Effect of electron beam irradiation on the electrical and optical properties of ITO/Ag/ITO and IZO/Ag/IZO films

We have investigated the effect of electron beam irradiation as well as insertion of a Ag layer on the electrical and optical properties of the ITO or IZO films. The results show that electron beam irradiation as well as inserting a very thin Ag layer can significantly reduce sheet resistance of the ITO/Ag/ITO and IZO/Ag/IZO films. The electron beam irradiation also increases light transmittance and optical band gap of the ITO/Ag/ITO multilayer films; meanwhile, it has not influence on the transmittance of the IZO/Ag/IZO films. These results can be explained by that In and Zn cation in IZO film have strong tendency to preserve their coordination with oxygen.     

Rough ZnO layers by LP-CVD process and their effect in improving performances of amorphous and microcrystalline silicon solar cells

Doped ZnO layers deposited by low-pressure chemical vapour deposition technique have been studied for their use as transparent contact layers for thin-film silicon solar cells.Surface roughness of these ZnO layers is related to their light-scattering capability; this is shown to be of prime importance to enhance the current generation in thin-film silicon solar cells. Surface roughness has been tuned over a large range of values, by varying thickness and/or doping concentration of the ZnO layers.A method is proposed to optimize the light-scattering capacity of ZnO layers, and the incorporation of these layers as front transparent conductive oxides for p–i–n thin-film microcrystalline silicon solar cells is studied.     

Damp heat stability of Al-doped zinc oxide films on smooth and rough substrates

Properly encapsulated chalcopyrite-based solar modules from a number of manufacturers have passed the accelerated ageing tests in damp heat.Non-encapsulated modules after damp heat exposure show an increased series resistance which is contributed significantly from the increase in lateral sheet resistance of the transparent Al-doped zinc oxide (ZAO) front contact. We have shown previously, that a rough substrate morphology (on a μm-scale) is a major influence in the ZAO degradation mechanism, due to local perturbations of the ZAO growth (extended grain boundaries).To further model and examine the extended grain boundaries we present a study of the electrical properties of RF-sputtered ZAO films before and after damp heat, grown on rough quartz glass as well as on polished, texture-etched and patterned silicon. The pattern consisted of equidistant trenches and have a periodical two-dimensional geometry.The strongest decrease of ZAO conductivity occurs on the patterned silicon substrate perpendicular to the trenches. The conductivity parallel to the trenches, however, had the same trend as the conductivity of ZAO on smooth silicon. Measured activation energies of the conductivity of 40 meV or less after damp heat are not sufficient to explain the drastic decrease of conductivity in terms of a grain-boundary-barrier theory (as described, e.g., by Seto). We will summarise our current understanding of the extended grain boundaries and present a refined barrier model to explain our experimental observations.     

投弹式检测技术在转炉炼钢中的应用

阐述了投弹式检测技术(TCO)的装备结构、技术原理及其在炼钢操作过程中的作用.介绍了TCO技术在华西钢铁有限公司40 t 转炉上的应用效果,指出了TCO技术在我国推广应用的前景.     

The effects of glossy screens on the acceptance of flat‐panel displays

Abstract— The TCO requirements provide well‐known and recognized quality labels for displays. For these requirements to remain useful, they must continuously be reviewed and updated when necessary. The study described here was performed in response to the market trend of designing flat‐panel displays and notebooks with glare panels. The purpose of this study was to investigate subjective responses to display screens of different gloss levels for office workers working on different tasks under normal office‐lighting conditions. The study consisted of three parts, one where the users should set an acceptable reflex level, one where the user should rate their disturbance on a category scale, and one where the visual acuity of the users were investigated whether they were affected by glare or not. The results show that increasing gloss and increasing luminance levels had negative effects on the acceptance and the disturbance of reflexes. There were statistically significant differences in the acceptance and the disturbance levels between screens with low gloss and screens with high gloss, which suggests that screens with the highest gloss levels should be avoided. The study did not show an effect on the performance based on acuity testing.     

Production and characterization of ITO-Pt semiconductor powder containing nanoscale noble metal particles catalytically active in dye-sensitized solar cells

Doped indium tin oxide (ITO) samples of a surface area around 60 m²/g have been synthesized. As doping component platinum and gold atoms were utilized, respectively. The powders were produced by pyrolyzing mixed metal oxide precursors in a first zone in a flame consisting of hydrogen and air, metering a noble metal compound and reducing gas into a second zone of the flame and separating off the solid obtained in a third zone. Well-defined solid phases In₂Pt and In₂Au in ITO were obtained, respectively. The production of a mixture with discrete SnO₂ entities could be avoided. The mixed oxide powder doped with platinum can be used as a catalyst. The structure and composition of materials obtained at different levels of platinum dosing into a flame reactor has been determined. The size of the noble metal-containing entities ranged at about 3.5–5.5 nm. The catalytic properties of these oxides containing noble metal have been utilized in the fabrication of dye-sensitized solar cells (DSCs). Long term stability of DSCs containing liquid electrolytes requires a glass sealing of the two electrodes at a temperature of over 600 °C. Such high temperatures are detrimental to the catalytic activity of the conventional platinum layers in the counter electrode. Improved catalytic activity could be achieved by platinum entities bound to indium tin oxide. This catalytic material can effectively be used in the DSCs with glass sealing, the sealing temperature being over 600 °C. Spray pyrolysis in a flame reactor is highly suitable to produce noble metal-containing oxides in one single production step. Platinum-containing ITO particles from flame pyrolysis production exhibit superior catalytic activity in dye-sensitized solar cells compared to material from conventional thermal decomposition.     

ZAO特性及其在CIGS电池中的应用

透明导电氧化物薄膜(Transparent Conductive Oxides,简称TCO)用途广泛,介绍了TCO应用于光伏领域中的铜铟镓硒薄膜(CIGS)太阳电池,是CIGS太阳电池中不可缺少的一部分。简要阐述了其可见光范围内的透明性和导电性及其成因,以及作为CIGS薄膜太阳电池中窗口层的作用。将ITO和ZAO透明导电薄膜在CIGS太阳电池的应用进行相比,以掺铝的氧化锌(ZnO∶Al简称ZAO)透明导电薄膜为例,对其性能、制备方法及过程进行了简要阐述,并概括了大面积ZAO薄膜的性能。     

Improving carriers mobility in copper and iron-codoped CdO

Thin films of Fe and Cu-codoped CdO (CdO:Cu:Fe) with different Fe content and fixed Cu content were deposited in a high vacuum on glass and Si wafer substrates. These films were studied by X-ray fluorescence (XRF), X-ray diffraction (XED), optical spectroscopy, and dc-electrical measurements. The structural results show enhancement of film [1 1 1] orientation with Fe doping especially with 1.3%Fe film. Also, light doping with Fe improves the dc-conduction parameters of the CdO:Cu:Fe films so that the utmost enhancement of mobility (90.5 cm²/Vs) and conductivity (1470.6 S/cm) was found with 1.3 wt% Fe doping level. It was found that the variation in the bandgap is related to the variation in electron concentration that caused by Fe doping. For low Fe ion concentration (<1.3 wt% ), the bandgap varies according to the Moss–Burstein model.     

Development of transparent conducting copper and iron co-doped cadmium oxide films: Effect of annealing in hydrogen atmosphere

Hydrogenated (annealed in hydrogen atmosphere) cadmium oxide (CdO) thin films co-doped with iron (Fe) of different levels and fixed (2.5%) copper (Cu) amount were deposited on glass and silicon wafer substrates by thermal evaporation. The films were characterised with X-ray fluorescence, X-ray diffraction, optical spectroscopy, and dc-electrical measurements. The obtained results show important improvements in the conductivity, mobility, and carrier concentration compared to un-doped and non-hydrogenated CdO. Hydrogenated CdO doped with 2.5% Cu and 1.3% Fe improved the conductivity (2293.6 S/cm) by ~46 times, mobility (78.31 cm²/V s) by ~11 times, and carrier concentration (1.82×10²⁰ cm⁻³) by ~4 times. This suggests the possibility of using CdO:Cu:Fe–H as transparent-conducting-oxide and dilute-magnetic-semiconductor field of applications.     

An iterative mathematical decision model for cloud migration: A cost and security risk approach

This paper presents an iterative mathematical decision model for organizations to evaluate whether to invest in establishing information technology (IT) infrastructure on‐premises or outsourcing IT services on a multicloud environment. This is because a single cloud cannot cover all types of users’ functional/nonfunctional requirements, in addition to several drawbacks such as resource limitation, vendor lock‐in, and prone to failure. On the other hand, multicloud brings several merits such as vendor lock‐in avoidance, system fault tolerance, cost reduction, and better quality of service. The biggest challenge is in selecting an optimal web service composition in the ever increasing multicloud market in which each provider has its own pricing schemes and delivers variation in the service security level. In this regard, we embed a module in the cloud broker to log service downtime and different attacks to measure the security risk. If security tenets, namely, security service level agreement, such as availability, integrity, and confidentiality for mission‐critical applications, are targeted by cybersecurity attacks, it causes disruption in business continuity, leading to financial losses or even business failure. To address this issue, our decision model extends the cost model by using the cost present value concept and the risk model by using the advanced mean failure cost concept, which are derived from the embedded module to quantify cloud competencies. Then, the cloud economic problem is transformed into a bioptimization problem, which minimizes cost and security risks simultaneously. To deal with the combinatorial problem, we extended a genetic algorithm to find a Pareto set of optimal solutions. To reach a concrete result and to illustrate the effectiveness of the decision model, we conducted different scenarios and a small‐to‐medium business IT development for a 5‐year investment as a case study. The result of different implementation shows that multicloud is a promising and reliable solution against IT on‐premises deployment.