Modification of deposition process for Cu(In, Ga)Se2 thin film solar cells on polyimide substrate at low temperature

We fabricate polycrystalline Cu(In, Ga)Se₂ (CIGS) film solar cells on polyimide (PI) substrate at temperature of 450 °C with single-stage process, and obtain a poor crystallization of CIGS films with several secondary phases in it. For improving it further, the two-stage process is adopted instead of the single-stage one. An extra Cu-rich CIGS layer with the thickness from 100 nm to 200 nm is grown on the substrate, and then another Cu-poor CIGS film with thickness of 1.5–2.0 μm is deposited on it. With the modification of the evaporation process, the grain size of absorber layer is increased, and the additional secondary phases almost disappear. Accordingly, the overall device performance is improved, and the conversion efficiency is enhanced by about 20%.     

Fluorescent emission characteristics of polycrystalline diamond film prepared by direct current jet CVD

The free-standing diamond films are deposited on molybdenum substrate by direct current jet chemical vapor deposition （DCJCVD）. X-ray diffraction, Raman spectroscopy and cathodoluminescence （CL） measurement are used to investigate the films structure and defects related to electron transition properties of the diamond films. The X-ray diffraction spectrum reveals that the diamond films have the polycrystalline cubic structure with diffraction peaks at 43.88° and 75.24°. A sharp peak at 1331.8 cm^-1 and a broad band at about 1250-1550 cm^-1 from Raman spectrum are attributed to diamond phase and sp2-type carbons, respectively. Two emission peaks at 440 nm and 530 nm, associated with dislocation defects and nitrogen and vacancy complexes respectively, are observed in cathodoluminescence spectrum. In addition, in order to understand both emission processes, a simple energy level scheme is suggested.     

A1掺杂ZnO薄膜的XPS谱及电学性质研究

采用直流反应磁控溅射法在玻璃基底上用Zn(99.99%)掺杂Al(1.5%)靶制备出高质量的Al掺杂的ZnO(AZO)薄膜.用X射线光电子能谱仪对退火处理后的薄膜进行了成分和元素的价态分析,并用Van der Pauw方法对样品的电学特性进行了测量.实验结果表明,Zn和Al元素都以氧化态的形式存在,O元素主要是以晶格氧和吸附氧的形式存在.AZO薄膜的电学性质受退火温度和氧氩比的影响较大.随着退火温度的升高,电阻率减小,载流子浓度和迁移率增大.随着氧氩比的增大,电阻率增大,迁移率减小.因此可得到用直流反应磁控溅射法制备AZO薄膜的最佳氧氩比和退火温度分别为0.3/27和400 ℃,在此条件下制备出的薄膜电阻率可低至10-4 Ω·cm,载流子浓度可达1020 cm-3.     

基于Pro/E的电火花线切割曲面加工仿真软件开发

阐述了一种用于4轴联动电火花线切割曲面加工的CAD／CAM仿真软件，该软件以Pro／E为开发平台，利用Pro／E自身的二次开发工具TOOLKIT并结合VC＋＋6．0进行二次开发。该仿真软件根据电火花线切割加工的特点，从CAD曲面模型获取加工轨迹点数据，计算出电极丝的位姿，进而生成机床进行曲面加工所需要的NC指令代码，并可在毛坯模型中仿真曲面加工过程。     

光纤化学传感器技术与应用

由于能量和信息处理所涉及的光信号在一种化学惰性和电绝缘的介质－－光纤中传输,光纤化学传感器促进了已广泛应用于化学分析中的化学技术和光谱学方法的发展。本文讨论了光纤化学传感器的探测原理、技术和应用。特别应值得注意的是利用光纤实现远程操作、多点和多方位监测。     

纳米金刚石薄膜的制背

采用微波等离子体化学气相沉积系统,利用氢气、甲烷、氩气和氧气为前驱气体,在直径为5 cm的(111)取向镜面抛光硅衬底上沉积出高平整度纳米金刚石薄膜.利用扫描电镜、X射线衍射谱和共焦显微显微拉曼光谱我们分析了薄膜的表面形貌和结构特征.该薄膜平均粒径约为20 nm.X射线衍射谱分析表明该薄膜具有立方相对称 (111)择优取向金刚石结构.在该薄膜一阶微显微拉曼光谱中,1 332 cm-1附近微晶金刚石的一阶特征拉曼峰减弱消失,可明显观测到的三个拉曼散射峰分别位于1 147 cm-1、1 364 cm-1和1 538 cm-1,与己报导的纳米金刚石拉曼光谱类似.该方法可制备出粒径约为20 nm粒度分布均匀致密具有较高含量的sp3键的纳米金刚石薄膜.     

Test method of frequency response based on diamond surface acoustic wave devices

In order to reduce the noises affixed to the signals when testing high frequency devices,a single-port test mode(S11) is used to test frequency response of high frequency(GHz) and dual-port surface acoustic wave devices(SAWDs) in this paper.The feasibility of the test is proved by simulating the Fabry-perot model.The frequency response of the high-frequency dual-port resonant-type diamond SAWD is measured by S11 and the dual-port test mode(S21),respectively.The results show that the quality factor of the device is 51.29 and the 3 dB bandwidth is 27.8 MHz by S11-mode measurement,which is better than the S21 mode,and is consistent with the frequency response curve by simulation.     

光学信息处理的应用

本文叙述了我实验室在光学信息处理研究中部分应用成果 ,着重在阻尼Projection无模式算法用于粒度分布反演 ,以及数学形态学尺度—空间变换用于动态目标的跟踪等。同时给出了实验结果。     

Synthesis and photoluminescent properties of ZnO:Cu/ZnO core/shell nanocrystals

ZnO:Cu/ZnO core/shell nanocrystals are synthesized by a two-step solution-phase process. The morphology, structure and optical properties of the samples are detected by scanning electron microscopy, Raman, absorption and luminescence spectroscopy. The increase of particle size confirms the growth of ZnO shell. The segregation of CuO phase observed in ZnO: Cu core is not detected in ZnO:Cu/ZnO core/shell nanocrystals from Raman spectra. It is suggested that some Cu ions can be segregated from ZnO nanocrystals, and the separated Cu ions can be incorporated inside ZnO shell after the growth of ZnO shell. The visible emission mechanism is discussed in detail, and the photoluminescence analysis indicates that the core/shell structure helps to eliminate the surface-related emission.     

线路调爬对变电设备绝缘配合的影响

论述了输电线路调爬的必要性和配电装置绝缘配合的一般原则。通过对影响避雷器运行工况的雷电幅值ＩＢＬ和来波陡度α的分析计算，说明了线路调爬后耐雷水平的增加对变电设备绝缘配合的影响。