负磁阻     

Ⅱ-Ⅵ族宽禁带蓝绿色发光器材料的MBE研究

本文报道ＺｎＳｅ基ⅡⅥ族宽带发光材料分子束外延系统的建立、ｐ型掺杂用等离子体活性氮源的研制、两性掺杂的ＺｎＳｅ材料的生长。实验证明国产ＭＢＥ设备能够自洽生长优质ＺｎＳｅ单晶薄膜；用自制的等离子体活性氮源作受主掺杂剂，获得了ｐＺｎＳｅ单晶薄膜，经ＣＶ测量发现，［Ｎａ］［Ｎｄ］高达～５×１０１７·ｃｍ－３；用国产粉末状ＺｎＣｌ２源作施主掺杂剂，获得了ｎＺｎＳｅ单晶薄膜，Ｈａｌ测量表明［ｎ］高达～２３×１０１９·ｃｍ－３。生长速度均控制在～０５μｍ／ｈ。     

组合多量阱的发光特性研究

通过在７７Ｋ时对ＺｎＣｄＳｅ－ＺｎＳｅ组合多量子阱结构的发光特性的测量,我们观测到了分别来自两组量子阱的激光发光,其跃迁能量与采用包络函数法计算的结果相符。由于两组量子阱之间注入效应的存在,使得两组量子阱在变密度激发和时间分辨光谱中表现出不同的发光特性。     

［（Cdse）_m（ZnSe）_n］_p－Znse多量子阱中的多声子散射

对用原子层外延方法，在［００１］晶向ＧａＡｓ衬底上生长的［（Ｃｄｓｅ）ｍ（Ｚｎｓｅ）ｎ］ｐ－ＺｎＳｅ应变量子阱结构，在１０～３００Ｋ温度范围内测量了喇曼散射光谱，观察到两种类ＺｎＳｅＬＯ声子限制模．利用改变样品温度和入射光能量实现了共振喇曼散射，观察到高达７阶的类ＺｎＳｅＬＯ声子模．并讨论了多声子喇曼散射和热萤光过程的区别．     

静压下（CdSe）_m／（ZnSe）_n－ZnSe超短周期超晶格量子阱的共振喇曼散射研究

在静压和液氮温度下观察到（ＣｄＳｅ）ｍ／（ＺｎＳｅ）ｎ短周期超晶格中重空穴激子的复合发光和多达４阶的类ＺｎＳｅＬＯ多声子喇曼散射，并观察到厚ＺｎＳｅ势垒层的带边发光和限制在厚势垒层中的类ＺｎＳｅＬＯ声子散射．结果表明，加压后（ＣｄＳｅ）ｍ／（ＺｎＳｅ）ｎ短周期超晶格中的类ＺｎＳｅ的１ＬＯ和２ＬＯ声子模频率分别以３．７６和７．１１ｃｍ－１／ＧＰａ的速率向高频方向移动，超晶格阱层光致发光峰的压力系数为５９．８ｍｅＶ／ＧＰａ．与（ＣｄＳｅ）ｍ／（ＺｎＳｅ）ｎ短周期超晶格共振时的类ＺｎＳｅ１ＬＯ声子模频率比与ＺｎＳｅ势垒层共振时的类ＺｎＳｅ１ＬＯ声子模频率低２．０ｃｍ－１，反映了（ＣｄＳｅ）ｍ／（ＺｎＳｅ）ｎ短周期超晶格中ＬＯ声子的限制效应     

3.77-5.05-/spl mu/m tunable solid-state lasers based on Fe/sup 2+/-doped ZnSe crystals operating at low and room temperatures

Spectroscopic properties and lasing of Fe:ZnSe and co-doped Fe:Cr:ZnSe crystals in the mid-infrared spectral range were studied at room and low temperatures. Using a free-running Er:YAG laser as a pump source, the output energy of the thermoelectrically cooled Fe:ZnSe laser was 142 mJ with 30% slope efficiency at T=220 K. Passive Q-switched oscillation of Er:YAG laser with Fe:ZnSe crystal was demonstrated and used as a pump source for a Fe:ZnSe laser system. Room-temperature (RT) gain-switched lasing of Fe:ZnSe was achieved in microchip and selective cavity configurations using Q-switched Er:YAG and Raman-shifted Nd:YAG lasers as pump sources. The microchip laser threshold of 100 mJ/cm/sup 2/ was demonstrated using a Fe:ZnSe crystal without any reflection coatings. A slope efficiency of 13%, oscillation threshold of 1.3 mJ, and tunable oscillation of Fe:ZnSe laser systems over 3.95-5.05 /spl mu/m spectral range were realized at RT.     

The study of nitrogen doping in ZnSe and ZnSe:Te

A comparative study of nitrogen doping in ZnSe and ZnTe has been performed and the results suggest that dopant solubility seems to be the limiting factor, at least under our growth conditions, in obstructing degenerate p-type doping of ZnSe. In an effort to increase the nitrogen acceptor concentration in ZnSe, we have investigated the effects of Te isoelectronic impurity on the nitrogen doping concentration in ZnSe. It was found that the total nitrogen concentration and the nitrogen acceptor concentration are indeed increased, but the room temperature free hole concentration actually drops slightly. Temperature dependent transport measurements were performed and the results show a large increase in compensation ratio as well as a dramatical reduction in hole mobility. The latter is attributed to the tendency for hole localization at the isoelectronic impurity.     

Preparation of photoluminescent and conductive ZnSe:I Crystals by iodine vapor transport

This work is the first part of an investigation on the possibility of using ZnSe single crystals, prepared by chemical transport,as semiconducting materials for optoelectronic devices. Good quality,relatively large cubic single crystals have been self-nucleated and grown in a sealed quartz tube by a somewhat modified Kaldis process which is described.X-ray and electron diffraction as well as observations by a polarizing microscope and EPR have been used to determine the crystalline perfection. These single crystals were also characterized by residual impurities. Some effects of Zn annealing on the electrical and photoluminescent properties are reported too. Key words : ZnSe:I, iodine transport, photoluminescence, resistivity, annealing. Work supported by the : Centre National d’Etudes des Telecommunications (CNET) 92220 BAGNEUX Franae. Agenay under contract N‡ 78 9 B 372/BCJ/PEC.     

在ZnO/Si衬底上ZnCdSe/ZnSe多量子阱的生长与光学特性

在经NH3等离子体氮化的Si(100)衬底上。用等离子体增强化学气相淀积(PECVD)的方法生长了ZnO缓冲层，经X射线衍射(XRD)测量，得到了单一取向的ZnO(0002)膜。在此ZnO缓冲层上利用低压金属有机化学气相淀积(LP-MOCVD)方法生长了较高质量的ZnCdSe／ZnSe量子阱。通过不同阱宽的ZnCdSe／ZnSe量子阱生长和测量，得到了多级共振拉曼峰。从发光谱中可见，在1520nm附近有很强的发光，而在未覆盖ZnO的Si衬底上直接生长的ZnCdSe／ZnSe量子阱结构，其光致发光(PL)谱未见发光。可见，在氮化的Si衬底上覆盖ZnO膜生长的ZnCdSe/ZnSe量子阱质量较好。是一种在Si衬底上生长Ⅱ-Ⅵ族化合物半导体材料的有效方法。     

Cr2+:ZnSe的激光输出和调谐性能

Cr2 :ZnSe具有很宽的吸收带和发射带,是中红外波段优秀的可调谐激光材料.从吸收光谱、发射光谱以及角度调谐输出对Cr2 :ZnSe晶体的激光输出性能进行了研究.采用真空高温扩散法制备Cr2 :ZnSe晶体,获得了高浓度的Cr2 离子掺杂的厚1.7 mm,直径10 mm的薄片ZnSe晶体.使用中心波长2.05 μm,最大输出功率8 W的Tm离子掺杂的光纤激光器抽运,使用平凹腔结构搭建谐振腔,获得了最大平均功率1.034 W,中心波长2.367 μm,线宽10 nm的连续激光输出.利用角度调谐的方法,对Cr:ZnSe晶体的调谐性能进行了研究,在100 nm范围内获得了调谐输出.     

Low pressure MOVPE growth of ZnSe,ZnTe, and ZnSe/ZnTe strained-layer superlattices

ZnSe and ZnTe single-crystal layers have been grown onto (100) GaAs substrates by low-pressure metalorganic vapor-phase epitaxy (LP-MOVPE) using the triethylamine-dimethylzinc adduct [DMZn(NEt₃)] as the zinc precursor. The selenium and tellurium precursors were H₂Se (5% in H₂) and di-isopropyltellurium (DiPTe), respectively. These two semiconductors have been grown with different VI/II molar ratios, at different growth temperatures, and with an overall growth pressure ranging from 40 to 400 Torr. Optimal growth parameters have been determined by optical means for the two materials. This information was then used to grow ZnTe/ZnSe strained-layer superlattices. We have studied structures grown on both ZnSe and ZnTe relaxed buffer layers which display a drastic dependence of the Stokes shift between photoluminescence and the optical bandgap on the nature of the buffer layer. Growth interruptions have been used to optimize the optical properties of the superlattices. Theoretical modeling of superlattice band structures has been performed using results of optical and structural characterizations. Observations of zone center transitions as well as excitons associated with the miniband dispersion of the superlattices are reported, in agreement with the theoretical calculation.     

A new type of structural defects in CdZnSe/ZnSe heterostructures

The changes of structural and photoluminescence (PL) characteristics of MBE-grown CdZnSe/ZnSe single quantum well (QW) structures caused by Cd/Zn interdiffusion were studied by high-resolution X-ray diffraction (HRXRD) and low-temperature PL methods. The PL investigations showed that the increase of Cd content in the QW resulted in the increase of the depth of potential fluctuations in the QW as well as in the decrease of ZnSe cap layer band gap (up to several meV). The HRXRD scans as well as reciprocal space maps measured for symmetrical and asymmetrical diffractions revealed the formation of CdZnSe layers near the QW/ZnSe interface with Cd content of order of several percents. It is found that in some samples, the Cd profile in these layers is rather smooth while in others it is quite abrupt. In the latter case, the partial strain relaxation can occur in these layers.     

Electroluminescence by impact excitation in ZnS:Mn and ZnSe:Mn Schottky diodes

Measurements have been made of the variation of the quantum efficiency of electroluminescence as a function of applied field in ZnS:Mn and ZnSe:Mn Schottky diodes. Under very high fields, the quantum efficiency unexpectedly reaches a maximum and then drops. An explanation is proposed which depends on the details of the band structures of ZnS and ZnSe.