bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Samarium on Hydrogen Absorption during the Nickel Electrodeposition on Palladium
Authors: Flores Luis , Lopez Juan Ramon , Trejo Gabriel , Perez Jose de Jesus , Antaño López Rene , Mojica José , Meas Yunny 
Published: February 2020

During the nickel electrodeposition process, secondary reactions corresponding to the reduction of a proton to Hads and the evolution of molecular hydrogen occur. The Hads could be absorbed and diffused in the substrate. In this work, we studied the effect of samarium on the process of hydrogen permeation that carries out during the electrodeposition of nickel from a nickel sulfamate bath which also contains the tensioactive SDS (sodium dodecyl sulfate). The experiments were carried out at pH 3 and T=25 ° C, with a Devanathan Starchuski cell and with different concentrations of SDS and Sm.
According to the results obtained from the permeation current and the hydrogen diffusion in the metal, we observe that additions of SDS and Sm at concentrations of 0.1g/l and 2g/l respectively will decrease the hydrogen absorption in the substrate. The influence of these additives on the mechanism of hydrogen absorption will be discussed.
Membrane Technologies for Renewable Energy Conversion and Storage
Authors: Xu Hui 
Published: February 2020

The utilization of renewable energy has substantially driven more investments into electrolysis technologies. As renewable energy emerges and penetrates further into the energy market, the storage of surplus “off peak” electricity has received widespread attention. An electrolyzer can utilize “off peak” electricity from solar or wind farms to produce hydrogen or other fuels. These chemicals can then be operated in a fuel cell mode to generate electricity when needed or used for other industrial applications. It is estimated that the water electrolyzer market can increase up to 300 GW over the next two decades. The power to gas market alone is poised to become a multi-billion-dollar market for on-site water electrolysis systems over the next decade.
However, current hydrogen production from electrolysis comprises only a small fraction of the global hydrogen market due to the high costs that results from expensive materials even if “free” electricity from renewable energy can be acquired. Giner has been a world leader in researching, developing and manufacturing water electrolyzers and reversible fuel cells. We have been striving to develop the membrane technology to improve electrolyzers’ performance, extend their lifetimes, and lower their capital costs. These efforts include: 1) increasing membrane conductivity; 2) tailoring membrane gas and water permeability; 3) enhancing membrane mechanical strength; 4) prolonging membrane durability; 4) lowering its cost.
In addition to water electrolysis for hydrogen production, electrochemical synthesis of ammonia and CO2 conversion to hydrocarbon fuels have also been extensively investigated at Giner. Advanced membranes have been developed to enhance the conversion rate and boost the process efficiency. For example, the electrochemical production of ammonia from nitrogen and water has thus led to tremendous energy savings compared to the conventional Haber-Bosch process. The produced ammonia can be used as low-cost energy carrier for fuel cell vehicles.
Evaluating Microstructure and Transport within Flow Electrodes for Capacitive Deionization
Authors: Dixit Marm , Moreno Daniel , Hatzell Kelsey B , Hatzell Marta C. 
Published: February 2020

Flow electrode capacitive deionization is a emerging approach for electrochemical desalination. It mitigates several challenges associated with film or membrane capacitive deionization through transforming the electrodes from a static electrode into a suspension electrode. This enables greater surface area, and by consequence higher saline water treatment. The major disadvantage associated with flow electrode capacitive deionization is the high cell resistance and pumping energy. Electrodes with high weight percent minimize resistance but maximize pumping energy, and conversely low weight percent electrodes have reduced pumping energy but increased whole cell resistance. Here, we will present structure-property relationships relevant for static and flowing flow electrodes. The structure-property relationships are obtained through reconstructing the 3-D structure using x-ray tomography[1]. these relationships are then used to predict desalination performance in a bench scale desalination cell.
[1]Hatzell, K. B., Eller, J., Morelly, S. L., Tang, M. H., Alvarez, N. J., & Gogotsi, Y. (2017). Direct observation of active material interactions in flowable electrodes using X-ray tomography. Faraday discussions, 199, 511-524.
Self-Regenerating Oil Absorbent Via Wettability Switch Using Electrochemical Redox of Conjugated Polymer Surfaces
Authors: Xu Jian , Fu Shichen , Xu Wei , Yang Eui-Hyeok 
Published: February 2020

There exists a huge demand for efficient, reliable and safe technologies for oily water treatment and/or oil recovery. Among many techniques, absorbent-based technology shows the possibility of full removal and reclaim of oils from water, while bringing little adverse effects to the environment [1]. In spite of their promises, the issues pertaining to the recycling and regenerating of saturated absorbents have been less-explored [1, 2].
In this work, we demonstrate a conjugated polymer mesh as oil absorbent capable of in situ self-regeneration via wettability switch during electrochemical oxidation and reduction. We fabricate the absorbent through electropolymerization of polypyrrole-dodecylbenzenesulfonate (PPy(DBS)) on the surfaces of carbon nanotubes (CNTs) grown out of the surface of a stainless steel (SS) mesh. The PPy(DBS)-coated mesh shows oleophilic property when electrochemically oxidized, allowing the mesh to absorb oils (i.e., oils stick to the polymer surface; oils are trapped within the micro-pores of mesh). Under reduction, the surface switches to oleophobic (i.e., oils do not stick to the polymer surface), which allows trapped-oils by the mesh to be released, while in situ self-regenerating the polymer surface. We also observe that this switchable adhesion property is further enhanced incorporating CNTs into the structure. Using this approach, in situ absorbing and releasing of dichloromethane (DCM) in aqueous solution is demonstrated using a rolled-up absorbent mesh. We further demonstrate the wettability switch performance (characterizing the retention force when oxidized and switch time when reduced) of the absorbent during 250 redox cycles. In addition, the potential usage of this oil absorbent for oil/water separation is demonstrated by transporting DCM from one vial to another. Together, this novel adsorbent shows great promise towards high-efficient continuous oil/water separation applications.
[1] J. Ge, H. Zhao, H. Zhu, J. Huang, L. Shi, and S. Yu, “Advanced sorbents for oil-spill cleanup: recent advances and future perspectives,” Advanced Materials, 28 (47), 10459–10490, (2016).
[2] Z. Chu, Y. Feng, and S. Seeger, “Oil/water separation with selective superantiwetting/superwetting surface materials,” Angewandte Chemie - International Edition, 54 (8), 2328–2338, (2015).
CFD Modelling of an Electrodialysis Cell
Authors: Quiñones Félix Tonatiuh , Camacho Mara Patricia , Rodríguez Francisca Alicia , Ortega Arturo , Cruz-Díaz Martin Rogelio , Rivero Eligio Pastor 
Published: February 2020

Electrodialysis (ED) cells are based on the selective transport of ions through membranes which ideally exclude the co-ions, so that when a potential difference is applied to the cell all ions are transported in solution but only the counter ions can cross the membrane. Thus, concentration polarization occurs in solutions adjacent to membrane surfaces due to the different transport number between the membrane and the solution. The concentration profiles formed in the solution near the membrane depends on the mass transport fluxes and hydrodynamic pattern in the channel; operating conditions and geometrical configuration of the cell affect greatly the concentration polarization [1]. Therefore, the performance of ED cells depends not only on the membrane properties but also on the electrolyte hydrodynamics being important to provide an adequate flow patter avoiding channeling, stagnant zones, jet formation, among others flow deviations. Keeping a homogeneous flow patter minimizes variations of mass transfer fluxes and current density over the membrane surface preventing high polarization zones that could give rise to water dissociation, low efficiency and premature membrane failure. The examination of relevant mass transport mechanisms by modelling can help to evaluate the effect of design characteristics and operating conditions on the performance of an electrodialysis cell through the analysis of concentration, potential and current density distributions. In this task, CFD has proven to be a valuable tool for the analysis of flow and mass transfer in membrane separation systems [2]. Therefore, this work presents the modelling of a laboratory ED cell coupling hydrodynamics and mass transport, taking into consideration changes of Donnan potential. The flow pattern inside channels of ED cell were obtained by 3D CFD modeling and the results were used to calculate the residence time distribution (RTD) to compare with experimental RTD. The hydrodynamic behavior was used then to solve the mass transport model to obtain a description of the concentration distribution of each of the ionic species in the cell, as well as of the amounts derived as fluxes of each of the components, current density and Donnan potentials at every point of the membrane.
[1] Gurreri L., Tamburini A., Cipollina A., Micale G., Ciofalo M., CFD prediction of concentration polarization phenomena in spacer-filled channels for reverse electrodialysis J. Membr. Sci. 468, 133–148 (2014).
[2] Fimbres-Weihs G.A., Wiley D.E., Review of 3D CFD modeling of flow and mass transfer in narrow spacer-filled channels in membrane modules, Chem. Eng. Process. 49 759–781 (2010).
Impact of Multiple Debonding on Adhesion Energy
Authors: Fournel Frank , Larrey Vincent , Rieutord François , Morales Christophe , Bridoux Claudine , Mauguen Gaelle , Lobo Sofia 
Published: February 2020

Direct bonding energy relates to the well-known “strength” or “toughness” of direct bonding interface. It is the energy needed to separate two bonded surfaces. In contrast, adhesion energy is the energy available to bring the two surfaces together. Due to hysteretic effects, the two energies may be different and, while the first energy has been largely measured, the second one is the subject of very few papers only [1, 2, 3].
In this study, a new phenomenon will be shown in the adhesion energy behaviour using two silicon wafers. As shown in figure 1b, several partial debondings and rebondings of the same silicon direct bonding structure result in an increase of the bonding wave speed. After reaching a maximum bonding wave speed, a full debonding brings the speed back to its initial value. As it has already been shown theoretically by Rieutord et al. [4] and verified experimentally by Larrey et al. [3], the bonding wave speed is linked to the adhesion energy of the system. Therefore, an increase of the bonding wave speed consequently indicates an increase of the adhesion energy. As shown in figure 1b, multiple partial debondings increase the bonding wave speed by more than 50%, which increases the adhesion energy by more than 40%. The relationship between adhesion energy and bonding wave speed is not linearly dependent, as defined in the equation of figure1a [4] and shown in figure1c.
Different experiments have been done to find the cause of this peculiar behavior. A model will be proposed and discussed.

REFERENCES

[1] D. Grierson and K.T. Turner, ECS Trans. 33, 573 (2010).
[2] D. Radisson, Direct Bonding of Patterned Surfaces, phdthesis, Université Grenoble Alpes, 2014.
[3] V. Larrey, G. Mauguen, F. Fournel, D. Radisson, F. Rieutord, C. Morales, C. Bridoux, and H. Moriceau, ECS Trans. 75, 145 (2016).
[4] F. Rieutord, B. Bataillou, and H. Moriceau, Physical Review Letters 94, (2005).

Figure 1
Collective Die Direct Bonding for Photonic on Silicon
Authors: Sanchez Loic , Fournel Frank , Montmayeul Brigitte , Bally Laurent , Szelag Bertrand , Adelmini Laetitia 
Published: February 2020

Integrated transmitters incorporating lasers and modulators on silicon are of primary importance for all communication applications, and at the same time are the most challenging to manufacture due to the need of hybrid III-V integration. In order to introduce III-V materials in low cost silicon platform manufacturing, direct bonding approach could present a great interest due to the growth limitation of III-V hetero-epitaxial layers directly onto silicon. Furthermore, by using a 100 nm silicon dioxide layer between the silicon wave guide and the III-V active stack, direct bonding allows the optical coupling necessary to build active optical device.
Nevertheless, the potential low cost model of silicon photonic is based only on the hypothesis that we are able to work on the full surface of the 200/300 mm SOI photonic wafer. III-V wafer direct bonding is not suitable to fulfill this requirement for two main reasons. First, the maximum diameter available for III-V wafers is limited to 150 mm up to now. Secondly, the III-V material is necessary only on the emitter and receiver areas which represent only a very little part of the device area. Therefore, the most part of the reported full III-V wafer is lost by the layer patterning on required areas.
To overcome this limitation in term of wafer diameter and to limit the loss of a very expensive starting material we have developed at LETI a collective die direct bonding process. The idea is to bond collectively III-V chips only where there are necessary and on the full photonic SOI surface. The die size is selected to be slightly higher than the targeted area in order to be compatible with a wafer notch alignment and avoid any accurate alignment with alignment marks. The requirements for direct bonding are exactly the same than for wafer bonding, but die direct bonding is obviously more difficult due to the dicing step which generates a high level particle contamination. All the process steps have to be adapted to be compatible with die handling and the die cleaning before bonding have to be strongly optimized to remove this high particle contamination. We have then developed specific silicon die holder in order to clean the die surfaces collectively in classical microelectronics high performance cleaning tools. A test vehicle containing few hundred 3*3 mm² dice will be used to evaluate the collective die direct bonding process. Because III-V materials are not as mature as silicon, the bonding process will be firstly evaluated with silicon dies. After optimization, Indium phosphide dice will be used to validate the global process. Bonding interfaces of dice are finely characterized by Scanning Acoustic Microscopy and SAM images will be processed in order to quantify the bonding yield and the die positioning accuracy.

Figure 1
Temperature Effects on the Performance of Activated Carbon Electrochemical Cell in Aqueous and Non-Aqueous Electrolytes
Authors: Forghani Marveh , Donne Scott W 
Published: February 2020

The aim of this study is to observe the effects of temperature changes on the cycability and the electrochemical performance of activated carbon (AC) electrochemical cell in aqueous (K2SO4) and organic (TEABF4 in acetonitrile) electrolytes.
A series of experiments have been carried out inside of the environmental chamber with temperature ranging from 273 to 313 K for aqueous electrolyte and 263 to 333 K for organic electrolyte. The AC electrochemical cells have been tested using cycling voltammetry (CV) at 25 mV/s sweep rate. This was followed by the step potential electrochemical spectroscopy (SPECS) experiment with a 25 mV potential step and 300 s equilibration time.
SPECS method is based on applying a series of equal magnitude potential steps on a working electrode, with sufficient rest time to allow for equilibrium to be established for each step throughout an applied potential window. This method has been used to effectively differentiate the charge storage contributions from electrical double layer capacitance at the geometric and porous surface areas and diffusion-limited capacitance as a function of scan rate [1].
The outcome of this work indicates the systematic effects of changes in temperature on different charge storage mechanisms. It was expected that the overall electrochemical performance of AC electrochemical cell increases by increasing the temperature in both aqueous and non-aqueous electrolytes, due to increase of kinetic energy of ions in solvent. However, different charge storage mechanism behaved differently in the aqueous and non-aqueous electrolytes. Figure 1. shows the comparison for CV tests (a) in aqueous and (b) in organic electrolytes at different temperatures.
It was found that, the total specific capacitance of AC electrochemical cell is increased by increasing the temperature in aqueous electrolyte. While, in non-aqueous electrolyte, the total specific capacitance decreases by increasing the temperature.
Additionally, SPECS method was used to obtain the contribution of different charge storage mechanisms at different temperatures. The result indicates that the electrical double layer and diffusion limited processes behaved differently in each electrolyte. For instance the capacitance contribution from diffusion-limited processes decreases by increasing the temperature while, the electrical double layer capacitance at the geometric and porous surface areas increases by increasing the temperature in aqueous electrolyte.
Finally, the specific capacitance obtained by the SPECS method was used to obtain the performance of the AC electrochemical cell in the aqueous and non-aqueous electrolytes in the form of a Ragone diagram.
[1]. Marveh Forghani and Scott W. Donne, Journal of the Electrochemical Society 2018 165: A664-A673.

Figure 1
Inherent Area-Selective Growth and Nucleation Enhancement during Ru ALD Using the RuO4-Precursor and H2-Gas
Authors: Minjauw Matthias M. , Rijckaert Hannes , Van Driessche Isabel , Detavernier Christophe , Dendooven Jolien 
Published: February 2020

Ruthenium is a candidate to replace copper in future sub-10 nm interconnects. At these dimensions the resistivity of Ru lines is expected to be lower compared to Cu due to the lower sensitivity to size effects.1 In addition, it is likely that Ru interconnects won’t require a diffusion barrier, and will show a better electromigration performance.2 At feature sizes below 10 nm it will be difficult to align subsequent lithography steps, and the conformality of the deposition method is increasingly important, such that area selective atomic layer deposition (ALD) of ruthenium is of high interest.3

We first report inherent area selective ALD of Ru on H-terminated Si (Si-H) versus SiO2, using the thermal RuO4 (ToRuSTM)/ H2-gas ALD process.4 In situ spectroscopic ellipsometry (SE) on blanket substrates shows that Ru growth initiation occurs from the first cycle on Si-H, while on SiO2 the growth is delayed, resulting in a substrate selectivity window of ~ 70 cycles. Area selective Ru ALD was evaluated using a patterned substrate of 1-10 µm wide Si-H lines separated by 10 µm wide SiO2 regions, and exposing it to 20 cycles of the RuO4 / H2-gas ALD process. Ex situ scanning electron microscopy (SEM) and cross section high resolution transmission electron microscopy (HRTEM) measurements show that a 4.5 nm Ru film could be deposited on the Si-H, with no Ru detected on the SiO2. In vacuo X-ray photoelectron spectroscopy (XPS) experiments showed that exposure of Si-H to a single RuO4 pulse leads to the oxidation of the Si surface, together with the deposition of RuO2. On SiO2 however, the surface is already oxidized, and in vacuo XPS shows that for the same exposure to RuO4 no Ru is deposited on the surface. Therefore, we propose that the mechanism behind the inherent substrate selectivity is the oxidation of the Si-H surface by RuO4. Secondly, we report for a methodology to enhance the nucleation of the RuO4 / H2-gas process on oxide substrates. In vacuo XPS and in situ SE experiments show that a single exposure of SiO2 to trimethylaluminum (TMA) makes the surface reactive towards RuO4, which allows for Ru growth initiation from the first cycle. We propose that this is due to the combustion of surface CH3-groups by RuO4. As TMA is known to be reactive towards many oxide substrates, this methodology presents a way to achieve Ru metallization of virtually any surface.
[1] S. Dutta et al. IEEE Elec. Dev. Lett.
2017, 38, 949.
[2] O. V. Pedreira et al
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2017 IEEE IRPS
, Monterey, CA, 6B-2.1.
[3] P. C. Lemaire et al. J. Chem. Phys.
2017, 146, 052811.
[4] M. M. Minjauw et al. J. Mater. Chem. C. 2015, 3, 132.
(Invited) Epitaxial Germanium and Germanium Tin Alloys By Thermal Chemical Vapor Deposition
Authors: Huang Yi-Chiau 
Published: February 2020

In this work we will discuss the epitaxial growth of both germanium (Ge) and germanium tin (Ge1-xSnx) by thermal chemical vapor deposition. The focus of the discussion is on the challenges we encountered in the development of a low-temperature process to form a Ge layer with a smooth surface and a reasonably low defect level, a Ge1-xSnx layer in a metastable state, or a Ge/Ge1-xSnx stack structure. Examples of surface roughening, relaxation, intermixing, and segregation are given. Device fabrication from individual Ge/Ge1-xSnx layers and stacks will be mentioned.
For Ge growth on Si, we further discuss the importance of process conditions both to minimize the in-film defectivity and to enhance the surface smoothness. The growth selectivity to various dielectric materials shows some interesting dependence on in situ doping and other growth parameters. The dependence of film properties, such as crystallinity and resistivity, on substrate type, such as silicon, silicon germanium, and germanium, is studied. Growth on patterned Si substrates will also be discussed.
With an optimized low-temperature growth process, Sn can be uniformly distributed in Ge to form a homogeneous phase of Ge1-xSnx. The dependence of growth rate and Sn concentration on the Ge and Sn sources is discussed. Sn concentration up 16% can be achieved with decent film quality on a relaxed Ge layer. Fully strained Ge1-xSnx alloys and Ge/Ge1-xSnx stacks have both been used in the fabrication of electronic and photonic devices. The techniques used in stack formation are discussed together with in situ boron and phosphorus doping of Ge/Ge1-xSnx.