bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Surface Science Aspects of Etching with Atomic Scale Fidelity
Authors: Lill Thorsten , Kanarik Keren J. , Tan Samantha S.H. , Shen Meihua , Pan Yang , Marks Jeffrey , Vahedi Vahid , Gottscho Richard A. 
Published: February 2020

As the IC industry approaches devices with half pitches below 10 nm, etching requires atomic scale fidelity because the device dimensions and their allowed tolerances are of the same order of magnitude as the inter-atomic distances in the crystal lattice. Atomic Layer Etching is emerging as a solution and plasma assisted or directional ALE is being adopted in the manufacturing of integrated devices /1/.
Separation of the etching process into single unit processes allows to apply the large body of knowledge in surface science to improve fundamental understanding. In this talk we will focus on the fundamental processes at the wafer surfaces during etching of various materials with different ALE approaches. Strategies to obtain low physical and chemical surface damage will be presented.
1. K.J. Kanarik, T. Lill, E. Hudson, S. Tan, S. Sriraman, J. Marks, V. Vahedi, R.A. Gottscho; J. Vac. Sci. Technol. A 33, 020802 (2015)
Proton Inserted SiO2 Dielectrics for Nonvolatile Memory-Thin Film Transistor
Authors: Jang Jin Nyoung , Yun JangWon , Hong MunPyo 
Published: February 2020

We demonstrated the nonvolatile memory functionality of both nano-crystalline silicon (nc-Si) and amorphous indium gallium zinc oxide (a-IGZO) field effect transistors (FETs) using mobile protons that are generated by very short time (within 5 minutes) hydrogen neutral beam (H-NB) treatment at room temperature (25 °C). Some researches try to hydrogen insertion process via long time (40 minutes) high-pressure hydrogen annealing (HPHA) at high temperature (400 °C) that also need several steps such as poly silicon deposition, HPHA process, and poly silicon etching process. However our hydrogen insertion process does not need any other additional process but only H-NB process during normal thin film transistor fabrication. Also the whole memory fabrication process kept under 50 °C (except SiO2 deposition process; 300 °C). These NVM-TFT(nc-Si and a-IGZO) and devices exhibited reproducible hysteresis, reversible switching, and nonvolatile memory behaviors in comparison with those of the conventional FET devices. We also investigated neutral beam energy effect on non-volatile memory functionality with IGZO NVM-TFTs. The hysteresis widths of the IGZO NVM-TFTs exhibited strong linear dependency on the H-NB treatment energy. We expected this result from the energy dependent hydrogen surface density profile. The sandwiched hydrogen between insulators becomes mobile proton without annealing process. This H-NB dependent mobile proton density variation is meaningful because until now the only way to increase proton density was increasing ambient temperature or annealing time. The hydrogen neutral beam process between insulators to generate mobile proton is easily controlled by reflector bias. Our study will further provide a useful route of creating memory functionality and incorporating proton-based storage elements onto a probability of next generation flexible memorable electronics such as low power consumption flexible display panel.

Figure 1
Perfect Separation of Hybrid Orientation Structure of CeO2(100) and (110) Regions Grown on SOI Substrates with Lithographically Formed Trenches
Authors: Inoue Tomoyasu , Shida Shigenari 
Published: February 2020

Using magnetron sputtering with low energy electron beam irradiation, epitaxial growth of CeO2 layers on Si(100) substrates has been studied for the application to microelectronics. We have found that orientation selective epitaxial (OSE) growth of　 CeO2(100) and (110) layers on Si(100) is capable by controlling surface potential distribution. With the aim of application to hybrid orientation technology for higher speed CMOS devices, we are studying the hybrid orientation structure of the CeO2(100) and (110) regions on Si(100) substrates using electron beam-induced OSE growth by reactive magnetron sputtering. Two separate areas of growth are seen, with CeO2(100) layers found to grow in areas irradiated by electrons during the growth process, and the CeO2(110) layers growing in the areas without irradiation. The lateral orientation mapping by X-ray diffraction measurements reveal the existence of transition regions between these two orientation areas. The width of the transition region is found to　be considerably large and decrease proportionally as the logarithm of the underlying Si substrate resistivity. To make a breakthrough in the limitation in reduction of the transition region width, we propose a new method of OSE growth on silicon on insulator (SOI) substrates with lithographically formed trenches. The trenches prevent spread of the potential distribution to the neighboring Si islands. We report the experimental results showing perfect isolation between OSE grown regions having different crystallographic orientations, optimizing the Si layer thickness of SOI and the cross-sectional geometry of the trenches.

Figure 1
Reduced Graphene Oxide Hydrogel/Nickel Foam Electrodes, Fabricated By Electrophoretic Deposition for Supercapacitor Applications: Toward High Volumetric Capacitance
Authors: Dickerson James H. , Pham Viet Hung 
Published: February 2020

Supercapacitors, a class of electrochemical energy storage devices with superior power densities and long cycling lifetimes, have attracted great attention for the last decade due to their widespread application in backup power supply systems, portable devices, power tools, and hybrid electric vehicles. Graphene is considered as an ideal supercapacitor electrode material due to its large surface area, superior electrical conductivity, good chemical stability, and high mechanical strength. The theoretical specific capacitance of graphene is as high as ~ 550 F/g. The assembly of graphene sheets into three-dimensional interconnected porous microstructures, namely graphene hydrogels, has been considered the most effective approach to utilize these materials in supercapacitors that can achieve high specific capacitances. However, graphene hydrogels typically consist of large amount of water, up to 99 wt. %, resulting in very low graphene packing density. Therefore, the usual volumetric capacitance of graphene hydrogels is very poor, limiting their practical application.
In this study, we report a scalable method to prepare graphene hydrogels with high packing densities through the electrophoretic deposition of graphene oxide onto nickel foam, followed by an electrochemical reduction. The obtained, electrochemically reduced graphene oxide hydrogels (ERGO) on nickel foam were hydraulic compressed (up to 156 MPa) to increase the packing density of ERGO from 0.0098 to 1.32 g/cm3. In a two-electrode symmetric supercapacitor test using 6M KOH electrolyte, the compressed ERGO showed excellent performance with a volumetric specific capacitance up to 176.5 F/cm3 at a current density of 1 A g−1. Further, ERGO exhibited favorable cycling stability with retentions in range of 79 - 90 % after 10,000 cycles, depending on packing density of ERGO.
(Energy Technology Division Supramaniam Srinivasan Young Investigator Award) Na-M-S-O Quaternary Cathode Materials for High Voltage Sodium Batteries
Authors: Dwibedi Debasmita , Barpanda Prabeer 
Published: February 2020

Over the last decade, sodium-ion batteries are widely pursued as an alternative to Li-ion batteries. Similar to the Li-ion batteries, the development of sodium batteries rely on discovery and optimization of efficient insertion materials. In this pursuit, polyanionic materials are put on anvil to unravel novel compounds with descent electrochemical properties and thermal/ chemical stability. Guided by the inductive effect principle, the redox potential of polyanionic cathodes can be tuned by playing with the electronegativity of constituent anion units. Here, electronegative SO4-based materials can deliver the highest redox potential vis-a-vis other polyanionic materials. Based on this principle, novel Na2Fe2(SO4)3 alluaudite cathode has been recently reported offering ~100 mAh/g capacity along with high rate kinetics and cycling reversibility [Nature Communications, 5, 4358, 2014]. It marks the highest Fe3+/Fe2+ redox potential (ca. 3.8 V vs. Na/Na+). We have pursued this high-voltage Na-M-S-O quaternary insertion material system employing low temperature solvothermal synthesis like (i) ionothermal method, (ii) spray drying route and (iii) Pechini synthesis. We will describe these new synthetic routes to obtain alluaudite high-voltage cathode material for sodium-ion batteries. Using these green synthesis routes, we have explored other 3d metal homologues in Na-M-S-O quaternary system. Using experimental and DFT calculations, we will summarise the structure and electrochemical performance of Na-M-S-O quaternary alluaudite cathode materials.
Measuring Li+ Inventory Losses in LiCoO2/C Cells Using Ex-Situ Raman Spectroscopy
Authors: Snyder Chelsea Marie , Duquette David , Apblett Christopher A. , Grillet Anne M. , Beechem Thomas E. 
Published: February 2020

For the future progress of lithium ion batteries, identifying and understanding degradation mechanisms that affect the cycle-life are of major interest. Beyond identification, it is necessary to assess the relative influence of individual mechanisms to the totality of capacity fade [1-3
]. Specifically, comparisons between the relative impact of several mechanisms—primary active material loss (Li+ inventory), secondary active material loss (LiCoO2 and/or Graphite), and increased internal cell resistance (caused by surface films)—remain the topic of continued investigation [1]. Such effort is complicated by the dependence of these mechanisms to several parameters as it has been shown that their relative significance can vary based upon: the physical and chemical nature of the system, cycle rate [1], and testing temperature [2].
Owing to this complexity, multiple means of characterization are necessary to link global performance to the local mechanisms belying such performance. Most often electrochemical techniques are employed to link capacity fade to the aforementioned mechanisms [2-4]. Such techniques are unable, however, to specify local, crystal structure, alterations to this fade. In response, ex-situ Raman and electrochemical techniques are combined here to link local structural information of active particles to capacity loss. The Raman spectrum of LiCoO2 is sensitive to the state of lithiation and can therefore be leveraged to quantify the state of lithiation. Specifically, we investigate the Raman response of LiCoO2 cathode particles in full cells subject up to 80 cycles at slow rates (C/10), see Fig. 1. Cycle dependent changes in Raman spectra are compared to bulk electrochemical behavior – and hence capacity loss- demonstrating that such loss is linked to reductions in Li+ inventory commensurate with SEI formation and growth.

Acknowledgment

Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

References

G. Ning, B. Haran, and B. N. Popov, Journal of Power Sources, 117 (1-2), p. 160-169, 2003

M. Safari, and C. Delacourt, Journal of The Electrochemical Society, 158 (10), p. A1123-A1135, 2011

B. Stiaszny, J. C. Ziegler, E. E. Krauss, M. Zhang, J. P. Schmidt, and E. Ivers-Tiffée, Journal of Power Sources, 258, p. 61-75, 2014

J. Cannarella, and C. Arnold, Journal of Power Sources, 245, p. 745-751, 2014

Figure 1
Investigation of the Solid Electrolyte Interphase (SEI) in Polysulfide-Containing Glyme-Based Electrolytes
Authors: Agostini Marco , Shizhao Xiong , Matic Aleksandar , Hassoun Jusef 
Published: February 2020

The massive employment of non-renewable fossil fuels has resulted in a rapid increase of greenhouse gas emission and global warming. The consequent excessive climate changes have triggered a new energy policy, mainly focused on clean and renewable sources.
1
Solar and wind energy conversion systems are the most suitable for large-scale diffusion, in particular in view of recent advances reflecting in cost reduction and economic advantages.
1
However, these discontinuous energy sources require side systems for energy storage and electrical grid stabilization.
2
Furthermore, electrified vehicles using high-energy storage systems matching the automotive market requirements may effectively mitigate the environmental pollution in large urban areas.
2
Thus, there is a large push for the development of high capacity energy storage technologies.
Lithium−sulfur battery appears as one of the most promising technologies due to its high theoretical capacity and energy density, i.e. 1672 mAh g−1 and 3500 Wh kg−1 basing on the sulfur weight, respectively, the natural abundance, the low toxicity of elemental sulfur, and the expected low cost.
3
However, a sulfur electrode in a lithium battery shows several drawbacks, including poor electronic conductivity, high solubility of the polysulfides formed during the electrochemical process, large volume changes (approximately 80%) by operation, and precipitation of insoluble Li−S intermediates formed during the discharge process in the electrolyte solution. These remarkable issues, leading to severe capacity fading and Li−S cell deterioration upon cycling, have been already investigated in terms of the reaction mechanism.
4

Herein, we reported a detailed study of an important aspect, i.e., the chemical−physical and electrochemical characterization of the electrode−electrolyte interphase. Indeed, we comparatively investigate the properties of the SEI film formed at the lithium electrode surface in tetraethylene glycol dimethyl ether (TEGDME)-based electrolytes containing different polysulfide species, namely Li2S2, Li2S4, Li2S6, and Li2S8, added within a constant concentration of 5% w/w.
5

References

(1) Armand, M.; Tarascon, J.-M. Nature
2008, 451, 652−657.
(2) Bruce, P. G.; Freunberger, S. A.; Hardwick, L. J.; Tarascon, J.-M. Nat. Mater.
2012, 11, 19−29.
(3) Ji, X.; Nazar, L. F. J. Mater. Chem.
2010, 20, 9821−9826.
(4) Ryu, H.-S.; Guo, Z.; Ahn, H.-J.; Cho, G.-B.; Liu, H. J. Power Sources
2009, 189, 1179−1183.
(5) Agostini, M.; Shizhao, X.; Matic, A.; Hassoun, J. Chem. Mater
2015, 27, 4604−4611.
Development and Novel Characterization of All-Solid-State Thin Film Batteries
Authors: Wynn Thomas Andrew , Wang Ziying , Lee Jungwoo Zema , Rustomji Cyrus Sam , Meng Ying Shirley 
Published: February 2020

All-solid-state batteries are looked to for their high energy density and reduced capacity fade, and are a safer alternative to the conventional liquid electrolyte batteries currently being manufactured. However, few solid electrolytes are currently known. Amorphous lithium phosphorus oxynitride (LiPON) is a well-established solid electrolyte and is currently the only viable solid-state electrolyte for thin film batteries. LiPON is stable in contact with Li metal, but exhibits a relatively low ionic conductivity (10-6 S/cm2) [1]. A variety of other solid electrolytes with higher ionic conductivities are currently being explored, such as lithium lanthanum titanate (LLTO), achieving high lattice ionic conductivity of >10-3 S/cm2 [2]. We aim to enable LLTO as an electrolyte for thin film batteries via pulsed laser deposition. Additionally, performance of all-solid-state batteries is largely influenced by interfacial impedance and phase evolution during charge and discharge. The thin film geometry provides an ideal platform for analyzing the various electrode/electrolyte interfaces. Using novel focused ion beam and dynamic in situ transmission electron microscopy techniques, we have fabricated electrochemically active nanobatteries and observed their cycling behavior in situ. These techniques have been demonstrated on the layered lithium cobalt oxide (LCO)/LiPON interface, elucidating the mechanism of interfacial impedance which was previously unknown via ex-situ cycling experiments [3].
[1] N.J. Dudney, “Solid-state thin film rechargeable batteries,” Materials Science and Engineering: B, 116 (2005) 245-249.
[2] O. Bohnke, “The fast lithium-ion conducting oxides Li3xLa2/3 − xTiO3 from fundamentals to application,” Solid State Ionics, 179 (2008) 9-15.
[3] Z. Wang, D. Santhanagopalan, W. Zhang, F. Wang, H. Xin, K. He, J. Li, N. Dudney and Y.S. Meng, “In situ STEM/EELS Observation of Nanoscale Interfacial Phenomena in All-Solid-State Batteries,” Submitted.
The Role of the F Anion in the Spinel Structure for the Enhancement of High Rate Capability and Cyclability in LiNi0.5 Mn1.5 O4-XFx Crystals
Authors: Kim Dae-wook , Shiiba Hiromasa , Zettsu Nobuyuki , Teshima Katsuya 
Published: February 2020

Lithium ion secondary batteries are one of the most important energy storage systems because of their higher energy density and power density. In particular, many different types of cathode materials are studied for increasing capacity and cell potential. Spinel-type LiNi0.5Mn1.5O4 (LNMO) have been attracting significant attention due to higher redox potential, lower cost and low environmental load. The LNMO is possibly sorted into two type of spinel structure with different space group, ordered and disordered phase, which is typically identified due to formation of oxygen deficient, which cause reduction of Mn4+ to Mn3+ based on charge valance.
Disordered spinel structures could also lead to improved rate capability due to higher electronic conductivity and Li-ion diffusive of Mn3+ ion, However, too much concentration of Mn3+ lead to structural distortion and disproportionation, and which can be reduce cyclability. Thus, Mn cation adjustment is one of important factor for advanced LNMO electrode.
Therefore, in order to control efficiently Mn cation, fluorine was considered for substitution within LNMO. Because fluorine can easily control cation distribution due to charge valance and, which can adjust the degree of disorder. Besides, strong M-F bonding can be maintains spinel structure during long-term operation. In present work, we have demonstrated the flux growth of idiomorphic LiNi0.5 Mn1.5O4-xFx crystals and the effect of fluorine substitution on their LIBs characteristics, including rate capability and cyclability.
On Lithium Transference Number in Liquid-Solid Electrolytes
Authors: Popovic Jelena , Maier Joachim 
Published: February 2020

The application of high lithium transference number electrolytes in lithium ion batteries is greatly beneficial as they would prevent the occurrence of salt concentration gradients which may limit battery cell lifetime and energy density. In “soggy sand” electrolytes (insulating oxide nanoparticles dispersed in typically organic lithium salt solution), lithium transference number close to unity is expected to be achievable at high volume fractions as a consequence of disappearing bulk conductivity.[1] Such a trend has already been observed in the 1 M LiTf/PEGDME-150 containing mesoporous MSU-H nanoparticles.[2] A convenient way of circumventing particle network reproducibility and stationarity is by infiltration of monolithic hierarchically porous SiO2 (with various surface modifications) or Al2O3 with 1 M LiTf/PEGDME-150 leading to liquid-solid electrolytes with very high lithium transference number (0.75 to 0.89) without compromising high room temperature ionic conductivity (0.32 to 0.48 mS cm-1).[3] Additionally, importance of indirect (vehicular) transport mechanism of lithium and deconvolution of contributions of free ions and ion pairs to the overall conduction in LiTf/PEGDME-150 liquid electrolyte by a combination of experimental techniques (impedance spectroscopy, dc polarization, pulse field gradient NMR) will be discussed.[4] The pertinence of liquid/solid electrolytes is remarkable as they could make lithium battery separators dispensable offering form stability and excellent contact with high power nanostructured electrodes.

C. Pffafenhuber, M. Göbel, J. Popovic, J. Maier,
Physical Chemistry Chemical Physics, 15(42), 18318–18335, 2013.

C. Pfaffenhuber, F. Hoffmann, M. Fröba, J. Popovic, J. Maier, Journal of Materials Chemistry A, 1(40), 12560–12567, 2013.

J. Popovic, G. Hasegawa, I. Moudrakovski, J. Maier, Advanced Materials, submitted

J. Popovic, C. Pfaffenhuber, J. Melchior, J. Maier, Electrochemistry Communications, 60, 195–198, 2015.
Bacteria-Assisted Synthesis of Electrode Materials for Li or Na Batteries
Authors: Mirvaux Boris , Recham Nadir , Miot Jennyfer , Courty Matthieu , Guyot François , Larcher Dominique , Tarascon Jean Marie 
Published: February 2020

The production of materials for high-energy Li-ion batteries is generally associated with negative environmental footprints, due to high temperatures required and chemical toxicity of their components [1]. Our goal is to explore new bio-assisted low-temperature routes of synthesis in order to reduce this environmental impact and possibly improve their electrochemical performances.
Bacteria are easy to grow; able to mineralize transition metals and other elements [2], with controlled morphology, crystal structure and texture; they also constitute a potential source of conductive carbon. For these reasons, bacteria assisted synthesis caught our attention, especially as exceptional power performances were already shown for biomineralized hollow shells of hematite (α-Fe2O3) [3] when compared to those of non-textured material.
Hydrated amorphous ferric phosphate (a-FeIIIPO4·~3H2O) was precipitated from aqueous solution at 30°C under air at the contact of bacteria (Sporosarcina pasteurii). The resulting materials were investigated using various techniques (e.g. thermal analysis, mass spectrometry, infrared spectroscopy, electron microscopy) and consist of dead bacteria (2-3 µm x 0.5 µm) coated by a 70 nm thick layer of interconnected a-FeIIIPO4·~3H2O particles (40-80 nm), as presented by the following microscopy image. Surface chemistry of the bacterial cell wall plays a key role in the nucleation process thereby controlling particle size. After a mild temperature treatment, a 90 mAh/g capacity has been achieved versus Li (at 3.0 Volts mean voltage) with an excellent cyclability, constant coulombic efficiency (~100%) and interesting power performances. This approach allows overcoming the intrinsic poor conductivity of Fe phosphate without any use of harsh mixing treatments with conductive additive, or complex synthetic procedure.
Bacteria are capable of many things and we are now applying this strategy for other materials and other metals like manganese. We will also address the positive attributes of these bio-assisted synthesis for application in Na-based batteries.
[1] Samaras C., Meisterling K., Environmental Science & Technology. 42, 3170 (2008).
[2] Dupraz S. et al., Chemical Geology. 265, 54 (2009).
[3] Miot J. et al., Energy & Environmental Science. 7, 451 (2014).

Figure 1