基于数值模拟的CZSi单晶收尾控制参数研究

采用理论分析和有限元数值模拟相结合的方法研究了晶体收尾过程中的温度分布与热量传递.解释了"倒草帽"形收尾(收尾前段晶体直径猛然收缩)的成因,指出了改进收尾形状的方法,研究结果对于合理设定直拉硅单晶收尾工艺参数具有一定的参考意义.通过对比试验,仿真计算结果与单晶炉实验测试结果相吻合.     

MOCVD方法在Ti/Si(111)模板上生长ZnO薄膜的研究

本文采用常压MOCVD方法在Ti/Si（111）模板上生长了氧化锌（ZnO）薄膜,使用二乙基锌为Zn源,去离子水为O源。Si衬底上的Ti薄层采用电子束蒸发台蒸发,然后低温生长缓冲层并在高温下进行重结晶,接着在680％进行ZnO薄膜的生长。采用粉末衍射法、双晶X射线衍射及光致发光技术研究了材料的取向、结晶性能及发光性能。结果表明,本文制备了高度择优取向和良好发光性能的ZnO薄膜。     

Resistivity distribution of silicon single crystals using codoping

Numerous studies including continuous Czochralski method and double crucible technique have been reported on the control of macroscopic axial resistivity distribution in bulk crystal growth. The simple codoping method for improving the productivity of silicon single-crystal growth by controlling axial specific resistivity distribution was proposed by Wang [Jpn. J. Appl. Phys. 43 (2004) 4079]. Wang [J. Crystal Growth 275 (2005) e73] demonstrated using numerical analysis and by experimental results that the axial specific resistivity distribution can be modified in melt growth of silicon crystals and relatively uniform profile is possible by B–P codoping method. In this work, the basic characteristic of 8 in silicon single crystal grown using codoping method is studied and whether proposed method has advantage for the silicon crystal growth is discussed.     

CrO2 (1 0 0) and TiO2 (1 0 0) film heteroepitaxy on a BaF2 (1 1 1)/Si (1 0 0) substrate

Multi-domained heteroepitaxial rutile-phase TiO₂ (1 0 0)-oriented films were grown on Si (1 0 0) substrates by using a 30-nm-thick BaF₂ (1 1 1) buffer layer at the TiO₂–Si interface. The 50 nm TiO₂ films were grown by electron cyclotron resonance oxygen plasma-assisted electron beam evaporation of a titanium source, and the growth temperature was varied from 300 to 600 °C. At an optimal temperature of 500 °C, X-ray diffraction measurements show that rutile phase TiO₂ films are produced. Pole figure analysis indicates that the TiO₂ layer follows the symmetry of the BaF₂ surface mesh, and consists of six (1 0 0)-oriented domains separated by 30° in-plane rotations about the TiO₂ [1 0 0] axis. The in-plane alignment between the TiO₂ and BaF₂ films is oriented as [0 0 1] TiO₂ || BaF₂ or [0 0 1] TiO₂ || BaF₂ . Rocking curve and STM analyses suggest that the TiO₂ films are more finely grained than the BaF₂ film. STM imaging also reveals that the TiO₂ surface has morphological features consistent with the BaF₂ surface mesh symmetry. One of the optimally grown TiO₂ (1 0 0) films was used to template a CrO₂ (1 0 0) film which was grown via chemical vapor deposition. Point contact Andreev reflection measurements indicate that the CrO₂ film was approximately 70% spin polarized.     

硅基槽式微环谐振腔型偏振解复用器全矢量分析

提出一种紧凑型偏振解复用器, 其中两条常规硅基波导作为输入/输出信号通道, 居于其中的槽式微环谐振腔用于偏振态/波长选择组件. 采用全矢量频域有限差分法详细分析了硅基常规及槽波导的模式特性, 结果发现其横磁模的模场布及其有效折射率相似, 而其横电模相应的特性则差异明显, 结果输入横磁模能够在谐振工作波长下从下路端口输出, 而输入横电模与微环耦合可以忽略, 直接从直通端口输出, 从而实现两偏振态的高效分离. 采用全矢量时域有限差分法详细分析了该偏振解复用器的光波传输特性, 结果表明, 当微环半径为3.489 μm时, 在1.55 μm工作波长下, 横磁模与横电模的消光比与插入损耗分别为 ～ 26.12 (36.67) dB与 ～ 0.49 (0.09) dB. 另外, 论文详细讨论了器件关键结构参数的制作容差, 并给出了输入模场在器件中的传输演变情况.     

Crystalline silicon solar cells with high resistivity emitter

The paper presents a part of research targeted at the modification of crystalline silicon solar cell production using screen-printing technology. The proposed process is based on diffusion from POCl₃ resulting in emitter with a sheet resistance on the level of 70 Ω/□ and then, shaped by high temperature passivation treatment. The study was focused on a shallow emitter of high resistivity and on its influence on output electrical parameters of a solar cell. Secondary ion mass spectrometry (SIMS) has been employed for appropriate distinguishing the total donor doped profile. The solar cell parameters were characterized by current-voltage characteristics and spectral response (SR) methods. Some aspects playing a role in suitable manufacturing process were discussed. The situation in a photovoltaic industry with emphasis on silicon supply and current prices of solar cells, modules and photovoltaic (PV) systems are described. The economic and quantitative estimation of the PV world market is shortly discussed.     

溶液法铝诱导晶化制备多晶硅薄膜

采用铝（Al）盐溶液作为诱导源进行了非晶硅晶化成多晶硅的研究.光学显微镜观测与Raman光谱分析表明,合适配比的铝盐溶液能够将非晶硅予以诱导晶化.采用剥层XPS测试分析,探究了Al盐溶液与硅表面可能的化学反应以及随之发生的硅-铝层交换的过程.最后对溶液法诱导晶化的机理进行了讨论. 关键词： 铝诱导晶化 多晶硅薄膜 溶液法     

Effect of high-pressure water-vapor annealing on energy transfer in dye-impregnated porous silicon

We have studied the effect of high-pressure water-vapor annealing (HWA) on the excitation energy transfer from Si nanocrystals to dye molecules in porous Si layers. Efficient photoluminescence, originating from both RhB molecules and Si nanocrystals, was observed. The behavior of the polarization memory of the photoluminescence showed the presence of energy transfer from the surface-passivated Si nanocrystals to RhB molecules. The fact that HWA, which is an effective method to stabilize and enhance the emission from Si nanocrystals in porous Si, does not suppress the energy transfer is an important result since it makes possible the realization of stable Si/dye-nanocomposite functional devices.     

基于多层叉指超微带电极阵列的葡萄糖传感器

采用多层工艺和光刻方法在玻璃衬底上加工了亚微米级金叉指型超微带电极阵列（IDA）,IDA电极的宽度为362nm,电极表面位于沟槽内。实验表明,所加工的IDA电极可作为生物和化学传感器的一次性超微基体电极。采用电聚合的方法将葡萄糖氧化酶（GOD）和吡咯（PPy）固定于IDA电极,该修饰电极可作为葡萄糖传感器。采用该葡萄糖传感器对磷酸钾缓冲溶液（pH7．0）中的葡萄糖浓度进行了比对测量,在2．0-7．0mmol／L的浓度范围内,传感器的响应时间为10s;灵敏度为14．6nA／（mmol／L）,相关系数为0．999。