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Influence of Electrochemical Deposition Parameters on Morphological Properties of ZnO on Si (100)
摘要： In this study, ZnO layer was deposited on Si (100) by electrochemical deposition (ECD) technique. Mixture of zinc chloride (ZnCl2) and potassium chloride (KCl) at different volume ratio was used as the electrolyte. The current density was fixed at 10 mA/cm2 with deposition time of 50 and 30 minutes. The effect of substrate treatment has also been observed to improve the adhesion of the deposited layer. The morphology of the ZnO layer was analyzed using field emission scanning electron microscopy (FESEM), and variable pressure scanning electron microscopy (VPSEM) equipped with energy dispersive X-ray (EDX) module. Four types of ZnO structure had been obtained; needle, flake, coral and pillar-like structures at different deposition conditions. These structures were obtained by changing several parameters such as substrate doping and chloride medium of electrolyte. It was found that the flake-size become smaller as the amount of Chloride ion (Cl-) in electrolyte increased. In addition, substrate type also found to affect the deposition process. As indicated by the EDX spectra, the ZnO is managed to fully cover the target area of deposition for the n-type Si substrate but a bit poor on p-type Si substrate. The targeted EDX ratio of Zn:O is 1:1, which indicates balance stoichiometry of ZnO. However, the best EDX ratio of Zn:O found in this study was only 1.4:1 which was achieved from deposition on p-type Si substrate with no post-annealing applied. The thickness of deposited ZnO was found to decrease with decreasing deposition time. The average thickness was more than 150 μm for 50 minute deposition while 30 minutes deposition yielded thickness less than 100 μm. It is clearly shown that parameters such as time, electrolyte volume ratio and substrate doping have influence on the morphology and thickness of the deposited ZnO on Si (100) by ECD process.
关键词： morphology,electrochemical deposition,zinc oxide
更新于2025-09-23 15:21:21
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Synthesis of hollow spheres of BiFeO3 from nitrate solutions with tartaric acid: Morphology and magnetic properties
摘要： Single-phase powders of bismuth ferrite have been synthesized for the first time by ultrasonic spray pyrolysis from nitrate solution in the presence of tartaric acid. The produced powders consist of hollow spherical agglomerates with a mean diameter of ~1 μm. The influence of tartaric acid concentration on the synthesis temperature and morphology of hollow spheres was established. The agglomerate shells have open and closed pores. The mean values of the shell thickness and the ratios of closed and open pores were estimated and their dependence on the concentration of tartaric acid was found. It was shown that the magnetic properties are determined not only by the size of nanoparticles composing the agglomerates, but also by the morphology of hollow sphere shells.
关键词： hollow spheres,morphology,magnetic properties,multiferroics,bismuth ferrite
更新于2025-09-23 15:21:21
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Morphology of TiO2 Layers with a Well-Developed Acicular–Fibrous Structure in VT-20 Titanium
摘要： We have studied the effect of size factors of substrates on the formation of TiO2 layers with a well-developed acicular–fibrous structure on VT-20 titanium. The proposed technique allows a TiO2 layer with a large surface area to be produced by etching in a KOH solution (without using hydrothermal synthesis conditions), followed by heat treatment. The layers thus produced consist of fibers 20–100 nm in diameter and up to 1 μ m in length, which are strongly bonded to the substrate surface. Their phase composition is dominated by rutile. The fiber growth process is shown to be influenced by substrate etching and heat treatment conditions, weakly influenced by the curvature of the substrate, and independent of its dimensions.
关键词： large surface area,acicular structure,morphology,titania
更新于2025-09-23 15:21:21
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Tuning the Cross-Linker Crystallinity of a Stretchable Polymer Semiconductor
摘要： The cross-linking of conjugated polymers has been demonstrated to be an effective strategy to improve its elastic properties to give deformable semiconductors for plastic electronics. While there have been extensive studies of the structural requirements of the polymer host for good film ductility, no work to date has focused on the relevance of the structural design or chemistry of these cross-linker additives. In this study, urethane groups and tertiary carbon atoms are inserted into the alkyl backbone of perfluorophenyl azide-based cross-linkers to investigate the importance of cross-linker crystallinity with respect to polymer morphology and hence mechanical and electrical properties. Linear cross-linkers with hydrogen bonding from urethane groups readily phase separate and recrystallize in the polymer network to form cross-linked domains that obstruct the strain distribution of the polymer film. Branch cross-linkers with tertiary carbon on the other hand form an evenly cross-linked network in the polymer blend stemming from excellent miscibility and show a 4-fold increase in fracture strain. Furthermore, a stable hole mobility of 0.2 cm2 V?1 s?1 is achieved up to ε = 100%, and a stable hole mobility of 0.1 cm2 V?1 s?1 after 2000 cycles of ε = 25% on fully stretchable organic field-effect transistors.
关键词： cross-linking,deformable semiconductors,cross-linker crystallinity,electrical properties,polymer morphology,elastic properties,plastic electronics,conjugated polymers,mechanical properties
更新于2025-09-23 15:21:21
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Simple Lithography-Free Single Cell Micropatterning using Laser-Cut Stencils
摘要： Micropatterning techniques have been widely used in cell biology to study effects of controlling cell shape and size on cell fate determination at single cell resolution. Current state-of-the-art single cell micropatterning techniques involve soft lithography and micro-contact printing, which is a powerful technology, but requires trained engineering skills and certain facility support in microfabrication. These limitations require a more accessible technique. Here, we describe a simple alternative lithography-free method: stencil-based single cell patterning. We provide step-by-step procedures including stencil design, polyacrylamide hydrogel fabrication, stencil-based protein incorporation, and cell plating and culture. This simple method can be used to pattern an array of as many as 2,000 cells. We demonstrate the patterning of cardiomyocytes derived from single human induced pluripotent stem cells (hiPSC) with distinct cell shapes, from a 1:1 square to a 7:1 adult cardiomyocyte-like rectangle. This stencil-based single cell patterning is lithography-free, technically robust, convenient, inexpensive, and most importantly accessible to those with a limited bioengineering background.
关键词： iPSC-CM,Developmental Biology,hydrogel,lithography-free,cell morphology,stencil,single cell micropatterning
更新于2025-09-23 15:21:01
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Development of Combinatorial Pulsed Laser Deposition for Expedited Device Optimization in CdTe/CdS Thin-Film Solar Cells
摘要： A combinatorial pulsed laser deposition system was developed by integrating a computer controlled scanning sample stage in order to rapidly screen processing conditions relevant to CdTe/CdS thin-film solar cells. Using this system, the thickness of the CdTe absorber layer is varied across a single sample from 1.5 ??m to 0.75 ??m. The effects of thickness on CdTe grain morphology, crystal orientation, and cell efficiency were investigated with respect to different postprocessing conditions. It is shown that the thinner CdTe layer of 0.75 ??m obtained the best power conversion efficiency up to 5.3%. The results of this work shows the importance that CdTe grain size/morphology relative to CdTe thickness has on device performance and quantitatively exhibits what those values should be to obtain efficient thin-film CdTe/CdS solar cells fabricated with pulsed laser deposition. Further development of this combinatorial approach could enable high-throughput exploration and optimization of CdTe/CdS solar cells.
关键词： combinatorial pulsed laser deposition,power conversion efficiency,grain morphology,CdTe/CdS thin-film solar cells,device optimization,crystal orientation
更新于2025-09-23 15:21:01
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Tunable spectrum resemblance of LED lights for improving the photosynthetic action of Chinese Cabbages
摘要： To increase efficiency, and reduce energy loss and waste, we propose to improve the photosynthetic action spectrum resemblance (SRPAS) of LED light with the absorption spectra of the fresh leaf, for accelerating the growth of Chinese Cabbages. Eight spectral LED lights were adopted to irradiate Chinese Cabbages under 150 μmol·m-2·s-1 for a 16 hd-1 photoperiod. Of these, under the irradiation of blue + broad red + more yellow (BRY2) light with high spectrum resemblance of 75%, the fresh weight and dry weight are 5.1times and 3.0 times, respectively, and the leaf area and leaf number are 1.7 times, as high as under the blue light. The results demonstrate that the optimized LED light can be presumed to have the highest spectrum resemblance (SRPAS) with the absorption spectra of Chinese Cabbages, and the highest energy-conversion efficiency. These conclusions may be of great benefit to further assess and find either an ideal light applied for plant growth or design of better light sources for growing different plants.
关键词： Absorption spectrum,Photosynthetic action spectrum resemblance,LED lighting,Growth and morphology,Chinese Cabbages
更新于2025-09-23 15:21:01
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Microwave-assisted synthesis of ZnO nanostructures for organic solar cell applications
摘要： In this work, a simple and efficient microwave-assisted hydrothermal method was adopted to synthesis zinc oxide nanostructures. Zinc acetate and hexamethylenetetramine were used as precursors. Various parameters involving synthesis conditions were attuned in order to achieve well-defined morphology. XRD peaks indicated the high crystallinity and hexagonal wurtzite structure of the prepared material. Field emission scanning electron microscopy revealed different morphology of the synthesized material. The prepared material can be used in organic solar cells, for effective dissociation of electron-hole pairs and thus enhancing photovoltaic performance.
关键词： Morphology,Organic solar cells,Microwave,Nanostructures,ZnO
更新于2025-09-23 15:21:01
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Organic solar cells probed with advanced neutron scattering techniques
摘要： Neutron scattering techniques provide unique insights into the active layer morphology of organic solar cells. The nanoscale morphology, the thin film vertical composition, and the intermixing on a molecular level, which all strongly have an impact on the performance of organic solar cells, can be probed with neutrons. In addition to the static structure, also fast dynamics occurring in the active material is accessible with neutrons. This perspective letter highlights the power of grazing incidence small angle neutron scattering and quasi-elastic neutron scattering experiments after shortly introducing into the working principle of organic solar cells.
关键词： neutron scattering,grazing incidence small angle neutron scattering,morphology,quasi-elastic neutron scattering,organic solar cells
更新于2025-09-23 15:21:01
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Over 15.7% Efficiency of Ternary Organic Solar Cells by Employing Two Compatible Acceptors with Similar LUMO Levels
摘要： Efficient organic solar cells (OSCs) are fabricated using polymer PM6 as donor, and IPTBO-4Cl and MF1 as acceptors. The power conversion efficiency (PCE) of IPTBO-4Cl based and MF1 based binary OSCs individually arrive to 14.94% and 12.07%, exhibiting markedly different short circuit current density (JSC) of 23.18 mA cm?2 versus 17.01 mA cm?2, fill factor (FF) of 72.17% versus 78.18% and similar open circuit voltage (VOC) of 0.893 V versus 0.908 V. The two acceptors, IPTBO-4Cl and MF1, have similar lowest unoccupied molecular orbital levels, which is beneficial for efficient electron transport in the ternary active layer. The PCE of optimized ternary OSCs arrives to 15.74% by incorporating 30 wt% MF1 in acceptors, resulting from the simultaneously increased JSC of 23.20 mA cm?2, VOC of 0.897 V, and FF of 75.64% in comparison with IPTBO-4Cl based binary OSCs. The gradually increased FFs of ternary OSCs indicate the well-optimized phase separation and molecular arrangement with MF1 as morphology regulator. This work may provide a new viewpoint for selecting an appropriate third component to achieve efficient ternary OSCs from materials and photovoltaic parameters of two binary OSCs.
关键词： organic solar cells,morphology regulators,compatible acceptors,ternary strategy
更新于2025-09-23 15:21:01