bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanoimprinting of Woodpile Electrodes for 3D Lithium-Ion Microbatteries with Both High Capacity and Power
Authors: Li Wenhao , Zhou Yiliang , Howell Irene , Gai Yue , Carter Kenneth R. , Watkins James J. 
Published: February 2020

The trend of device downscaling drives the corresponding need for power source miniaturization. With footprint area being the determinant form factor for on-chip battery systems, enhancement of areal energy and power density is urgently needed. Due to the 2D configuration limit, it is impractical for a conventional thin film battery to possess high capacity and power simultaneously.
Here, we show that a novel 3D woodpile electrode, made from TiO2 nanoparticles using solvent-assisted nanoimprint lithography (NIL), can remarkably enhance both the capacity and power of a lithium-ion battery (LIB). With the convenience of sequential imprinting, woodpile electrodes of different heights are readily made in a “stack-up” manner, resulting in a proportional increase of capacity, which is hard to achieve in thin film batteries. Little evidence of specific capacity decrease was observed as the structure height increased by stacking additional layers. These 3D electrodes boast superior rate performance with 1.5- to 6-fold improvement of the specific capacity (compared to 2D counterpart) during fast cycling (up to 15 C) due to the structure’s large surface area. The TiO2 woodpile proved to be a strong candidate for the anode of a high-performance LIB. More importantly, this work demonstrates the great potential of NIL as a platform to create high density architectures for energy storage devices. The strategy described here can be potentially expanded to other electrochemical systems.
Effects of Chemically-Introduced Structures on Near Infrared Photoluminescence of Locally Functionalized Single-Walled Carbon Nanotubes
Authors: Shiraki Tomohiro , Shiraishi Tomonari , Onitsuka Hisashi , Juhász Gergely , Nakashima Naotoshi 
Published: February 2020

Semiconducting single-walled carbon nanotubes (SWNTs) show near infrared photoluminescence (NIR PL) based on the Van Hove singularity in the one-dimensional structures. Recently, PL enhancement with wavelength shifts of the SWNTs has been reported through a very limited amount of chemical modification by oxygen atom doping and sp3 defect doping on the sp2networks.[1-3] In this study, we have examined modulation of the PL properties from a view point of structural design of the modified sites on the local-f-SWNTs using designed molecules.[4,5]
Bisdiazonium compounds (2Dz) are newly synthesized and we find that the local-f-SWNTs using 2Dz (SWNT/2Dz) shows new red-shifted PL.[4] Namely, the emission peak appears at 1256 nm which is remarkably red-shifted than those of pristine SWNTs (985 nm) and mono-functionalized SWNTs (SWNT/1Dz, 1129 nm), as shown in Figure. It is considered that the chemical modification using 2Dz provides an emissive site with a narrower band gap on the SWNTs owing to local dissociation of a degenerate energy band through modification-induced symmetry breaking of the SWNT. Moreover, wavelengths of the new PL are changed with dependence of the methylene linker length of 2Dz.
Other structural factors for PL modulation of local-f-SWNTs will be presented at the meeting.

References: [1] Weisman, R. B. et al., Science
2010, 330, 1656-1659. [2] Wang, Y. et al., Nat. Chem.
2013, 5, 840-845. [3] Nakashima, N. et al., J. Phys. Chem. C
2016, 120, 15632-15639. [4] Nakashima, N. et al., Sci. Rep.
2016, 6, 28393. [5] Nakashima, N. et al., Chem. Commun.
2016, 52, 12972-12975.

Figure 1
(Invited) Toward the Electrochemical Growth of Single-Walled Carbon Nanotubes from Ambient Carbon Dioxide
Authors: Douglas Anna , Carter Rachel E. , Pint Cary L. 
Published: February 2020

To address the rising levels of CO2 in the atmosphere, the conversion of CO2 into secondary chemicals and materials offers the most economically viable approach to solve this global challenge. However, state-of-the-art efforts to convert CO2 into low-value commodities and fuels, such as methanol, suffer from low efficiencies, low value of the commodity, and expensive catalysts and processes. Here we discuss an alternative approach where CO2 is captured in a molten carbonate medium from air, and split into its elemental constituents in the presence of a catalytic electrode surface to form carbon nanotubes (CNTs). This general approach was developed in the 1960's for the deposition of carbon, [1-2] and recently shown to be adapted without composition control of bulk catalytic electrodes to the growth of large-diameter (> 100 nm) CNTs [3]. Here, we demonstrate the ability to rationally engineer the anode and cathode electrodes to controllably tune the catalytic material composition and size during the production of CNTs using this technique. This relies on existing knowledge of advances in the gas-phase synthesis of CNTs applied to this electrochemical system, where it is known that iron is the most catalytically active catalyst material, and that catalyst nanoparticle size controls the diameter of the grown CNTs. We show the ability to engineer the material composition of the electrodes to produce high yield (> 99%) growth of multi-walled CNTs with tight diameter ranges averaged < 30 nm, and we show that control on catalytic nanoparticle size can decrease this average diameter to even smaller CNTs. Most notably, early results indicate a minority presence of few-walled and single-walled CNTs, and we present a vision where the ability to transfer the mechanisms studied and understood for single-walled CNT growth over the past few decades can drive rapid forward progress in producing high quality single-walled CNTs in both tangled and aligned architectures using this technique. This paves a pathway to produce a material that prominent researchers for the past few decades have envisioned to revolutionize our modern world, with a precursor material derived from air that poses a significant long-term global threat to mankind.
References:
[1] B.B.M.D. Ingram and G.J. Janz, Electrochim Acta, 11, 1629 (1966)
[2] H.Y. Yin, X.H. Mao, D.Y. Tang, W. Xiao, L.R. Xing, H. Zhu, D.H. Wang, and D.R. Sadoway, Energ Environ Sci, 6, 1538 (2013).
[3] S. Licht, A. Douglas, J. Ren, R. Carter, M. Lefler, and C.L. Pint, ACS Cent Sci, 2, 162-168 (2016).
Multi-Modal Spectroscopic and Microscopic Characterization of Thin-Film Networks of Semiconducting Carbon Nanotubes
Authors: Jones Andrew Crandall , Kearns Nicholas M , McDonough Thomas J , Zanni Martin 
Published: February 2020

Thin-film distributions of semi-conducting carbon nanotubes (CNTs) exhibit potential as a candidate material for photovoltaic devices due to their strong absorption throughout the solar spectrum and exceptional transport properties. Despite this potential, characterization of the systemic parameters which determine and limit photovoltaic performance has remained a challenge. To this end, multidimensional spectroscopic methods represent a valuable tool in identifying and describing the energetic pathways in these systems which contribute to device performance.
In this presentation, we demonstrate the development of a broad bandwidth (500-1300 nm), high-repetition rate (100 kHz) 2-dimenstional electronic spectroscopy (2D-ES) system capable of high-speed, low noise spectroscopic characterization of the energy transfer pathways. The diagonal and cross-peaks measured in 2D-ES measurements provide critical information about the dephasing time, correlation, and couplings between electronic states. The high acquisition rate of our measurement system enables us to monitor multiple detection pathways, limited not only to optical absorption, but also measurement of the photo-induced current allowing for direct spectroscopic characterization of the energy pathways taken by carriers contributing to photocurrents.
In addition to traditional far-field spectroscopic characterization, in which the response of a macroscopic area (10's of μm2) is collected, we further show the use of our broadband source in microscopic spatial mapping of device response. Through combination with atomic force microscopy of the nanoscopic structure of a surface, we demonstrate the ability to characterize and correlate the topology of a surface with a specific optical response.
Unique Architectural Fidelity of C60-Decorated Flavin-Wrapped Nanotubes
Authors: Papadimitrakopoulos Fotios , Karunaratne Erandika , Mollahoseini Mehdi , Gascon Jose 
Published: February 2020

One of the greatest challenges with single-walled carbon nanotube (SWNT) photovoltaics and nanostructured devices is maintaining the nanotubes in their pristine state (i.e. devoid of aggregation and inhomogeneous doping) so that their unique spectroscopic and transport characteristics are preserved. To this effect, the tight helical wrapping of flavin derivatives around SWNTs presents an ideal vehicle for individualizing SWNTs, while at the same time affording the incorporation a variety of substituents that can be brought within π-π overlap to the graphene sidewalls (Figure 1a). C60-functionalized flavin composed of PCBM and isoalloxazine moieties attached on either ends of a linear, C-12 aliphatic spacer forms a concentric assembly where transient absorption spectroscopy have shown the effective photoinduced charge transfer quenching of the encased SWNTs. In this contribution, we present convincing evidence on the exact location where the C60 moiety resides. As shown before1, the isoalloxazine helix is partitioned into a co-spiral electronegative uracil groove (Figure 1b) and an electropositive o-dimethylphenyl (phenyl) groove (Figure 1c). Spectroscopic investigation alongside with modeling of the diameter-dependence ES
ii
redshifts suggests that the C60 moiety is solely localized within the uracil grooves (Figure 1b) due to improved electrostatic interactions. This indicates the profound assembly fidelity of FMN-wrapped nanotubes, which rivals that of biological helices.

1 M. Mollahosseini, E. Karunaratne, G. N. Gibson, J. A. Gascón, F. Papadimitrakopoulos, "Fullerene-Assisted Photoinduced Charge Transfer of Single-Walled Carbon Nanotubes through a Flavin Helix", J. Am. Chem. Soc.
2016, 138, 5904−5915.

Figure 1
5Wh Class Planar Sodium Nickel Chloride (Na-NiCl2) Battery Operated at below 200oc for Grid Scale Energy Storage
Authors: Jung Keeyoung , Park Yoon-Cheol , Son Sori , Lee Younki , Kim Chang-Soo , Jin Dana , Shim Wooyoung , Chang Hee Jung , Li Guosheng , Sprenkle Vincent 
Published: February 2020

Sodium nickel chloride (Na/NiCl2) battery is one of the most promising candidates as a large scale electrochemical energy storage device. The battery comprises molten Na and NiCl2 as negative and positive electrodes, respectively, in its charged state, separating them by a β”-Al2O3 solid electrolyte (BASE). In order to facilitate fast sodium ion transport in the cathode compartment, molten NaAlCl4, as a secondary electrolyte (or catholyte), is infiltrated into the cathode materials powder. The battery typically operates at 250~300oC so as to maximize the ionic flux in the NaAlCl4 and through the solid electrolyte, and to minimize the dissolution of NiCl2into the melt. However, this efficient battery is yet to be widely used in grid scale energy storage applications since it is still expensive and hard to dramatically reduce the cell price mainly due to its use of expensive sealing technologies.
The presentation introduces Korea-US collaborative efforts to develop a lower temperature operating sodium beta-alumina battery (LT-NBB) with a Na/NiCl2 chemistry. Since the novel battery runs at below 200oC, it can be fabricated at an ultra low manufacturing cost by introducing a new planar cell design with a greatly reduced number of cell components, and by eliminating expensive conventional sealing technologies. Enhanced degradation resistance of cathode materials is another important advantage of this technology. In this presentation, challenges and progress in building 5Wh class prototype LT-NBB cells using BASE with 70 mm in diameter will be discussed.

Figure 1
Effect of Artificial Seawater on Passivation of Ti
Authors: Yan Shaokun , Song Guang-Ling , Zheng Dajiang , Dargusch Matthew , Zhou Lian 
Published: February 2020

Titanium is well known for its high corrosion resistance. It may be used in the marine industry. In this study, the passivation behavior of titanium was investigated in artificial seawater. It was found that some anions in the artificial seawater could influence the passivation current densities of Ti. The anodic current peak at around 1.6V/SCE on the passivation curve could be associated with dissolution of the passive film. Oxygen evolution could occur at an even more positive potential. The surface films formed at different potentials exibited different biofouling performance.
The Mixed Potential Model for the Passive State and Hydrogen Evolution Reaction of AA2098-T851
Authors: Macdonald Digby D. , Ghanbari Elmira , Saatchi Alireza 
Published: February 2020

Theoretical and experimental investigations for fundamental understanding of the passivation process and its kinetics could lead to the prediction of the electrochemical behavior of the third-generation Al-Li alloy 2098. In this paper, the kinetics of the passive film formation on AA2098-T851 in 0.1M NaHCO3 in a CO2 atmosphere at 25°C, at potentials with both metal dissolution and hydrogen evolution reaction (HER) was investigated. This was done by performing electrochemical impedance spectroscopy (EIS) on the passive layer after each potentiostic steps in the anodic direction that followed by stepping in the opposite direction. The optimization of the EIS data was done by applying the previously developed Mixed Potential Model (MPM) that considers the Point Defect Model (PDM) for dissolution and passivation of the metal along with the Butler-Volmer equation for the cathodic reaction. It was shown that the inequality of certain kinetic processes of passive layer formation leads to the irreversibility of the metallic passivation in opposite potential scanning directions. Also, considering that the hydrogen evolution reaction incorporates quantum mechanical tunneling of the charge carriers through the barrier oxide layer on the passive metal surface, a cathodic Tafel constant (βc
) was calculated. The estimated βc
was in accord with the predicted value for the HER according to the slow discharge of protons mechanism.
(Invited) Past, Present, and Future of High-k/Metal Gate Technologies
Authors: Iwai Hiroshi 
Published: February 2020

The SiO2 based gate insulator and poly Si gate electrode had been used almost 4o years for (C)MOS integrated circuits from 1970 to 2010 because of their extraordinary good properties of both the interfaces at the substrate and gate electrode. Thus, most of the people had not believed the replacement of SiO2/poly Si gate stack by that of high-k/metal in the products would be impossible, although the demand to introduce the high-k gate oxide became stronger due to the high tunneling gate leakage current when decreasing the gate oxide thickness with the scaling. However, the operation of high k/metal gate stack MOSFETs were demonstrated by several different organizations at the same time at IEDM 1999. Since then, many R & D organizations seriously participated to the research and development of high-k/metal gate stack for MOSFETs. It was in 2001, when Prof. Samares Kar proposed to create an ECS symposium on “Physics and Technology of High-k Gate Dielectrics”. Then, the 1st symposium was held in Salt Lake City, Utah, U.S.A. on October 20-14, 2002. At that time total number of the presentations at the symposium was 34. The, number increased to 56 in the 2nd symposium in Cancun, Mexico, 2003, and 75, in the 3rd symposium in Los Angeles, in 2006, and so on. In 2007, Intel introduces HfO2 based high-kmaterial for the 1st time into their product. Later, the symposium was renamed with Semiconductors, dielectrics and metals for Nanoelectronics and still continues and contributed to give opportunities to the researchers and engineers for the paper presentation and discussion. Prof. Samares Kar has been the leading organizer of the symposium, maintaining rigorous standards to make the symposium one of the most successful in ECS. However, it was very sad that Prof. Samares Kar passed away on January 13, 2017 at his home in Kolkata, India. We would like to express our sincere appreciation for the hard work and rigorous drive towards the advancement of the symposium by giving presentations for the past, present and future of high-k stack technologies.
(Invited) Interface Engineering for Nanoelectronics
Authors: Hacker Christina A. , Bruce Robert C , Pookpanratana Sujitra 
Published: February 2020

The pace of innovation within the electronics industry is picking up steam in response to critical challenges as conventional silicon technology matures. Increasingly, semiconductor-based systems, from small sensors to high performance computers, or everything in between, must maximize performance, while minimizing energy use and providing security and assurance. As recently highlighted in “Semiconductor Research Opportunities” by the SIA/SRC, for the semiconductor industry to continue achieving performance improvements, the broader research community needs a comprehensive approach that considers all aspects of semiconductor technology, including novel materials, new manufacturing techniques, new structures, system architectures and applications.
Among these approaches is the fundamental understanding of electronic processes at interfaces since the interface increasingly dominates electronic performance. I will describe advances made in our ability to manipulate and measure organic and molecular interfaces at the nanometer scale and the impact on the resulting electronic performance. This talk will contain three primary themes, 1-designer interfaces, 2-electronic junction formation, and 3-advancing metrology for nanoelectronics. The foremost step of interface engineering is the ability to create designer surfaces where monolayers can be tailored for specific electronic properties. This can be achieved by controlling the tunnel barrier thickness on a ferromagnetic electrode or by using click chemistry to create dense, high-quality electrically active molecular layers. Understanding the electrical response on the nanoscale is non-trivial as often creating the test structure creates artifacts that dominate the electronic response. In particular, I will focus on the measurement advances made in molecular electronics, highlighting our understanding of the interface science and characterization.
Hole-Doping Induced Ferromagnetism in Monolayer SnO: A First-Principles Study
Authors: Houssa Michel , Iordanidou Konstantina , Pourtois Geoffrey , Afanas'ev Valery V , Stesmans Andre 
Published: February 2020

Two dimensional (2D) materials are currently attracting considerable interest due to their promising applications in future nanoelectronic devices. Magnetic 2D materials are also gaining attention, for their possible use in novel spintronic devices [1]. Recently, hole-doping in monolayer SnO has been theoretically predicted to induce a paramagnetic to ferromagnetic phase transition in this 2D material, for a typical hole density of about 5x1013/cm2 [2]. Magnetism in monolayer SnO arises from an exchange splitting of electronic states at the top of the valence band, where the density of states exhibits a sharp van Hove singularity, resulting in a so-called Stoner (magnetic) instability [2]. This behavior is typical of materials with “Mexican-hat” energy band edges (as predicted for the valence band edge of monolayer SnO), and has also been predicted in e.g. monolayer GaSe [3].
In this work, the possibility to induce hole doping in monolayer SnO by intrinsic and extrinsic defects is investigated, using first-principles simulations, based on density functional theory. It is found that Sn vacancies generate spin-polarized gap states near the valence band edge of monolayer SnO, and that these point defects are behaving like acceptors. A typical density of 5x1013/cm2 of Sn vacancies induces a paramagnetic to ferromagnetic phase transition in the material, with a magnetic moment density of 1 Bohr magneton/hole. Substitutional doping of Sn atoms by e.g. In or Zn atoms is also predicted to result in hole-doping of monolayer SnO, and also leads to a ferromagnetic order in the 2D material. The possibility to induce a ferromagnetic phase transition in monolayer SnO by electrostatic doping will also be discussed.
[1] W. Han, APL Mater. 4, 032401 (2016).
[2] L. Seixas et al., Phys. Rev. Lett. 116, 206803 (2016).
[3] T. Cao et al., Phys. Rev. Lett. 114, 236602 (2015).
(Invited) Microcalorimetric Investigation of Cu Underpotential and Bulk Deposition – a Direct Access to Anionic Side Processes and Reaction Steps
Authors: Schuster Rolf , Frittmann Stefan 
Published: February 2020

Measuring the heat during electrochemical reactions provides direct information on the reaction entropy of the electrochemical processes. These include also charge neutral side processes, e.g., coadsorption of anions with metal ions or ordering processes of the solvent at the interface, which will not show up in the electrochemical charge balance. Electrochemical microcalorimetry hence provides complementary information to the current voltage relationship as measured by conventional electrochemical techniques and may allow for the identification of side processes often obscured in electrochemical systems (1, 2). In this presentation we will present two examples, i) we will investigate anionic side processes during the Cu UPD formation on Au(111) in the presence of sulfate (3) and ii) we will address the reaction steps and the role of Cu+during the Cu-bulk deposition.
For Cu UPD it is well accepted that Cu deposition is accompanied by strong coadsorption of anions. From the course of the reaction entropy and the charge balance during the UPD process we determined the potential dependent anion coverages. From experiments with pH variation it followed that sulfate and bisulfate become adsorbed with roughly equal amounts. In addition we found highly positive reaction entropy upon the completion of the first metal monolayer, which signals a charge neutral substitution process of adsorbed anions by oxygenated species.
During pulsed Cu-bulk deposition we found that the heat evolution continues after the current pulse, i.e., without external current flow (see figure). This directly signals Cu deposition from Cu+ followed by a slow reestablishment of the Cu+/Cu2+ equilibrium, in agreement with the reaction mechanism of Mattsson and Bockris, proposed on the basis of the Tafel plot (4).
References:
1. S. Frittmann, V. Halka, C. Jaramillo and R. Schuster, Rev. Sci.
Instrum., 86, 064102 (2015).
2. S. Frittmann, V. Halka and R. Schuster, Angew. Chem. Int. Ed., 55, 4688 (2016).
3. S. Frittmann and R. Schuster, The Journal of Physical Chemistry C, 120, 21522 (2016).
4. E. Mattsson and J. O. M. Bockris, Transactions of the Faraday Society, 55, 1586 (1959).

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