突变异质结双极晶体管中的复合效应与电流传输

建立了带有不掺杂隔离层的突变异质结双极晶体管（ＨＢＴ）模型，在热场发射－扩散（ＴＦＤ）理论的基础上，又考虑了空间电荷区中的复合效应。对ＡｌＧａＡｓ／ＧａＡｓＨＢＴ特性的分析表明，不掺杂隔离层虽可有效地降低导带边的势垒尖峰，提高发射结的注入效率，但也会增大空间电荷区中的复合电流。因此，在实际器件的设计和制作中，应适当选择不掺杂隔离层的厚度，以获得较好的器件特性。还给出了计算突变异质结界面处电子准费米能级不连续的公式。     

Pinning of the Fermi Level in CuFeO2 by Polaron Formation Limiting the Photovoltage for Photochemical Water Splitting

CuFeO₂ is recognized as a potential photocathode for photo(electro)chemical water splitting. However, photocurrents with CuFeO₂‐based systems are rather low so far. In order to optimize charge carrier separation and water reduction kinetics, defined CuFeO₂/Pt, CuFeO₂/Ag, and CuFeO₂/NiO_x(OH)_y heterostructures are made in this work through a photodeposition procedure based on a 2H CuFeO₂ hexagonal nanoplatelet shaped powder. However, water splitting performance tests in a closed batch photoreactor show that these heterostructured powders exhibit limited water reduction efficiencies. To test whether Fermi level pinning intrinsically limits the water reduction capacity of CuFeO₂, the Fermi level tunability in CuFeO₂ is evaluated by creating CuFeO₂/ITO and CuFeO₂/H₂O interfaces and analyzing the electronic and chemical properties of the interfaces through photoelectron spectroscopy. The results indicate that Fermi level pinning at the Fe³⁺/Fe²⁺ electron polaron formation level may intrinsically prohibit CuFeO₂ from acquiring enough photovoltage to reach the water reduction potential. This result is complemented with density functional theory calculations as well.     

分束李普奇棱镜与分束汤普逊棱镜性能的比较分析

为了更好地设计和选择使用分束李普奇棱镜和分束格兰•汤普逊棱镜,本文从理论上分析了分束李普奇棱镜与分束格兰•汤普逊棱镜的分束角、分离角和光强分束比。结果表明：分束李普奇棱镜和分束格兰•汤普逊棱镜的分束角和光强分束比与棱镜的结构角和副结构角有关;对于相同的结构角和副结构角,两种棱镜的分束角相同,但它们的光强分束比不同。出射的 光与 光的分离角与副结构角有关;对于 光垂直出射的需要,选用分束李普奇棱镜设计为好;对于大分束角的需要,选用分束格兰•汤普逊棱镜设计为好。     

分光比规格偏差对节点电平及其均衡性的影响

分析了规格型光分路器分光比规格值与网络设计值（实际需要值）的偏差对光节点电平及其均衡性的影响,指出了通常按分光比等量均匀递变划定和设计的光二分路器规格体系存在的问题,给出了一种按分光比非等量递变划定和设计光二分路器规格的思路、方法和规格表。提出分光比规格值与设计值的偏差对光节点电平及其均衡性的影响主要表现在分光比较低的光路上,因而在设计规格和选择型号时,只需要考虑分光比低端适用范围。只要低端分光比偏差在允许范围内,对光节点电平及其均衡性的影响就必定在正常范围内。     

随机误差对阵列天线副瓣电平的影响分析

采用三角函数近似和幂级数展开近似等数值方法,推导出阵列天线中的阵元随机误差(包括幅度误差和相位误差)对天线副瓣电平产生影响的一般规律,代替难以得到的解析解。分析结果表明:随机误差对副瓣电平的影响与阵元数目和阵元幅值分布有关,而且不同的随机误差近似计算方法得到的结果亦有所不同,在不存在解析解的条件下,只有综合比较各种方法,才能客观估计随机误差对天线副瓣性能的影响。     

光致发光发热光分频利用光纤研究

该文利用光热转换六硼化镧（LaB6）、加拿大树脂、纳米SiO2,制备了不同掺杂含量的LaB6-SiO-加拿大树脂溶胶,并涂敷在塑料光纤表面,构成了光致发光发热光分频利用光纤。测试了LaB6颗粒的吸收光谱及升温速率,LaB6掺杂含量与涂敷层厚度对光纤表面发光发热性能的影响。LaB6在波长为510~650 nm时出现弱吸收,用于光辐射;LaB6对其他可见 近红外波段的光呈现出强吸收,用于产热。当LaB6的质量分数为0.30%,涂敷层厚为200 μm时,光纤表面发光发热的均匀性最佳,观测点的平均发光强度及平均升温速率分别达到26.59 μW/cm2和0.29 ℃/min,实现了可见 近红外光谱的光分频利用。     

红宝石激光晶体零场分裂及其光谱精细结构研究

推导了ｄ＾３（Ｃ＾＊３ｖ）组态离子的中间场能量矩阵，建立了红宝石（Ｃｒ＾３＋：Ａｌ２Ｏ３）晶体基态＾４Ａ２零场分裂（ＺＦＳ）参量Ｄ及＾２Ｅ态分裂△Ｅ（＾２Ｅ）与晶体结构之间的定量关系；假设晶格畸变的基础上，统一地计算了Ｃｒ＾３＋：Ａｌ２Ｏ３晶体的ＺＦＳ参量Ｄ、Ｚｅｅｍａｎｇ因子、精细光谱及＾２Ｅ态的分裂△Ｅ（＾２Ｅ），计算结果与实验观测十分吻合，定量的研究结果表明：当Ｃｒ＾３＋离子掺入Ａｌ２Ｏ３晶     

鳃、钙离子复合激光激励电路的分析

对Sr^ 、Ca^ 复合激光所用的Blumlein电路的放电过程和脉冲波形进行了计算机模型。在相同电路参数时,经模拟得到的放电管电流脉冲波形和实测的波形相一致。给出了该电路中各元件上放电脉冲波形间的时间关系,明确了放电过程的先后次序以及对应放电管的击穿电压和时刻。计算和比较了不同电路参数组合时流过放电管的电流脉冲波形,按照复合激光对放电电流脉冲后沿的要求,获得了一组较佳的电路参数。     

In Situ Scanning Electron Microscopy Observation of Growth Kinetics and Catalyst Splitting in Vapor–Liquid–Solid Growth of Nanowires

In situ observations during vapor–liquid–solid (VLS) growth of semiconductor nanowires in the chamber of an environmental scanning electron microscope (ESEM) are reported. For nanowire growth, a powder mixture of CdS and ZnS is used as a source material and silver nanoparticles as a metal catalyst. Through tracing growth kinetics of nanowires, it is found that nanowires with a relatively bigger catalyst droplet on the tip grow faster. Intriguingly, it is also found that the growth of nanowires can involve catalyst splitting: while the majority of catalyst remains at the nanowire tip and continues facilitating the growth, a portion of it is removed from the tip due to the splitting. It remains attached to the nanowire at the position where the splitting occurred and subsequently induces the growth of a nanowire branch. As far as it is known, this is the first time that catalyst splitting is revealed experimentally in situ. It is proposed that the instability of catalyst droplet caused by the volume increase is the main reason for the splitting. It is believed that in situ growth inside the ESEM can largely enrich our understanding on the metal‐catalyzed VLS growth kinetics, which may open up more opportunities for morphology‐controlled synthesis of 1D semiconductor nanowires in future study.     

有机磷光电致发光器件中的复合宽度和外量子效率

从经验公式出发,基于T-T湮灭过程,建立了有机磷光电致发光器件中复合宽度和外量子效率的理论模型.结果表明:(1)随外加电压升高,器件的复合宽度减小,外量子效率增加;(2)随器件厚度的增加,复合宽度相应增加,但外量子效率在不同的电压下呈现不同的变化趋势;(3)外量子效率随复合电流密度的增大而显著降低.讨论了外加电压和器件厚度对复合宽度的影响,分析了外量子效率随外加电压、器件厚度及复合电流密度变化的原因.     

异质结耗尽层基区侧复合对突变HBT重要性分析

基于热场发射.扩散载流子输运模型,在电流连续性方程中包含异质结(BB结)耗尽层基区侧复合电流的前提下,推导出了描述突变HBT电流特性的新解析方程.在此基础上,探讨了对BB结耗尽层基区侧复合电流各不同考虑情况下的HBT电流计算结果的差异程度.结果表明:在较高集电极电流密度处,E-B结耗尽层基区侧的复合电流很重要;此外,在电流连续性方程中包含E-B结耗尽层基区侧的复合电流,这在更高集电极电流密度处也是必要的.