bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Membranes of Mixed Ionic and Electronic Conductors for Gas Separation: Effect of Surface and Interfaces
Authors: Liu Meilin , Liu Mingfei 
Published: February 2020

Dense membranes of mixed ionic-electronic conductors represent a highly efficient and economically viable approach to hydrogen and oxygen separation. For example, a “cermet” membrane consisting of a ceramic proton conductor and a metal (e.g., nickel) could be a promising technical solution for recovery of high-purity hydrogen from synthetic gas mixtures during various industrial processes such as coal gasification and water gas-shift reaction. In particular, yttrium/ytterbium doped barium zirconate-cerate (BZCYYb) exhibits the highest proton conductivity in the temperature range suitable for hydrogen separation. Further, Ni-BZCYYb cermets have high tolerance to sulfur poisoning and coking under typical conditions for hydrocarbon reformation. To date, however, there is little fundamental understanding of the surface processes relevant to hydrogen separation. A fundamental understanding of the charge and mass transport processes associated with H2 dissociation and proton incorporation (or H2 evolution) on the surfaces of a cermet hydrogen permeable membrane is vital to achieving rational design of a new generation of hydrogen permeable membranes. In this presentation, we will highlight our recent progress in understanding the effects of surface and interfaces on gas separation processes, aiming at elucidating the mechanisms that control proton incorporation or H2 dissociation at the surfaces of the membranes, the nature of the proton solubility sites, and the diffusion process through the membrane.
Recovery Cyanide from Cyanide-Containing Wastewater By Selective Electroconcentration
Authors: Yang Yang , Tian Yun , Fan Zheng , Wu Xingxing , Wu Zucheng 
Published: February 2020

A large amount of hydrogen cyanide poisonous gases released from Polyacrylonitrile（PAN）-basis carbon fiber manufacturing process. Stimulated by its value and harmfulness to human and environment, electrochemical methods have proposed to deal with the double-edged materials. A novel electrodeionization technology, named as selective electroconcentration (SEC), was used to segregate targeted ions from mixed aqueous solution. SEC is an approach not only removes needless ions，but also obtains concentrated ions in brine water. In this paper, synthetic water contained cyanide and carbonate was investigated to examine the separation and enrichment effects of SEC. It was found that the pH raise in divalent ions concentrated chamber prevented carbonate conversion, which avoided bicarbonate competing with cyanide. Thus monovalent ions were able to migrate to next concentrated chamber. To acquire details about how to optimize the SEC apparatus, operation parameters like current, pH change, and proportion were discussed here.
Practical results show that cyanide purity can reach 90%, with a high cyanide concentration (250mmol/L). The cyanide product can be used as plating solution. Beyond that, the concentration of treated cyanide wastewater conformed sewage discharge standard. It is proved that SEC is feasible to concentrate cyanide and the separation efficiency is satisfactory.
(Invited) An Industry Perspective on Atomic Layer Etching
Authors: Suri Satyarth , Carver Colin T. , Turkot Robert , Romero Patricio E , Tronic Tristan A , Plombon John 
Published: February 2020

As we celebrate the 50th anniversary of Moore’s Law, the scaling of transistors on a microprocessor at a two year cadence continues. While scaling of critical dimensions (CD) and pitch is widely recognized, the thickness of films that need to be patterned has also scaled down. Additionally, the etch stop films have also become thinner. With pitch scaling, the role of sidewall damage during plasma etch process has become more significant. As the films become thinner and damage free process become more relevant, atomic layer etch as a manufacturing option has become more attractive. This talk will evaluate different atomic layer etch options, discuss the respective pros and cons. Potential enabling examples of atomic layer etch will be presented focusing primarily on atomic layer control, damage reduction and extreme selecitivities.
Understanding Photovoltage in Insulator-Protected Water-Splitting Half-Cells
Authors: Scheuermann Andrew G. , Chidsey Christopher E.D. , McIntyre Paul C. 
Published: February 2020

Metal oxide protection layers for photoanodes may enable the development of large-scale solar fuel and solar chemical synthesis. ALD-TiO2 remains the most widely used material because of its excellent stability under water oxidation conditions and potential for high electrical conductivity both as an ultrathin film and with thicknesses exceeding 100 nm [1-3]. However, the most conductive ALD-TiO2films exhibit poor photovoltages of ~ 400 mV and less [3]. Even assuming near-ideal fill factors, these voltages fall far short of the values needed for viable water splitting devices. Photovoltage optimization is especially difficult in MOS photoanodes due to the range of factors which influence the conductivity and stability of the protection layer as well as the presence of electrically active defect states at the semiconductor/oxide interface. Therefore, understanding how to optimize photovoltage and stability is of utmost concern for the advancement of the field.
Here we report a novel observation of photovoltage loss associated with charge transfer in these metal-oxide protected devices, and by eliminating it, achieve photovoltages as high as 630 mV, the maximum reported to date for single-junction water-splitting silicon cells. The loss mechanism is systematically probed in MOS Schottky junction cells compared to buried junction p+n cells, revealing the need to maintain a characteristic hole density at the semiconductor/insulator interface. A capacitor model that predicts this loss is developed, and is related to the dielectric properties of the protective oxide, achieving excellent agreement with the data. From these findings, we extract design principles for simultaneous optimization of charge transfer resistance and interface quality to maximize the photovoltage of metal-oxide protected MOS water splitting devices.
[1] Y.W. Chen, et al. Nature Mat. 2011, 10, 539-544.
[2] A. G. Scheuermann, et al. Energy Environ. Sci. 2013, 6, 2487–2496.
[3] S. Hu, et al. Science 2014, 344, 1005−1009.

Figure 1 | Charge transfer in three cell types for water splitting applied to silicon: The Type 0 Semiconductor-Liquid (SL), Type 1 Metal-Insulator-Semicondcutor (MIS), and Type 2 p+n junction. The density of states on either side of the oxides and the excition splitting position with respect to these layers play a crucial role in mediating efficient charge transfer. These effects are so strong that Type 0 protected silicon cells exhibit essentially no photovoltage, Type 1 nSi cells show a linear photovoltage loss with oxide thickness, and Type 2 cells--where the hole concentration on the Si/SiO2 interface is always high--exhibit record photovoltages at all oxide thicknesses and pH values studied.

Figure 1
Improving Graphene Conductivity through Selective Atomic Layer Deposition
Authors: Liu Chanyuan , Han Xiaogang , Bao Wenzhong , Pearse Alexander J , Hu Liangbing , Rubloff Gary W 
Published: February 2020

One of the most promising approaches for massive production of transparent conducting electrodes (TCE) is roll-to-roll printing of graphene flakes solution. However, graphene flakes inevitably contain structural defects like grain boundaries and dislocations, together with macroscopic defects such as wrinkles and cracks during transfer. In addition, the printed flakes can’t align with each other perfectly. All these defects and the gaps between detached flakes hinder electrical transport and limit the mechanical strength and reliability of the graphene.
Here we report a technique to electrically heal and connect graphene flakes via selective atomic layer deposition (ALD) of conductive materials. We have demonstrated selective growth of ALD aluminum-doped zinc oxide, ruthenium and platinum on pristine graphene surface prepared from exfoliated highly ordered pyrolytic graphite (HOPG). ALD materials nucleate on graphene cracks and edges but exhibit a significant nucleation barrier on intact basal planes due to the chemical inertness from delocalized π-orbitals. We also present a high-throughput fabrication method to create graphene patterns via metal shadow mask and O2 plasma. This model system of patterned CVD graphene islands demonstrates electrical connection of separated graphnene flakes by selective ALD processes. In addition, shadow-mask-patterned CVD graphene field effect transistors (FETs) are used to monitor graphene carrier density and mobility variation after ALD growth. We found considerable carrier density and conductivity increase of a single graphene flake after V2O5 ALD, which can be explained by p-doping of graphene due to the high work function V2O5.
New Insights into Sequential Infiltration Synthesis
Authors: Elam Jeffrey W , Biswas Mahua , Darling Seth , Yanguas-Gil Angel , Emery Jonathan D. , Martinson Alex B. F. , Nealey Paul F. , Segal-Peretz Tamar , Peng Qing , Winterstein Jonathan , Liddle J. Alexander , Tseng Yu-Chih 
Published: February 2020

Sequential infiltration synthesis (SIS) is a process derived from ALD in which a polymer is infused with inorganic material using sequential, self-limiting exposures to gaseous precursors. During the initial SIS cycles, the organometallic precursor (e.g. trimethyl aluminum, TMA) reacts preferentially with specific functional groups within the polymer, while in later cycles growth occurs in an ALD-like fashion on the inorganic “seeds” that have been planted inside the polymer. Consequently, it is possible to start with a blend of two polymers, such as a diblock coplymer, and selectively infuse just one of the two components. As a result of this selective, step-wise infusion, SIS can create novel composites with intermediate or even unique properties compared to those of the pure polymeric and inorganic constituents. Alternatively, the organic component can be removed through oxidation leaving a purely inorganic material, but with a mesostructure that mimics that of the starting polymer. One particularly attractive application for SIS is lithography: SIS can harden polymer resists rendering them more robust towards subsequent etching, and this permits deeper and higher-resolution patterning of substrates such as silicon. With this objective in mind, we have performed a series of investigations using in-situ Fourier transform infrared absorption spectroscopy (FTIR), in-situ synchrotron grazing incidence small angle X-ray scattering (GISAXS), and high resolution scanning transmission electron microscope (STEM) tomography of a model system: Al2O3 SIS using TMA and H2O within the diblock copolymer, poly(styrene-block-methyl methacrylate) (PS-b-PMMA). While the picture is far from complete, these studies reveal some important details: 1) TMA adsorption on PMMA occurs through a weakly-bound intermediate; 2) the SIS kinetics are diffusion-limited, but desorption is 10x slower than adsorption; 3) dynamic structural changes occur during the individual precursor exposures. All of findings impact the resulting composite, and hence will dictate the success of the lithography.

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(Invited) Selective Etch of Si and SiGe for Gate All-Around Device Architecture
Authors: Wostyn Kurt , Sebaai Farid , Rip Jens , Mertens Hans , Witters Liesbeth , Loo Roger , Hikavyy Andriy Yakovitch , Milenin Alexey , Horiguchi Naoto , Collaert Nadine , Thean Aaron , Mertens Paul W. , De Gendt Stefan , Holsteyns Frank 
Published: February 2020

The next era in CMOS technology scaling seeks not only to introduce SiGe or Ge [1] but also aims at replacing the FINFET technology by a gate all around concept, requiring selective removal of Si1-xGex to Si1-yGey(with 0 ≤ x, y ≤ 1). Gate All-Around (GAA) integration schemes are investigated for improved short channel control. In this paper we will show how alkaline solutions can be used for selective etch of Si and SiGe up to 50% and that the alkaline etch behavior of SiGe is not merely an extension of Si, even at low to moderate Ge concentrations (Ge ≤ 50%).
The exponential decrease in alkaline etch rate of SiGe with increasing Ge concentration enables the selective removal of Si to Si0.75Ge0.25. [2] Alkaline etching of Si has been studied extensively and is very well understood. [3] The oxidation of Si by water is catalyzed by the hydroxyl anion and results in anisotropic etch properties. The Si (001) and (110) directions etch much faster compared to the Si (111) crystallographic planes. The alkaline dissolution mechanism of SiGe is much less studied and understood.
Figure 1 shows a Si-Si0.75Ge0.25 multilayer stack after alkaline selective etch in 5% TMAH at 60¢ªC. The stack was made by FIN patterning of an epitaxial Si0.75Ge0.25 / Si / Si0.75Ge0.25 / Si multilayer. The TEM picture shows the complete removal of the top Si layer. The selective etch of the Si layer sandwiched between two Si0.75Ge0.25 layers is limited by the slowly etching Si (111) planes, resulting in the formation of inverted pyramids. Figure (1) shows that the Si0.75Ge0.25 layer is also limited by the (111) crystallographic planes. The shape of convex corners results from the crystallographic planes with the highest etch rate. [4] The pyramidal shape of the Si0.75Ge0.25 layer indicates that the Si0.75Ge0.25(111) plane etches faster than (110). This is very different from Si where (111) planes etch much slower than the (110) planes.
In this paper we will show how SiGe (Ge ≤ 50%) alkaline etching behaves differently compared to Si and its implications to Si or SiGe selective etch. In addition we will show how improper control of process conditions can change SiGe etching from anisotropic to isotropic.
[1] M.L. Lee et al. Appl. Phys. Rev. 97 (2005) 011101.
[2] Seidel et al. J. Electrochem. Soc. 137 (1990) 3626.
[3] M.A. Hines, Annu Rev Phys Chem 54 (2003) 29-56.
[4] P. Pal et al. J. Micromech. Microeng 17 (2007) R111-R133.

Figure 1
Investigation of Silver Oxide Electrochemical Behavior to Improve Silver-Zinc Battery Rechargeability
Authors: Ortega Jeffrey Vincent , Dueber Ross Eugene , Renkin Troy William 
Published: February 2020

Cyclic voltammetry and galvanostatic cycling experiments where performed on silver thin films in conjunction with a quartz crystal microbalance (QCM) to identify the intermediate species and mass transport properties at the surface of a silver cathode in the presence of gelled aqueous electrolyte. Scanning electron microscopy (SEM) was then employed to characterize the physical effects from changing the discharge rates and the state-of-charge. The use of additives on the surface and in the electrolyte was also explored and characterized. The results were then utilized in silver-zinc rechargeable button cell batteries and tested for increased electrode utilization, charge rate capability, and cycle life improvement.
A Prototype Rechargeable Aluminum Battery
Authors: Guo Juchen , Geng Linxiao , Lv Guocheng , Xing Xuebing 
Published: February 2020

Although Lithium-ion battery technologies have made significant positive impact on portable electronics and electric vehicle industries, the feasibility of wide deployment of lithium-based batteries for land-based renewable energy storage and grid applications may be questionable due to the limited lithium resource, the resource geographic distribution, and the cost of lithium mining and recycling. Therefore, alternative rechargeable battery technologies based on abundant elements need to be developed for sustainable energy storage. Among the potential candidates, aluminum (Al) may be the ultimate choice as the anode material: Al is not only the most abundant metal in earth’s crust, but also has attractive capacity due to its trivalency. Al has the second highest specific capacity of 2980 mA h g-1 (Li has 4634 mA h g-1) and the highest capacity density of 8046 mA h cm-3 (Li has 2456 mA h cm-3) among all metal anodes. To date, there were only scarce investigations on rechargeable Al batteries with little success. For the first time, we demonstrate a new prototype rechargeable Al battery comprised of Chevrel phase molybdenum sulfide (Mo6S8) as the intercalation-type cathode, Al metal as the anode, and a mixture of AlCl3 and 1-butyl-3-methyimidazolium chloride (AlCl3-[BMIm]Cl) as the electrolyte. The Mo6S8 cathode shows unambiguous electrochemical activity for reversible Al intercalation and extraction and good cycle stability. The chronopotentiometric plateaus in Al-Mo6S8 charge-discharge curves indicate phase-transition type of electrochemical reactions. In addition to the electrochemical analysis, XRD studies provide the crystallographic information of the Al intercalated Mo6S8. We conclude that the theoretical chemical formula of fully Al intercalated Mo6S8 is Al2Mo6S8 with Al occupying two different sites in the Mo6S8 crystal lattice. The theoretical material-level specific energy of the Al-Mo6S8 battery is approximately 90 Wh kg-1 (assuming 0.5 V nominal voltage), which makes this new rechargeable battery technology an attractive alternative for large-scale sustainable energy storage.
Design & Development of Powerful Next Generation Layered Cathode Materials for Na-Ion Batteries
Authors: Buchholz Daniel , Keller Marlou , Vaalma Christoph , Passerini Stefano 
Published: February 2020

Sodium-Ion Batteries (SIBs) have established themselves as possible low-cost alternative to the common lithium-ion battery (LIB). The cost advantage is underlined by a powerful electrochemical performance, superior to any other secondary battery except for LIBs. Consequently, this has led to a rapidly increasing scientific interest within the last five years. In accordance with the economical concept of diversification SIBs are discussed to be promising alternative for applications, in which cost-efficient energy storage (in terms of $/kWh) is the most important criterion. In order to boost SIBs into such applications (e.g. for the decentralized and fragmented power grid of the future) new, powerful but also rather cheap materials composed of abundant and environmentally friendly elements, need to be used in order to cover the lower electrochemical performance. In fact, research community and research efforts are, currently, focusing on the material screening and development. [1-3]
With respect to layered materials strong progress in terms of their understanding, characterization and their performance has been achieved. In this presentation we will focus on the design and development of layered cathode materials for powerful next generation SIBs.
In the past, we have synthesized and characterized layered P2- NaxNi0.22Co0.11Mn0.66O2material. [4-6] In this presentation we will show how the composition of this material can be modified and reveal the effect on the electrochemical performance.[7-9] Final intention of the presentation is to:
-illustrate the influence of the composition on the electrochemical performance,
-illustrate how layered cathode materials can be designed,
-demonstrate the feasibility of these principals via a new layered Na- based oxide.
The final material delivers a stable capacity of about 110 mAh g-1 (3.4 V average discharge potential) at a high current rate of 1C (180 mA g-1) between 4.3-2.5 V (vs. Na/Na+) in conventional organic carbonate based electrolyte. This performance is among the best reported for layered Na-based oxides so far and certainly is promising for the application in future Na-based electrochemical energy storage devices.
[1] S.-W. Kim et al. Adv. Energy Mater. 2 (2012), 710.
[2] J.M. Tarascon Nature Chemistry 2 (2010), 510.
[3] N. Yabuuchi et al. Chem. Rev. 114 (2014), 11636.
[4] D. Buchholz et al. Chem. Mater. 25 (2013), 142.
[5] D. Buchholz et al. J. Mater. Chem. A 2 (2014), 13415.
[6] L.G. Chagas et al. J. Mater. Chem. A 2 (2014) 20263.
[7] I. Hasa et al. Adv. Energy Mater. 4 (2014), 140083.
[8] I. Hasa et al. ACS Appl. Mater. Interfaces 7 (2015), 5206.
[9] D. Buchholz et al. J. Power Sources 282 (2015), 581.
Applying Reconfigurable Networks of Charge-Transporting Polycyclic Aromatic Hydrocarbons to Problems in Energy Storage
Authors: Helms Brett A. , Frischmann Peter D. , Gerber Laura C. H. , Doris Sean E. , Fan Frank , Chiang Yet-Ming , Jain Anubhav , Qu Xiaohui , Persson Kristin A 
Published: February 2020

I will report our recent work in understanding and controlling adaptive charge-transport behaviors in reconfigurable molecular networks of polycyclic aromatic hydrocarbons in non-aqueous electrolytes. This will include a detailed look into their network forming ability as a function of concentration, temperature, and imposed state of charge. Their application as embedded 3-D redox mediators will be discussed in the context of a hybrid Li-S redox flow battery. The design of our network-forming redox mediators was informed by a new high throughput computational platform developed by our team, where we can selectively amplify or dampen electronic charge transport at specific stages in a charge or discharge sequence.
Catholyte Development for Non-Aqueous Redox Flow Batteries
Authors: Zhang Lu , Huang Jinhua , Shkrob Ilya A , Brushett Fikile R. , Wei Xiaoliang , Burrell Anthony K. , Cheng Lei , Curtiss Larry , Duan Wentao 
Published: February 2020

Non-aqueous redox flow battery is a promising large scale stationary energy storage technology. Unlike traditional battery systems, the active energy storage material is in mobile phase and stored in external tanks. The energy and power of RFBs thus can be decoupled and independently scaled, which offers remarkable design flexibility for applications with various energy-to-power ratios.
Material development for this technology is crucial for practical implementation. Molecular engineer of organic redox active molecules could lead to tunable physical and electrochemical properties, including solubility in organic solvents, molecular mobility, redox potential, and electrochemical reversibility, which are key factors to energy storage applications. The dimethoxybenzene based catholyte molecules have been systematically developed and evaluated towards various purposes. For instance, ANL-8, ANL-9 and ANL-10 molecules were developed by incorporation of PEO chains with different lengths on one or both sides of the dimethoxy-di-tert-butyl-benzene based redox structure in order to afford higher solubility. Another category of the molecules, including JH-100 and JH-200, were developed by striping down the non-essential structures, such as tert-butyl groups and ether chains, in order to boost the intrinsic capacities. While many of these molecules can afford electrochemically reversible behavior, some new promising features are discovered. ANL-8 and ANL-9 molecules are found to be liquid at room temperature, which was hoped to function as co-solvent for NRFBs, thus leading to much improved energy density. JH-100 and JH-200 molecules, on the other hand, offer much enhanced intrinsic capacity (nearly two times as big as DBBB), which also is believed to be a key to further improve the energy density and lower the cost of NRFBs.