n—CdS／p—CulnSe2异质结二极管电流传输机制的研究—计算机模拟分析

应用Ｓｃｈａｒｆｅｔｔｅｒ－Ｇｕｍｍｅｌ解法数值求解电子、空穴连续性方程和泊松方程，对ＣｄＳ／ＣｕＩｎＳｅ２异质结的伏安特性进行计算机数值模拟。基于材料、器件参数的实验数据，我们的计算结果支持了ＣｕＩｎＳｅ２中的Ｓｈｏｃｋｌｅｙ＝Ｒｅａｄ空间电荷复合是控制ＣｄＳ／ＣｕＩｎＳｅ２异质结二极管正向电流主导的物理机制，进一步说明在提高ＣＩＳ太阳电池性能的努力中开展ＣｕＩｎＳｅ２化学缺陷研究的重要性。     

CdS／CdTe－CdS／Cu_2S异质二重结薄膜太阳电池的设计与计算

根据半导体材料的性能参数，考虑光电压Ｖ和耗尽区宽度Ｗ的变化对光电流ＪＬ的影响，较严格地计算了ＣｄＳ／ＣｄＴｅ和ＣｄＳ／Ｃｕ２Ｓ两种异质结单晶薄膜太阳电池的光伏特性曲线。然后在的条件下，对由上述两种异质结构成的二重结太阳电池的ＣｄＴｅ、Ｃｕ２Ｓ厚度进行匹配，计算各种组合下二重结太阳电池的光伏特性曲线。理论证明最佳匹配厚度Ｈｍａｘ约为９．０６μｍ，最大短路电流、开路电压、转换效率分别为１４．２２ｍＡｃｍ－２、１．３Ｖ和１４、６８％。     

蒸发硒化法制备CIS／CdS太阳电池研究

用蒸发硒化法制作的基于ＣｕＩｎＳｅ２（ＣＩＳ）膜的ＣＩＳ／ＣｄＳ太阳电池，面积为０．１ｃｍ２和１ｃｍ２电池的转换效率分别达到７．６２％和７．２８％，５ｃｍ×６ｃｍ电池的平均效率达到６．６７％。对制备工艺及关键技术、电池性能和退火效应进行了分析探讨。     

n－CdS／p－CdTe异质结薄膜太阳电池

ｎ－ＣｄＳ／ｐ－ＣｄＴｅ异质结薄膜太阳电池王万录美国能源部曾在１９８７—１９９１年期间关于光伏研究的五年计划中提出，平板型太阳电池要求达到的主要指标是：转换效率高于１５％，价格每平方米低于１美元，寿命长达２０年。薄膜技术是达到这个目标唯一可行的方法，...     

大面积集成型a－SiC：H／a－Si：H叠层太阳电池的研制

报道了大面积（２７９０ｃｍ２）集成型ａ－ＳｉＣ：Ｈ／ａ－Ｓｉ：Ｈ叠层太阳电池的研制及稳定性实验结果，讨论了限制该电池效率的一些因素。实验电池的性能参数：Ｖｏｃ＝４０．８Ｖ，ＩＳＣ＝５３０．４０ｍＡ，ＦＦ＝４９．４％，有效面积（２２８０ｃｍ２）光电转换效率ＥＦ＝４．６９％（ＡＭ１．５，１００ｍＷｃｍ－２，２５℃）。制备出光电子学性能优良的ａ－ＳｉＣ：Ｈ薄膜及解决电池内部ｎ／Ｐ结的接触问题是提高该电池性能的关键。     

CdIn_2O_4和Cd_2SnO_4薄膜X－光电子能谱研究

研究了在Ａｒ＋Ｏ２混合气氛中从Ｃｄ－Ｉｎ和Ｏｄ－Ｓｎ合金靶射频反应溅射而成的ＣｄＩｎ２Ｏ４和Ｃｄ２ＳｎＯ４膜的Ｘ－光电子能谱。实验结果表明了粉末Ｃｄ、Ｉｎ、Ｓｎ、ＳｎＯ２、Ｉｎ２Ｏ３和ＣｄＩｎ２Ｏ４、Ｃｄ２ＳｎＯ４膜的Ｃｄ、Ｉｎ、Ｓｎ３ｄ３／２和３ｄ５／２ＸＰＳ峰值位置和形状的区别，并讨论了Ｏ１ｓＸＰＳ峰随氧浓度的变化。当氧浓度增加时，Ｏ１ｓ分为两个峰。     

蒸发硒化法制备了CIS／CdS太阳电池研究

用蒸发硒化法制作的基于ＣｕＩｎＳ３２（ＣＩＳ）膜的ＣＩＳ／ＣｄＳ太阳电池，面积为０．１ｃｍ＾２和１ｃｍ＾２电池的转换效率分别达到７．６２＾和７．２８％，５ｃｍ×６ｃｍ电池的平均效率达到６．６７％，对制备工艺及关键技术，电池性能和退火效应进行了分析探讨。     

类 p-i-n 结构 n~ (μc-Si : H)/p(poly-Si)/p~ (poly-Si)薄膜太阳电池的热平衡态特性数值分析

通过应用Ｓｃｈａｒｆｅｔｅｒ－Ｇｕｍｍｅｌ解法，数值求解Ｐｏｉｓｓｏｎ方程，对热平衡态ｎ＋（μｃ－Ｓｉ∶Ｈ）／ｐ（ｐｏｌｙ－Ｓｉ）／ｐ＋（ｐｏｌｙ－Ｓｉ）薄膜太阳电池进行计算机数值模拟。说明类ｐ－ｉ－ｎ结构设计使电池获得了较高的短路电流ＪＳＣ，而中间层ｐ（ｐｏｌｙ－Ｓｉ）的掺杂有利于提高电池的短波量子效率特性，还讨论了ｎ＋（μｃ－Ｓｉ∶Ｈ）和ｐ＋（ｐｏｌｙ－Ｓｉ）等层厚度对光生载流子收集的影响。     

激子和载流子输运的研究：Ⅱ.有机p—n异质结固态太阳电池

在实验工作的基础上，提出双层ｐ－ｎ异质结有机太阳电池中激子和载流子输运的理论模型。假设只有扩散到结区的激子和该区产生的激子，才对形成光电流有贡献。这些激子被有机／有机界面的内建场离解成自由载流子。而后，电子在北红（ｎ型有机半导体）层传导，空穴在酞菁（ｐ型有机半导体）层传导。据此，讨论了双层异质结电池的填充因子和光电转换效率均比单层肖特基型电池获得改善的机制。结合实验分析，认为在北红／酞菁异质结电池中北红（Ｍｅ－ＰＴＣ）层和酞菁（ＣｌＡｌＰｃ）层之间存在Ｆｏｒｓｔｅｒ能量转移。     

SnO_2／p接触特性对a－Si太阳电池填充因子的影响

用ＰＥＣＶＤ方法制备出高电导率（～０．２ｓｃｍ－１）、宽带隙（～２．２ｅＶ）的Ｐ型微晶化硅碳合金（ｐ－μｃ－ＳｉＣ：Ｈ）薄膜材料。利用ｐ－μＣ－ＳｉＣ：Ｈ／ｐ－ａ－Ｓｉ：Ｈ复合结构做ａ－Ｓｉ太阳电池的窗口材料，明显改善了ＳｎＯ２／ｐ之间的接触特性，从而使１０ｃｍ×１０ｃｍ单结集成型电池的填充因子从０．７０以下提高到０．７２。     

Preparation and properties of InAs 50 mol%-CuInSe2 50 mol% alloy

Continuing our search on semiconducting compounds and alloys, the InAs 50 mol%-CuInSe₂ 50 mol% alloy was investigated. Both InAs and CuInSe are adamantine which satisfies the four electron per atom rule. A large single crystal ingot was carefully prepared using the vertical Bridgmans method. The specimen was examined by room temperature and temperature dependence X-ray powder photography, Electron Probe Microanalysis (EPMA), Differential Thermal Analysis (DTA), and Vickers hardness test.     

Study of CuInSe2 thin films prepared by electrodeposition

Thin films of p-type CuInSe₂ prepared by a one-step electrodeposition method have been studied by constructing CdS/CuInSe2 junctions. After the electrodeposition, the CuInSe₂ films were treated either in vacuum or in Ar. Cells of the form CdS (high σ)/CdS (low σ)/CuInSe₂ were then fabricated for studying the electrodeposited films. Measurements were specifically carried out to determine the diffusion length of minority carriers in the p-type CuInSe₂. It was found that the minority carrier diffusion length in CuInSe₂ films treated in Ar was generally greater than that for films treated in vacuum under similar conditions. A small area cell (active area 0.11 cm²) with a conversion efficiency of about 7% (under 125 mW/cm² illumination) has been fabricated.     

Electrodeposition of CuInxGa1−xSe2 thin films

CuIn_xGa_1−xSe₂ (CIGS) polycrystalline thin films with various Ga to In ratios were grown using a new two-step electrodeposition process. This process involves the electrodeposition of a Cu–Ga precursor film onto a molybdenum substrate, followed by the electrodeposition of a Cu–In–Se thin film. The resulting CuGa/CuInSe bilayer is then annealed at 600°C for 60 min in flowing Argon to form a CIGS thin film. The individual precursor films and subsequent CIGS films were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy and Auger electron spectroscopy. The as-deposited precursor films were found to be crystalline with a crystal structure matching that of CuGa₂. The annealed bi-layers were found to have the same basic chalcopyrite structure of CuInSe₂, but with peak shifts due to the Ga incorporation. Energy dispersive spectroscopy results show that the observed shifts correlate to the composition of the films.     

Continuity wave in the elongated bubble region of horizontal slug flow

Visualized observation on the wave feature in a horizontal slug flow was made with a high‐speed digital camera. It was found that the liquid film flow in the elongated bubble region of slug flow behaves as a continuity wave. Theoretical analysis was carried out and it reveals that the liquid film flow is a continuity wave with celerity the same as the translational velocity of the elongated bubble. The control equation for the liquid film height in the elongated bubble region was derived. The results predicted by the equation fit well with the observed data. A new conclusion was obtained that slug flow has continuity wave in it, explaining the stable slug flow wave characterization. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(8): 547–554, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20092     

Immersed boundary computations of shear- and buoyancy-driven flows in complex enclosures

Cartesian grids used with the immersed boundary method (IBM) offer an attractive alternative for simulating fluid flows in complex geometries. We present a ghost fluid method for incompressible flows solved with staggered grids. The primary feature is the satisfaction of local mass continuity for ghost pressure cells, rather than extrapolating the pressures from within the flow domain. The method preserves local continuity in each cell and also global continuity. As a result, no explicit mass sources or sinks are needed. We have applied the method to study shear- and buoyancy-driven flows in a number of complex cavities.     

基于紧凑型光电传感器的复合绝缘子内部缺陷检测方法研究

为了能够有效地对复合绝缘子的内部缺陷进行监测,通过有限元法和现场试验研究了紧凑型光电电场传感器检测复合绝缘子内部缺陷的方法。首先,依据实际110kV复合绝缘子的实际尺寸和材料属性建立了三维有限元模型,导通性缺陷分别设置在复合绝缘子的高压端、接地端和中间端,研究了不同位置和不同程度的导通性缺陷对周围电场分布影响;然后基于有限元仿真计算研究了复合绝缘子周围轴向电场和径向电场分布的变化。结果表明,当复合绝缘子存在内部导通性缺陷时,径向电场分布的变化相对轴向电场分布的变化要更为明显;不同位置的导通性缺陷导致电场分布变化的特征不同;不同严重程度的导通性缺陷导致电场分布的畸变量会随着导通性缺陷的严重程度的增加而增加;最后,通过试验验证了EOEF传感器检测高压复合绝缘子的内部缺陷的有效性。这对于在非固定端检测获取缺陷信息有着重要的意义。     

Reflection and refraction of incident p-, T-, and SV-waves at interface between magnetized two solid-liquid media with heat sources and initial stress with and without thermal relaxation times

We investigate the problem of reflection and refraction of thermoelastic waves at a magnetized solid-liquid interface in presence of initial stress. In the context of Green-Lindsay and coupled thermoelastic theories of thermoelasticity, the problem has been solved and the effect of magnetic field, external heat sources, and initial stress on p-, T-, and SV-waves propagation have been discussed. The boundary conditions at the interface for displacement continuity, vanishing the tangential displacement, continuity of normal force, tangential force, and continuity of temperature are applied. The amplitudes ratios for the incident p-, T-, and SV-waves have been obtained. The effect of the initial stress, heat sources, and magnetic field on the reflection and transmitted coefficients for the incident waves have been discussed.     

Analytic solutions for the mixed convection flow of non-newtonian fluids in parallel plate ducts

The modelling of laminar, fully-developed, combined convection flows of non- Newtonian fluids in a vertical parallel-plate duct, where the walls are held at asymmetric uniform temperatures is considered. For this fully-developed flow model, the momentum, continuity and energy equations are solved analytically for the Bingham Plastic rheology and for the limiting case of Power Law fluids. It is shown that different flow configurations exist depending on the buoyancy parameter, Grashof/Reynolds, which include flow reversal for both rheologies, and unsheared plug flow adjacent to the cold wall for the Bingham Plastic.     

Boiling and spreading of liquid nitrogen and liquid methane on water

An experimental and theoretical investigation was carried out to study the boiling and spreading of liquid nitrogen and liquid methane on water, in a one-dimensional configuration. With the equations of continuity and momentum transfer, a mathematical model was developed to describe the boiling-spreading phenomena of cryogens spilled on water. The model accounts for a decrease in the density of the cryogenic liquid due to bubble formation. Experimental spreading fronts were successfully simulated by assuming constant evaporation rates (40 kW/m² and 92 kW/m² for nitrogen and methane respectively) in the theoretical model. The model predicts the maximum spreading distance and the time for complete vaporization.