天宫二号ZnTe:Cu晶体生长及能谱分析（英文）

在微重力条件下生长了ZnTe:Cu晶体,对其进行了光学和能谱分析,在晶锭尾部最大结晶区对其进行了组分分析.对于尾部的轴向分量,在空间样品中Cu的成分均匀性优于地面样品,并且Te/Zn比的样品高于空间样品.尾部空间样品中Cu的径向成分均匀性优于地面样品,且Te偏析更为严重.     

对在10~(-4)g环境中淬火的Cd_(0.21)Hg_(0.79)Te的分析

一个95g的Cd_(0.21)Hg_(0.79)Te样品在10~(-4)g环境中固化。红外透射分析表明其径向和轴向均一性都比地面样品有显著改善。本文概述了这次试验及其结果。     

微重力ZnTe：Cu 晶体生长及阴极荧光光谱(CL)分析

利用Te熔剂方法,在天宫二号飞船上成功地生长了ZnTe:Cu晶体.微重力下生长的晶体质量优于地面生长的晶体,相同实验条件下,天宫二号上生长的晶体尺寸明显大于地面尺寸.通过阴极荧光光谱(CL)无损检测技术测试了5 kV、15 kV、25 kV高压下的ZnTe:Cu晶体的阴极荧光图谱及光谱.     

Cd_(1-x)Zn_xTe多晶薄膜的制备、性能与光伏应用

用共蒸发法制备了 Cd1 - x Znx Te多晶薄膜 ,薄膜结构属立方晶系空间群 F4 3m.通过透射光谱的测量 ,计算光能隙 ,得到室温时薄膜的光能隙随组分 x值的变化满足二次方关系 .作为对异质结界面的修饰 ,提出了有 Cd1 - x-Znx Te过渡层的 Cd S/ Cd Te/ Cd1 - x Znx Te/ Zn Te∶ Cu电池 .并在相同工艺下制备了 Cd S/ Cd Te/ Cd0 .4 Zn0 .6 Te/ Zn Te∶ Cu与 Cd S/ Cd Te/ Zn Te∶ Cu太阳电池 ,发现前者比后者效率平均增加了 35 .0 % .     

微重力条件下生长GaAs单晶的电学和光学性质研究

用多种实验手段分别对地面和太空生长的掺Te砷化镓单晶的电学、光学均匀性和深能级行为进行了实验研究.初步结果表明:在太空进行再生长的GaAs单晶电子浓度比原地面生长的籽晶小一个数量级,电子浓度由地面晶体到太空晶体的过渡是陡变的;DLTS测量发现太空单晶中存在两个电子陷阱,分别位于导带下0.27eV和0.60eV处,深能级密度为浅施主N_D的10~(-3)-10~(-4);少子注入未观察到空穴陷阱;用太空GaAs单晶为衬底制备的25个单异质结(SH)二极管,具有一致的I-V和发光特性,这反映了太空晶体的均匀性优于地面晶体.此外,还对太空生长GaAs单晶电子浓度降低的可能原因、深能级行为以及太空生长高质量晶体的前景作讨论.     

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     

磁控溅射法制备Bi2Te3热电薄膜的研究

Bi2Te3薄膜是室温下热电性能最好的热电材料,利用磁控溅射在长有一薄层SiO2的n型硅样品上制备Bi/Te多层复合薄膜,经后续退火处理生成Bi2Te3。通过分析Bi2Te3薄膜的生长和退火工艺,探讨Bi/Te中Te的原子数分数对薄膜热电性能的影响。采用XRD和SEM对薄膜的结构、形貌和成分进行分析,并测量不同条件下的Seebeck系数。薄膜Seebeck系数均为负数,表明所制备样品是n型半导体薄膜,且最大值达到-76.81μV.K-1;电阻率ρ随Te的原子数分数增大而增大,其趋势先缓慢后迅速。Bi2Te3薄膜的热电性能良好,Te的原子数分数是60.52%时,功率因子最大,为1.765×10-4W.K-2.m-1。     

ZnTeCu薄膜的制备及其性能

用共蒸发法在室温下沉积了 Zn Te∶ Cu多晶薄膜 .刚沉积的不掺 Cu的薄膜呈立方相 ,适度掺 Cu时为立方相和六方相的混合相 .随着 Cu含量的增加 ,六方相增加 ,光能隙减小 .根据暗电导温度关系 ,结合 XRD和 DSC的结果 ,认为在 110℃、170℃开始出现类 Cu Te、类 Cu2 Te相以及 Cu0、Cu+离解的结果导致电导温度关系异常 ,应用这种薄膜作为背接触层获得了转换效率为 11.6 % ,面积为 0 .5 2 cm2 的 Cd S/Cd Te/Zn Te∶ Cu太阳电池     

ZnTe Cu薄膜的制备及其性能

用共蒸发法在室温下沉积了 Zn Te∶ Cu多晶薄膜 .刚沉积的不掺 Cu的薄膜呈立方相 ,适度掺 Cu时为立方相和六方相的混合相 .随着 Cu含量的增加 ,六方相增加 ,光能隙减小 .根据暗电导温度关系 ,结合 XRD和 DSC的结果 ,认为在 110℃、170℃开始出现类 Cu Te、类 Cu2 Te相以及 Cu0、Cu+离解的结果导致电导温度关系异常 ,应用这种薄膜作为背接触层获得了转换效率为 11.6 % ,面积为 0 .5 2 cm2 的 Cd S/Cd Te/Zn Te∶ Cu太阳电池     

远红外Ge-Ga-Te-Cu硫系玻璃光学性能研究

采用传统的熔融-淬冷法制备了一系列Cu改良后的GeTe4-Ga2Te3玻璃样品,利用X射线衍射(XRD)、扫描电子显微镜(SEM)、差热分析(DTA)、分光光度计和红外透射光谱仪等研究了系统玻璃组成、结构和光学特性,应用经典的Tauc方程计算了样品光学带隙允许的间接跃迁。实验结果表明,玻璃的密度和摩尔体积都随着Cu含量的增加而减小,短波吸收截止边发生红移,光学带隙减小;(GeTe4)68(Ga2Te3)26Cu6玻璃具有最好的热稳定性,ΔT(=Tx-Tg,即玻璃的析晶温度值Tx与玻璃转变温度值Tg的差值)为103℃所有的玻璃样品都有很宽的红外透过窗口,红外截止波长都超过了20μm,表明Te基硫系玻璃材料在远红外应用方面有着巨大的潜在开发     

HgCdTe体晶的组份均匀性分析

利用ＳＰＲＩＴＥ探测器的截止波长研究了布里奇曼、Ｔｅ溶剂和固态再结晶３种方法制备的ＨｇＣｄＴｅ体晶组份的均匀性。实验结果表明：３种方法生长的ＨｇＣｄＴｅ晶片的组份均匀性大致相当。用任意一种材料研制的一个８条ＳＰＲＩＴＥ探测器,其任意２条的截止波长差不大于０．８μｍ的概率大于９８％。     

Cd1—xZnxTe晶体生长技术进展

介绍了Cd_(1-x)Zn_xTe晶体生长国外新进展和国内研究动态。指出Cd(1-x)Zn_xTe晶体研究正在向大面积单晶,组分和结构高均匀性,低位错密度和定向生长等方面发展     

提高红外器件磁控溅射沉积镀膜厚度均匀性的一种方法

介绍了一种提高红外器件磁控溅射沉积镀膜厚度均匀性的方法。这种方法被称为基片离心旋转法,是在保持磁控溅射靶不动及靶和样品台间距不变的情况下,通过样品台离心旋转的方法,补偿或改善圆形磁控靶在正对的基片上沿径向的溅射沉积不均匀分布,是一种动态沉积法。这种方法可以在不改变磁控靶结构的情况下大大提高磁控溅射沉积镀膜的厚度均匀性。     

液相外延HgCdTe薄膜组分均匀性对红外透射光谱的影响

用多层模型和膜系传递矩阵计算了HgCdTe/CdZnTe外延薄膜的红外透射光谱，结果表明组分扩散区主要影响透射光谱的干涉条纹和透射率小于10％的区域，而组分梯度区则影响吸收边斜率．横向组分波动也将影响透射光谱的吸收边斜率，当组分均方差小于0.005时，横向组分波动对透射光谱影响可以忽略．用新的组分分布模型计算了HgCdTe/CdZnTe液相外延薄膜的理论透射光谱，并运用非线性二乘法使理论曲线能够很好地与实验结果吻合，从而获得了更加可信的HgCdTe外延薄膜的纵向组分分布和厚度参数．     

A study of polycrystalline Cd(Zn,Mn)Te/Cds films and interfaces

Polycrystalline films of Cd_1-x Zn _x Te (x = 0–0.4) and Cd_1-x Mn _x Te (x = 0–0.25) were grown by MBE and MOCVD, respectively, on CdS/SnO₂/glass substrates to investigate their feasibility for solar cell applications. The compositional uniformity and interface quality of the films were analyzed by x-ray diffraction, surface photovoltage, and Auger depth profile measurements to establish a correlation between growth conditions and lattice constant, atomic concentration, and bandgap of the ternary films. MBE-grown polycrystalline Cd_1-x Zn _x Te films showed a linear dependence between Zn/(Cd + Zn) beam flux ratio, Zn concentration in the film, and the bandgap. Polycrystalline Cd_1-x Zn _x Te films grown at 300° C showed good compositional uniformity in contrast to compositionally non-uniform Cd_1-x Mn _x Te films grown by MOCVD in the temperature range of 420–450° C. The MBE-grown Cd_1-x Zn _x Te interface also showed significantly less interdiffusion compared to the MOCVD-grown Cd_1-x Mn _x Te/CdS interface, where preferential exchange between Cd from the CdS layer and Mn from the Cd_1-x Mn _x Te film was observed. The compositional uniformity of MOCVD-grown polycrystalline Cd_1-x Mn _x Te films grown on CdS/SnO₂/glass substrates was found to be a strong function of the growth conditions as well as the Mn source.     

近距动态电磁感应装置发射磁场分布的均匀度研究

近距动态电磁感应装置发射磁场的强度和均匀度直接影响收、发系统间信息传递的有效性和稳定性．该文以高射炮引信电磁感应装定系统为平台，依据电磁场理论完成了装备于炮口的有限长疏绕螺旋载流发射线圈内部轴向磁场分布均匀度的理论分析和数值仿真，提出了给定口径和轴向尺寸下轴向磁场分布均匀度较佳的优化结构，并对此进行了实验验证，理论数据与实测结果的良好吻合表明本文设计思想的正确性．文中的设计及实验方法普遍适用于其他电磁感应装置．     

两种微型热管传热性能对比研究

以波形脉动热管和微槽平板热管为研究对象,基于Mixture模型构建了其三维非稳态数学模型,并对模型可靠性进行了验证。采用该数学模型对比了两种微型热管在相同散热空间和散热热流密度情况下的热阻、平均壁面温度和蒸发段壁面温度均匀性。结果表明:相对于微槽平板热管,波形脉动热管热阻更低,传热性能更好;波形脉动热管蒸发段稳态平均壁面温度更低,且随着热流密度的增加该优势更加明显;波形脉动热管在空间尺度上蒸发段壁面温度均匀性更好,且这种优势在高热流密度情况下更突出,但这种均匀性在时间尺度上变化相对剧烈。     

Preparing crystalline silicon from Si-Sn solvent by zone melting directional solidification method

To develop a low cost and highly effective metallurgical route for solar-grade Si production, we investigated the zone melting directional solidification method. In this method, bulk crystalline Si is successfully produced from Si-Sn solvent; this bulk crystalline Si demonstrates a steady growth interface and excellent compositional uniformity. Moreover, the growth rate of bulk crystalline Si along the axial direction increases because the remaining MG-Si serves as Si source to keep the Si-Sn solution saturated with Si atoms, and it is approximately three times larger than that of Si by using the Si-based alloy directional solidification method without Si source. In this work, the evolution of impurity phases segregated in different regions along the axial direction is extensively discussed. The distribution and amount of impurities, including Ca, Al, B, and P, are effectively controlled by this refining method, further improving the quality of bulk crystalline Si.     

Large area depositon of Cd1-xZnxTe on GaAs and Si substrates by metalorganic chemical vapor deposition

Results of large-area (up to 1000 cm²/run) Cd_1-xZn_xTe heteroepitaxy on both GaAs and GaAs/Si substrates by metalorganic chemical vapor deposition (MOCVD) are presented. Cd_1-xZn_xTe (x = 0-0.1) films exhibited specular surface morphology, 1% thickness uniformity (standard deviation), and compositional uniformity (Δx) of ±0.002 over 100 mm diam substrates. For selected substrate orientations and deposition conditions, the only planar defects exhibited by (lll)B Cd_1-xZn_xTe/GaAs/Si films were lamella twins parallel to the CdTe/GaAs interface; these do not propagate through either the Cd_1-xZn_xTe layer or subsequently deposited liquid phase epitaxy (LPE) HgCdTe layer(s). Background Ga and As-impurity levels for Cd_1-xZn_xTe on GaAs/Si substrates were below the secondary ion mass spectroscopy detection limit. Preliminary results of HgCdTe liquid phase epitaxy using a Te-rich melt on Si-based substrates resulted in x-ray rocking curve linewidths as narrow as 72 arc-sec and etch-pit densities in the range 1 to 3 x 10⁶ cm².     

Macro- and microsegregation of Zn in bridgman-grown CdZnTe

One of the remaining problems in the use of CdZnTe material as substrates in liquid phase epitaxy (LPE) of Cd_xHg_1-xTe (CMT) layers is that of variation in lattice matching, i.e. Zn content, across substrates. This wil become increasingly important in the future as larger focal plane arrays of infrared detectors are required. The basic Bridgman growth process for CdTe/Cd_0.96Zn_0.04Te has been extended by applying the accelerated crucible rotation technique (ACRT). A marked reduction in axial Zn segregtion is seen in 50 mm diameter ACRT material, but this effect is smaller in the case of 75 mm diameter crystals. Radial variations in Zn content are small in both sizes of crystal, demonstrating the benefits obtained from ACRT stirring. Both macro- and microsegregation effects have been studied in these crystals in an attempt to understand the growth mechanism. Zinc distributions have been assessed by near-infrared transmission, X-ray lattice parameter measurements, atomic absorption spectrometry (AAS) and Auger electron spectrometry (AES). The last technique was used for the microsegregation studies, while AAS provides the absolute calibration for Zn content. Comparisons with segregation behaviour found in the literature will be given. It will be shown that the low temperature gradient and low growth rate lead to a degree of supercooling in the first-to-freeze region and this leads to significant Zn segregation in both radial and axial directions. As the crystals reach full diameter, the radial variation is decreased, presumably by the action of the ACRT, and axial segregation is also reduced.