太阳电池中新腐蚀液实现纳米黑硅表面的一步腐蚀制备

通过引入添加剂,调节腐蚀溶液的pH值,实现了一步法制备黑硅表面. 在取得低表面反射率的同时,减小了黑硅层的腐蚀深度,对于16 min腐蚀的黑硅层,其表面加权平均反射率可达5%(300～1200 nm),但腐蚀深仅约为200 nm. 减小腐蚀深度能够降低黑硅太阳电池的表面复合速率,从而提高太阳电池性能,尤其是开路电压及填充因子. 以新腐蚀液制备的黑硅为衬底,在常规太阳电池产线上制备大面积p-Si黑硅太阳电池,实现了15.63%的转换效率,具有高的开路电压(624.32 mV)和填充因子(77.88%),改进了大面积黑硅太阳电池的性能.     

多层介质中的光自旋霍尔效应研究

本文研究了光束通过多层介质分界面的光自旋霍尔效应. 以三层介质为例,建立了光束通过棱镜-空气-棱镜结构的传输模型,揭示了横移与空气介质的厚度、折射率梯度以及入射角等因素的定性关系. 发现对某一特定的圆偏振光束,改变两棱镜之间的折射率梯度可以调控横移,反射场与传输场的横移方向取决于折射率梯度. 相对于两层介质来说,高斯光束通过三层介质能明显地增强光自旋霍尔效应. 研究多层介质中光自旋霍尔效应横移的影响因素可为调控和增强光自旋霍尔效应提供理论依据. 关键词： 光自旋霍尔效应 横移 折射率梯度     

p型纳米硅与a-Si∶H不锈钢底衬nip太阳电池

报道了选用厚度为0.05mm的不锈钢箔作衬底,B掺杂P型氢化纳米硅作窗口层,制备成功开路电压和填充因子分别达到0.90V和0.70的nip非晶硅基薄膜单结太阳电池.UV VIS透射谱和微区Raman谱证实所用p层具有典型氢化纳米硅的宽能隙和含有硅结晶颗粒的微结构特征.明确指出导致这种氢化纳米硅能隙展宽的物理机制是量子尺寸效应.     

一维缺陷光子晶体温度的测量

采用Si和SiO₂两种介质材料构造一维缺陷光子晶体,缺陷层介质为Si,利用传输矩阵法对带有缺陷的一维光子晶体的传光特性进行了理论分析,并得到其带隙特性.由于缺陷的存在,使得光子晶体的透射谱中产生缺陷峰.当被测温度变化时,根据两种介质的热光效应和热膨胀效应,光子晶体介质和缺陷层的光学厚度和折射率发生变化,透射谱缺陷峰产生漂移,由缺陷峰的中心波长漂移量得到被测温度的大小.构建了一维缺陷光子晶体测量温度的实验系统,实验结果表明缺陷峰中心波长与光子晶体所受的温度呈线性关系,测量灵敏度为0—2 关键词： 温度测量 一维光子晶体 传输矩阵法 缺陷峰     

高k栅介质对肖特基源漏超薄体SOI MOSFET性能的影响

研究了高k栅介质对肖特基源漏超薄体SOI MOSFET性能的影响.随着栅介质介电常数增大,肖特基源漏(SBSD) SOI MOSFET的开态电流减小,这表明边缘感应势垒降低效应(FIBL)并不是对势垒产生影响的主要机理.源端附近边缘感应势垒屏蔽效应(FIBS)是SBSD SOI MOSFET开态电流减小的主要原因.同时还发现,源漏与栅是否对准,高k栅介质对器件性能的影响也不相同.如果源漏与栅交叠,高k栅介质与硅衬底之间加入过渡层可以有效地抑制FIBS效应.如果源漏偏离栅,采用高k侧墙并结合堆叠栅结构,可以提高驱动电流.分析结果表明,来自栅极的电力线在介电常数不同的材料界面发生两次折射.根据结构参数的不同可以调节电力线的疏密,从而达到改变势垒高度,调节驱动电流的目的. 关键词： k栅介质')" href="#">高k栅介质 肖特基源漏(SBSD) 边缘感应势垒屏蔽(FIBS) 绝缘衬底上的硅(SOI)     

填充多层互易手征介质金属同轴线传播特性

 采用在圆柱坐标系中分离变量的方法，推出填充多层互易手征介质的金属同轴线各层电磁场之间的关系，得到其模式特征方程和圆波导模式特征方程，给出了填充两层手征介质金属同轴线部分模式的色散特性的数值计算结果，分析了手征介质参量及两层手征介质厚度变化等对手征同轴线传播特性的影响。如果互易手征介质的手征参数等于零，可得填充普通介质的同轴线的模式特征方程。与填充普通介质的同轴线中的模式相比，手征同轴线中的模式发生了分叉。当同轴线中所填介质的折射率增大时，其模式归一化截止频率和进行基模单模传输的带宽归一化频率都将减小。     

考虑通孔和边缘效应的互连网络热电分析

考虑互连通孔和边缘效应,建立互连层间、层内、通孔热阻模型,利用热电二元性,提出一种考虑温度效应对热流影响的热电耦合仿真方法,利用热电之间的反馈关系,修正建模后的温度分布对节点网络热流的影响.并对以聚合物和硅氧化物为介质的多层互连进行分析,以有限元建模结果为参照,与已有模型相比,互连热分布结果的相对标准差分别降低了71.2%、12.9%.考虑通孔效应和边缘效应后,该方法在不同纳米级工艺中所得峰值温升,较已有模型均有一定程度的降低.     

材料的吸收效应对光子晶体温感特性的影响

利用传输矩阵法对含有缺陷层光子晶体缺陷模的透射率进行计算,主要讨论了材料的吸收效应对光子晶体温感特性的影响。以波长为800nm处缺陷态的透射峰作为研究对象,通过MATLAB数学软件数值模拟仿真发现:随着温度逐渐增加,缺陷模的透射率随之减小,说明光子晶体对温度变化有一定的灵敏度;介质材料的吸收效应会使透射峰随温度变化的速度减小,即光子晶体的缺陷模对温度变化的灵敏度减小;介质材料的消光系数越大,光子晶体的缺陷模对温度变化的灵敏度则越小。     

光谱法研究灿烂甲酚蓝与DNA的相互作用

利用紫外-可见(UV/Vis)光谱法研究了小分子染料灿烂甲酚蓝(BCB)与小牛胸腺DNA(ct DNA)的相互作用。实验表明,DNA在低浓度时,BCB能结合DNA形成1∶1的化合物,结合常数为4.3×104 L·mol-1,DNA与BCB的主要结合方式是“静电作用”方式;而在较高浓度时,则变成“嵌入作用”方式。为了进一步证明BCB分子嵌入到DNA, 利用了羟丙基-β环糊精(HP-β-CD)与BCB的包合行为来研究。实验证明,BCB分子能进入HP-β-CD的疏水性空腔形成包合物, 稳定常数为1.98×103 L·mol-1;高浓度DNA存在时,BCB分子从HP-β-CD空腔中离解而与DNA发生嵌入作用。据此可推断出BCB分子能嵌入到DNA的双螺旋沟槽中。BCB分子属经典的嵌入剂。     

p型纳米硅与a-Si：H不锈钢底衬nip太阳电池

报道了选用厚度为0．05mm的不锈钢箔作衬底，B掺杂P型氢化纳米硅作窗口层，制备成功开路电压和填充因子分别达到0．90V和0．70的nip非晶硅基薄膜单结太阳电池．UV-VIS透射谱和微区Raman谱证实所用p层具有典型氢化纳米硅的宽能隙和含有硅结晶颗粒的微结构特征．明确指出导致这种氢化纳米硅能隙展宽的物理机制是量子尺寸效应．     

基于散射矩阵法的飞机壁板声学优化设计

采用散射矩阵法分析夹层板结构声学特性,并对典型的夹层板结构即飞机壁板进行声学优化,预计飞机壁板隔声特性,获得蒙皮、隔声隔热层、内饰板及它们的组合结构的声学性能。针对尾吊飞机客舱后部噪声过大问题,通过增加铺设隔热隔声层以及部分区域优化安装阻尼层等一系列被动降噪处理方法,对主要传递路径的飞机壁板结构进行优化,降低客舱后部噪声水平,并进行试验验证。试验结果表明:散射矩阵法可快速准确获得夹层结构的隔声性能,并与混响室法测试结果吻合较好;在厚度不变的前提下,改变隔热隔声层的铺设方式和材料密度对壁板隔声性能影响较小,但在蒙皮内侧粘贴阻尼层能在一定频段范围提高壁板隔声性能;将优化的壁板构型应用到飞机后舱段侧壁板,舱内噪声水平可降低约3 dB。     

基于(火积)理论的轧钢加热炉壁变截面绝热层构形优化

基于绝热过程(火积)耗散极值原理, 分别在对流传热和复合传热(对流和辐射传热)边界条件下, 对轧钢加热炉壁变截面绝热层进行构形优化, 得到(火积)耗散率最小的绝热层最优构形. 结果表明: 与等截面绝热层相比, (火积)耗散率最小的变截面绝热层整体绝热性能更优. 热损失率最小和(火积)耗散率最小的绝热层最优构形是不同的. 热损失率最小的绝热层最优构形使得其能量损失减小, 而(火积)耗散率最小的绝热层最优构形使得其整体绝热性能提高. (火积)耗散率最小和最大温度梯度最小的变截面绝热层最优构形差别较小, 此时(火积)耗散率最小的绝热层最优构形在提高绝热层整体绝热性能的同时也提高了其热安全性. 基于(火积)理论的绝热层构形优化为绝热系统的优化设计提供了新的指导.     

Electrochemical deposition of cerium on porous silicon to improve photoluminescence properties

In this work, we present results for Cerium (Ce) doping effects on photoluminescence (PL) properties of porous silicon (PS). Cerium was deposited using electrochemical deposition on porous silicon prepared by electrochemical anodization of P-type (100) Si. From the photoluminescence spectroscopy, it was shown that porous silicon treated with cerium can lead to an increase of photoluminescence when they are irradiated by light compared to the porous silicon layer without cerium. In order to understand the contribution of cerium to the enhanced photoluminescence, energy dispersive X-ray (EDX) spectroscopy, Fourier transmission infrared spectroscopy (FTIR), X-ray diffraction (XRD) and atomic force microscopy (AFM) were performed, and it was shown that the improved photoluminescence may be attributed to the change of Si–H bonds into Si–O–Ce bonds and to a newly formed PS layer during electrochemical Ce coating.     

Investigation of silicon-on-sapphire structures by means of TEM

The initial stages of the molecular beam epitaxy (MBE) growth of silicon-on-sapphire (SOS) are investigated via transmission electron microscopy (TEM). The sample preparation procedure is improved to study SOS structures by TEM. It is shown that silicon in the shape of 3D islets can form on a continuous silicon layer grown on sapphire.     

钢结构装配式住宅墙板连接方式对隔声性能的影响

为提升钢结构装配式住宅隔声性能,通过有限元法数值分析,比较了不同位置墙板的连接方式对房间隔声性能的影响.结果表明:侧墙墙板柔性连接处理对侧向传声的抑制作用显著,当侧墙墙板采用柔性连接后,房间的隔声量在低频段平均可以提升3 dB左右;公共隔墙墙板的柔性连接对房间低频段隔声量提升不明显,甚至在160 Hz、400 Hz、5...     

碳纳米管封装Si20团簇的热稳定性研究

用分子动力学方法模拟一种特殊结构Si20 (表面异构的硅十二面体结构)填充到不同管径的扶手椅型碳纳米管中组成复合结构的热稳定性。通过能量分析和定量统计缺陷多边形数量等方法来研究这种结构在碳纳米管中的稳定性和结构演变情况。研究发现Si20的热稳定性和碳纳米管的直径关系密切;其在CNT(15, 15)中的热稳定性最好,当管径逐渐增加时,其热稳定性呈下降趋势;直至管径增加到CNT(21, 21),碳纳米管对Si20的空间限制作用变得很小,以至于不足以维持Si20的稳定。此外,Si原子因热振动替换碳纳米管中C原子而形成十二边形缺陷,这对碳纳米管的热稳定性有着明显的降低作用。     

Dual material insulator SOI-LDMOSFET: A novel device for self-heating effect improvement

The silicon-on-insulator (SOI) power devices show good electrical performance but they suffer from inherent self-heating effect (SHE), which limits their operation at high current levels. The SHE effect is because of low thermal conductivity of the buried oxide layer. In this paper we propose a novel silicon on insulator lateral double diffused MOSFET (SOI-LDMOSFET) where the buried insulator layer under the active region consists of two materials in order to decrease the SHE. The proposed structure is called dual material buried insulator SOI-LDMOSFET (DM-SOI). Using two-dimensional and two-carrier device simulation, we demonstrate that the heat dissipation and the SHE can be improved in a conventional SOI-LDMOSFET by replacement of the buried oxide with dual material buried insulator (silicon nitride and silicon oxide) beneath the active region. The heat generated in the active silicon layer can be flowed through the buried silicon nitride layer to the silicon substrate easily due to high thermal conductivity of silicon nitride. Furthermore, the channel temperature is reduced, negative drain current slope is mitigated and electron and hole mobility is increased during high-temperature operation. The simulated results show that silicon nitride is a suitable alternative to silicon dioxide as a buried insulator in SOI structures, and has better performance in high temperature.     

Influence of oxygen on the growth of carbon nanotubes by the SiC surface decomposition method

The influence of oxygen on the development of carbon nanotubes (CNTs) during the annealing process of the surface decomposition method on SiC(000−1) surfaces was investigated. In the case of annealing a SiC substrate under ultra-high vacuum conditions, carbon nanofibers (CNFs) form between the CNT layer and the substrate. However, CNTs form without CNFs by annealing the substrate in an oxygen atmosphere. The mean length of CNTs is longer than those formed without an oxygen atmosphere. From cross-sectional transmission electron microscopy images, it was found that oxygen plays an important role in CNT growth by the surface composition method.     

Effect of Clay Addition on the Properties of Carbon Nanotubes-Filled Immiscible Polyethylene/Polypropylene Blends

The effects of organically modified clay (OMC) incorporation on the microstructure and the electrical and mechanical properties of polypropylene (PP)/polyethylene (PE) blends filled with carbon nanotubes (CNT) were investigated. All blends were prepared by melt mixing in a batch mixer. The microstructures were characterized by scanning electron microscopy. In the OMC:CNT filled blends, the CNT were found to selectively localize within the PE phase, while the clay particles were observed in the PP phase. The electrical resistivity of OMC:CNT filled blends did not show any significant change as a result of the clay addition since it was localized in the CNT-free phase. On the other hand, the addition of clay degraded the blends' mechanical properties due to the poor adhesion between the OMC and the PP matrix.     

改进RCF算法的电缆绝缘层边缘检测

目前电缆绝缘层厚度检测算法主要采用图像处理技术提取出绝缘层的边缘轮廓,此类算法存在绝缘层边缘过宽和边缘不连续等问题,影响了后续的检测精度.为提高绝缘层测量精度,新算法基于RCF算法进行改进,在模型的4、5阶段采用空洞卷积,增大模型的感受野;并在侧输出网络加入尺度增强模块(SEM模块)和由浅到深的级联网络,增加侧输出图像...