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31.
Erkan Aydin Michele De Bastiani Xinbo Yang Muhammad Sajjad Faisal Aljamaan Yury Smirnov Mohamed Nejib Hedhili Wenzhu Liu Thomas G. Allen Lujia Xu Emmanuel Van Kerschaver Monica Morales‐Masis Udo Schwingenschlgl Stefaan De Wolf 《Advanced functional materials》2019,29(25)
Parasitic absorption in transparent electrodes is one of the main roadblocks to enabling power conversion efficiencies (PCEs) for perovskite‐based tandem solar cells beyond 30%. To reduce such losses and maximize light coupling, the broadband transparency of such electrodes should be improved, especially at the front of the device. Here, the excellent properties of Zr‐doped indium oxide (IZRO) transparent electrodes for such applications, with improved near‐infrared (NIR) response, compared to conventional tin‐doped indium oxide (ITO) electrodes, are shown. Optimized IZRO films feature a very high electron mobility (up to ≈77 cm2 V?1 s?1), enabling highly infrared transparent films with a very low sheet resistance (≈18 Ω □?1 for annealed 100 nm films). For devices, this translates in a parasitic absorption of only ≈5% for IZRO within the solar spectrum (250–2500 nm range), to be compared with ≈10% for commercial ITO. Fundamentally, it is found that the high conductivity of annealed IZRO films is directly linked to promoted crystallinity of the indium oxide (In2O3) films due to Zr‐doping. Overall, on a four‐terminal perovskite/silicon tandem device level, an absolute 3.5 mA cm?2 short‐circuit current improvement in silicon bottom cells is obtained by replacing commercial ITO electrodes with IZRO, resulting in improving the PCE from 23.3% to 26.2%. 相似文献
32.
M. Morales M.E. Navarro X.G. Capdevila J.J. Roa M. Segarra 《Ceramics International》2012,38(5):3713-3722
A simple gel-casting method was successfully combined with the spray-coating technique to manufacture graded anode-supported micro-tubular solid oxide fuel cells (MT-SOFCs) based on samaria-doped ceria (SDC) as an electrolyte. Micro-tubular anodes were shaped by a gel-casting method based on a new and simple forming technique that operates as a syringe. The aqueous slurry formulation of the NiO–SDC substrate using agarose as a gelling agent, and the effect of spray-coating parameters used to deposit the anode functional layers (AFLs) and electrolyte were investigated. Furthermore, pre-sintering temperature of anode substrates was systematically studied to avoid the anode–electrolyte delamination and obtain a dense electrolyte without cracks, after co-sintering process at 1450 °C. Despite the high shrinkage of substrate (~70%), an anode porosity of ~37% was achieved. MT-SOFCs with ~2.5 mm of outer diameter, 370 μm thick substrate, 20 μm thick AFLs and 15 μm thick electrolyte were successfully obtained. The use of AFLs with 30:70 and 50:50 wt% NiO–SDC allowed to obtain a continuous gradation of composition and porosity in the anode–electrolyte interface. 相似文献
33.
E.A. Ochoa R. Droppa R.L.O. Basso M. Morales S. Cucatti L.F. Zagonel T. Czerwiec M.C. dos Santos C.A. Figueroa F. Alvarez 《Materials Chemistry and Physics》2013
The low energy (∼50–350 eV) noble gases ion bombardment of the steel surface shows that the pre-treatments increase nitrogen diffusion by modifying the outermost structure of the material. The surface microstructure and morphology of the studied samples were characterized by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The crystalline and chemical structures in the outermost layers of the surface were analyzed by grazing angle X-ray diffraction (GAXRD) and photoemission electron spectroscopy (XPS). Temperature effusion studies of the implanted ions are used to elucidate the noble gases site localization in the network. The local compressive stress induced by the nearby iron atoms on the core level electron wave functions of the trapped noble gases are studied by photoemission electron spectroscopy (XPS) and interpreted considering a simple mechanical model. Nano-hardness measurements show the dependence of the material elastic constant on the energy of the implanted noble gases. Although the ion implantation range is about few nanometers, the atomic attrition effect is larger enough to modify the material structure in the range of micrometers. Two material stress zones were detected where the outermost layers shows compressive stress and the underneath layers shows tensile stress. The implanted noble gases can be easily removed by heating. A diffusion model for polycrystalline-phase systems is used in order to discuss the influence of the atomic attrition on the N diffusion coefficient. The concomitant effect of grain refining, stress, and surface texture on the enhancing nitrogen diffusion effect is discussed. 相似文献
34.
Vinícius D. Silva Rafael A. Raimundo Thiago A. Simões Francisco J.A. Loureiro Duncan P. Fagg Marco A. Morales Daniel A. Macedo Eliton S. Medeiros 《International Journal of Hydrogen Energy》2021,46(5):3798-3810
The development of technologically efficient anodes for water oxidation is crucial to improve hydrogen production via water splitting. Electrodes based on metallic active sites dispersed in carbon matrices have been shown to be an attractive way to attain this goal. However, challenges remain to prevent catalyst agglomeration that otherwise can result in a decrease of performance over time.In this work, we report an alternative and efficient method to produce nickel-nickel oxide nanoparticles-embedded in carbon nanofibers (Ni–NiO/C), by the solution blow spinning (SBS) process. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses show the carbon nanofibrillar matrix as a robust support, with well-dispersed nickel nanoparticles on the surface. The responses of the linear scanning voltammetry, cyclic voltammetry and electrochemical impedance spectroscopy demonstrate how a small fraction of nickel on the fiber surface (≈1.2–5.3%) is enough to promote substantial improvement in performance (η = 278 and 309 mV vs RHE for 10 mA cm?2) and a significant turnover frequency (TOF) values of 1.38 (η = 278) and 1.30 s?1 (η = 309). These promising results are correlated with a large amount of Ni3+ present on the fiber surfaces, as identified by X-ray Photoelectron Spectroscopy (XPS). This work provides a low-cost and rapid preparation technique that can be extended for the manufacture of a wide variety of electrodes based on metals supported on carbon nanofibers. 相似文献
35.
Utilization of proteins from AluProt‐CGNA (a novel protein‐rich lupin variety) in the development of oil‐in‐water multilayer emulsion systems
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36.
The influence of oxidized multi‐walled carbon nanotubes (o‐MWCNTs) on the curing kinetics of a novolac resin was studied by means of non‐isothermal differential scanning calorimetry. Regarding the kinetics issues, the high concentration of hydroxyl groups on the o‐MWCNTs slightly modified the curing reaction of the novolac resin, shifting the differential scanning calorimetry exothermic peak to higher temperatures. The effective activation energy of the curing reaction was calculated by the isoconversional Kissinger‐Akahira‐Sunose method and increased by the presence of o‐MWCNTs with respect to neat novolac. This change was attributed to the increase of the material viscosity. In addition, thermogravimetric analysis revealed that nanocomposites samples containing 0.4 and 1.0 wt% o‐MWCNTs presented increased char yield values, indicating an improvement of flame retardancy. 相似文献
37.
38.
The aim of this work was to investigate the performance and stability of the perovskite La0.5Sr0.5CoO3−δ, as a potential catalyst precursor, for the synthesis gas production by partial oxidation of methane. For this purpose, the catalytic activity of La0.5Sr0.5CoO3−δ was studied as a function of the temperature, flow rate and feed composition. In addition, its stability with the time-on-stream and redox cycles was also explored. Before and after testing, the catalyst precursor was characterized by X-ray diffraction, SEM-EDX and specific surface area (BET). The results evidenced a remarkable catalytic activity due to the stability of the cobalt, which is in a highly disperse state, in its reduced state. The CH4 conversion and the CO and H2 selectivities were enhanced with the increase of redox cycles. Finally, the precursor was totally regenerated to the initial perovskite structure under a specific thermal treatment. 相似文献
39.
40.
Daniel Ortiz Morales Simon Westerberg Pedro X. La Hera Uwe Mettin Leonid Freidovich Anton S. Shiriaev 《野外机器人技术杂志》2014,31(3):343-363
Working with forestry machines requires a great deal of training to be sufficiently skilled to operate forestry cranes. In view of this, it would be desirable within the forestry industry to introduce automated motions, such as those seen in robotic arms, to shorten the training time and make the work of the operator easier. Motivated by this fact, we have developed two experimental platforms for testing control systems and motion‐planning algorithms in real time. They correspond to a laboratory setup and a commercial version of a hydraulic manipulator used in forwarder machines. The aim of this article is to present the results of this development by providing an overview of our trajectory‐planning algorithm and motion‐control method, with a subsequent view of the experimental results. For motion control, we design feedback controllers that are able to track reference trajectories based on sensor measurements. Likewise, we provide arguments to design controllers in an open‐loop for machines that lack sensing devices. Relying on the tracking efficiency of these controllers, we design time‐efficient reference trajectories of motions that correspond to logging tasks. To demonstrate performance, we provide an overview of extensive testing done on these machines. 相似文献