TCO镀膜玻璃生产线控制系统设计及模块化编程实践

TCO镀膜玻璃是薄膜太阳能电池的重要组成元件,本文详述了我国第一条投入商用的TCO镀膜玻璃生产线控制系统设计过程。简要介绍了采用罗克韦尔自动化最新EthernetIP DLR网络技术的系统结构及其高速率、高可靠性、高扩展性、简单易用等特点。重点介绍了罗克韦尔自动化模块化编程技术在控制系统编程设计实施中基于控制对象的数据封装、模块划分及彼此间关系定义、接口实现和AOI用户自定义程序块的封装等过程。体现出模块化编程相对于传统编程方式给OEM客户所带来的快速创新能力的优势。     

Effect of aluminum and indium co-doping on zinc oxide films prepared by dc magnetron sputtering

Aluminum and indium co-doped zinc oxide (AIZO) thin films were prepared by direct current (dc) magnetron sputtering on glass substrate in pure argon atmosphere. Three inches of zinc oxide ceramic with 0.5 wt.% of aluminum and indium doping was used as a target in static mode. The influence of sputtering conditions i.e. substrate-target distance, pressure and power on AIZO films was studied. The electrical resistivity and microstructure of thin films were investigated by the four point probe technique and the scanning electron microscope, respectively. The optical transmittance of AIZO films was measured by UV visible spectrophotometer in the wavelength of 300-1100 nm. Depending on the deposited conditions, highly transparent films up to 80% with low resistivities in the range of 2.6-7.9 × 10^− 4 Ω cm were achieved at room temperature. Possible mechanism in the processing which, ultimately, determines the physical properties of AIZO films will be discussed.     

Improving low pressure chemical vapor deposited zinc oxide contacts for thin film silicon solar cells by using rough glass substrates

Compared to zinc oxide grown (ZnO) on flat glass, rough etched glass substrates decrease the sheet resistance (R_sq) of zinc oxide layers grown on it. We explain this R_sq reduction from a higher thickness and an improved electron mobility for ZnO layers deposited on rough etched glass substrates. When using this etched glass substrate, we also obtain a large variety of surface texture by changing the thickness of the ZnO layer grown on it. This new combination of etched glass and ZnO layer shows improved light trapping potential compared to ZnO films grown on flat glass. With this new approach, Micromorph thin film silicon tandem solar cells with high total current densities (sum of the top and bottom cell current density) of up to 26.8 mA cm^− 2 were fabricated.     

Indium-doped ZnO thin films deposited by the sol–gel technique

Conducting and transparent indium-doped ZnO thin films were deposited on sodocalcic glass substrates by the sol–gel technique. Zinc acetate and indium chloride were used as precursor materials. The electrical resistivity, structure, morphology and optical transmittance of the films were analyzed as a function of the film thickness and the post-deposition annealing treatments in vacuum, oxygen or argon. The obtained films exhibited a (002) preferential growth in all the cases. Surface morphology studies showed that an increase in the films' thickness causes an increase in the grain size. Films with 0.18 μm thickness, prepared under optimal deposition conditions followed by an annealing treatment in vacuum showed electrical resistivity of 1.3 × 10^− 2 Ωcm and optical transmittance higher than 85%. These results make ZnO:In thin films an attractive material for transparent electrodes in thin film solar cells.     

基于NCPI理念建设新型高校机房

根据NCPI理念,结合新颁布的《电子信息系统机房设计规范》,从降低投资成本、设备节能设计、安全设计三个方面,探讨了在高校机房建设中应该注意的问题。     

Properties of ZnO/Cu/ZnO multilayer films deposited by simultaneous RF and DC magnetron sputtering at different substrate temperatures

ZnO/Cu/ZnO transparent conductive multilayer films are prepared by simultaneous RF sputtering of ZnO and DC sputtering of Cu. The properties of the multilayer films are studied at different substrate temperatures. Sheet resistance of the multilayer film decreased initially with increase of substrate temperature and increased further with increase of substrate temperature beyond 100 °C. However, transmittance of the multilayer film increased with increase of substrate temperature. Good transparent conductive film of sheet resistance 9.3 Ω/sq and transmittance of 85% was found at a substrate temperature of 100 °C. The performance of the multilayer film was evaluated using a figure of merit. The observed property of the multilayer film is suitable for the application of transparent conductive electrodes.     

Influence of dysprosium doping on the electrical and optical properties of CdO thin films

Lightly Dy-doped CdO thin films (molar 0.5%, 1%, 2%, and 2.5%) have been prepared by a vacuum evaporation method on glass and Si wafer substrates. The prepared films were characterised by X-ray fluorescence, X-ray diffraction, UV-vis-NIR absorption spectroscopy, and dc-electrical measurements. Experimental data indicate that Dy³⁺ doping slightly stretchy-stresses the CdO crystalline structure and changes the optical and electrical properties. The bandgap of CdO was suddenly narrowed by about 20% due to a little doping with Dy³⁺ ions. Then, as the Dy doping level was increased, the energygap was also increased. This variation was explained by the effect of Burstein-Moss energy shift (or bandgap widening effect) together with a bandgap shrinkage effect. The electrical behaviour of the samples shows that they are degenerate semiconductors. However, the 2% Dy-doped CdO sample shows an increase in its mobility by about 3.5 times, conductivity by 35 times, and carrier concentration by 10 times relative to undoped CdO film. From transparent conducting oxide point of view, Dy is sufficiently effective for CdO doping.     

Electrical and optical properties of ZnO thin film as a function of deposition parameters

Al-doped zinc oxide (AZO) and undoped zinc oxide (ZO) films have been prepared by rf magnetron sputtering. Films with low resistivities were achieved by using an Al-doped ZnO target and films with higher resistivities can be obtained by introducing oxygen during deposition. An AZO thin film which was fabricated with an rf power of 180 W, a sputtering pressure of 10 mTorr and thickness of 5000 Å showed the lowest resistivity of 1.4×10⁻⁴ Ω cm and transmittance of 95% in the visible range, and ZO film made by reactive sputtering with the above 10% oxygen content had the highest resistivity of 6×10¹⁴ Ω cm.     

Optical properties of silicon-based thin-film solar cells in substrate and superstrate configuration

The optical properties of microcrystalline silicon substrate-type solar cells with a front ZnO thickness of 500–1000 nm as required for monolithic series connection in PV-modules are investigated. The surface texture of the front ZnO was varied to study the possibility to reduce reflection losses and to improve light trapping. Before encapsulation, certain textures of the front ZnO exhibit improved light coupling for substrate solar cells. For substrate solar cells encapsulated with EVA and a glass cover, however, additional texture of the front ZnO has hardly any effect. Encapsulation also removes the antireflection conditions in case that the front ZnO was originally designed as ARC. So far, the quantum efficiency of encapsulated substrate solar cells does not show the high level as observed in superstrate solar cells possibly due to parasitic absorption in the front and back contact and the not optimized texture of the reflector (substrate).     

Ray tracing for the optics at nano‐textured ZnO–air and ZnO–silicon interfaces

We investigate the scattering behavior of nano‐textured ZnO–Air and ZnO–Silicon interfaces for the application in thin film silicon solar cells. Contrary to the common approach, the numerical solution of the Maxwell's equations, we introduce a ray tracing approach based on geometric optics and the measured interface topography. The validity of this model is discussed by means of scanning near‐field optical microscopy (SNOM) measurements and numerical solutions of the Maxwell's equations. We show, that the ray tracing model can qualitatively describe the formation of micro lenses, which are the dominant feature of the local scattering properties of the investigated interfaces. A quantitative analysis for the ZnO–Silicon interface at λ = 488 and 780 nm shows that the ray tracing model corresponds well to the numerical solution of the Maxwell's equations, especially within the first 1.5 µm distance from the interface. Direct correlations between the locally scattered intensity and the interface topographies are found. Copyright © 2011 John Wiley & Sons, Ltd.