bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solution Processed Alternating Organic/Inorganic Multilayer for OLED Encapsulation
Authors: Sun Lina , Kurosawa Yuu , Yoshida Tsukasa , Suzuri Yoshiyuki 
Published: February 2020

Organic light-emitting diodes (OLEDs) are promised to replace the existing displays and lightings in terms of the quality of light. One of the most exciting features of organic electronics is that they can be made flexible. However, flexible OLED encapsulation is actually one of the major challenges because they are very sensitive to oxygen and moisture. Thin-film encapsulation (TFE) prepared by vacuum-deposition processes (ALD, CVD) have high barrier properties, but low throughput and high cost. For the significant cost reduction, all solution-processed roll to roll (R2R) production of OLEDs need to be established. Among the technologies needed, that for the thin-film encapsulation (TFE) imposes the highest challenge, because thin films with a very high level of barrier performance needs to be fabricated onto a complete organic device, so that solvents to attack the materials and high temperature treatments need to be strictly avoided.
In this work, organic/inorganic multilayer encapsulation structures based on one step solution-processed alternating polysiloxane and silica layer are presented in Fig. 1(A), in which organic layers are spin-coated, followed by polymer crosslinking reaction, and finally subjected to photochemical conversion of the surface into dense silica barrier layers under exposure to vacuum ultraviolet（VUV) light. The whole process is very simple and fast to perform at room temperature, and the coating solution is successfully developed not to destroy the pre-formed organic emitting layer.
Transmission electron microscopic (TEM) image shows successful fabrication of multi-stacks of organic/SiOx hybrid alternating layers (Fig. 1(B)). The thickness of ~ 100 nm was achieved per coating. The performance of such multilayer as thin-film encapsulation (TFE) of an OLED device has also been investigated as shown in Fig. 1 (C). The preliminary life time to reach 90% of the initial luminance (5000 cd/m2) was 73 hours for the OLED encapsulated with 450 nm TFE, about 6 times extended compared to that of the bare device.

Figure 1
(Invited) Control of Silicon Doping Level By Self Limited Reactions
Authors: Laus Michele , Perego Michele 
Published: February 2020

Precise control over dopant dose and distribution at the nanoscale is required to support further evolution in microelectronics, photovoltaics, solar fuel conversion, sensors, and quantum computation.
In this contribution, an effective bottom-up technology is proposed as a promising solution to overcome the limitations of conventional doping approaches.
Precise control of the amount of dopant atoms tethered on silicon substrates is presented, based on polystyrene and poly(methyl methacrylate) polymers, with controlled molar mass and featuring a narrow molar mass distribution, end-terminated with a P-containing moiety. These polymers are spin coated and subsequently end-grafted onto nondeglazed silicon substrates. P atoms were bonded to the surface during the grafting reaction, and their surface density is set by the polymer molar mass, according to the self-limiting nature of the “ grafting to” reaction. Polymeric material was removed by O2 plasma hashing without affecting the tethered P-containing moieties on the surface.
Repeated cycles of polymer grafting followed by plasma hashing led to a cumulative increase, at constant steps, in the dose of atoms grafted to the silicon surface. P injection in the silicon substrate was promoted and precisely controlled by high temperature thermal treatments. Sheet resistance measurements demonstrated effective doping of silicon substrate.
Although the method is demonstrated for P-containing molecules on planar deglazed and nondeglazed Si substrates, but the it can be readily implemented to other types of dopants and semiconductor substrates by using suitable combination of dopant-containing moieties and surface chemistry.
Orientational Distribution of Reinforcing Fibers of Thermoplastic Composites Produced By Compression Molding – Heat & Cool vs Cold Pressing
Authors: Yamamoto Tetsuya , Masubuchi Yuichi 
Published: February 2020

We theoretically predict the orientational dynamics of the reinforcing fibers of thermoplastic composites during the compression molding for cases in which the composites are molded by using the heat & cool (H&C) technique and by using the cold pressing technique [1]. For simplicity, we treat cases in which a cylindrical material, in which fibers are randomly oriented in a melt thermoplastic, is compressed by parallel plates. The compression is stopped when the material becomes the prescribed thickness for cases in which the H&C is used and it is stopped when the entire region of the material is solidified for cases in which the cold pressing is used. We derive the local orientational order parameter, which characterizes the extent of the orientational ordering of the fibers towards the flowing direction, after the molding process as a function of position [2].
Our theory predicts that the orientational order parameter is determined by the total shear strain applied to the fibers during the molding process. For cases in which the composite is molded by H&C, the orientational order parameter decreases as a function of the distance from the molds because the shear rate decreases with separating from the molds. The orientational order parameter does not depend on the compression speed because the orientations depend on the total shear strain applied to the fibers. In contrast, for cases in which the composite is molded by cold pressing, the orientational order parameter is a non-monotonic function of the distance from the molds, with a maximum at a half-way between the mold and the middle plane. This is because the reorientation of the fibers stops when the background thermoplastic material is solidified and the shear rate decreases with separating from the solidification front. The orientational order parameter depends on the compression speed and the speed of solidification. We thus conclude that the orientational distribution of the reinforcing fibers of thermoplastic composites is sensitive to the solidification dynamics of the background thermoplastic material.
[1] T. Ishikawa et al., Compos. Sci. and Technol., 155, 221 (2018).
[2] M. Doi and S. F. Edwards, The Theory of Polymer Dynamics, Oxford Univ. Press, 1986
(Invited) On the NaMeO2 (Me = 3d metal) for Na-Ion Batteries
Authors: Komaba Shinichi , Kubota Kei 
Published: February 2020

Since the first report of NaMeO2 electrode about 40 years ago, the oxides have attracted much attention in battery researchers’ community particularly after 2010 because of their new chemistries different from LiMeO2 as well as abundant material-resources in the Earth [1-4]. Table 1 shows the variety of directly crystalizable oxides of A
x
MeO2s (A = Li, Na, and K) on 3d transition metal species. Clearly, Na
x
MeO2 crystalizes with a wider variety of 3d transition metals without Na/Me cation-mixing unlike Li/Me due to proper difference in ionic radii between Na+ and Me3+ ions [5-7]. The wide variety of 3d metals and crystal structures such as O3, P3, and P2 types including the distorted ones are found only in the Na system [5-7], unlike Li and K cases. Such structural variety gives us so wide selection of Na
x
MeO2 materials, which is highly attractive to develop high-performance positive electrode and to fine new electrochemical properties. Even if the same 3d transition metal is adopted in Li and Na systems, the electrochemical properties are often different from Na one in the batteries. For examples, O3-type LiCrO2 is electrochemically inactive in a Li cell, while O3-NaCrO2 delivers a reversible capacity of ca. 120 mAh g-1 with anomalously high thermal-stability in Na cell [8,9], which is also found in between O3-LiFeO2 and O3-NaFeO2 [10-12]. Our group has studied layered Na
x
MeO2 since 2005, and our achievements and recent progress on the layered oxides will be presented.

Reference
s
:

[1] N. Yabuuchi, K. Kubota, M. Dahbi and S. Komaba, Chem.
Rev., 114, 11636 (2014).
[2] M. Dahbi, K. Kubota, S. Komaba et al., Phys.
Chem. Chem. Phys., 16, 15007 (2014).
[3] K. Kubota and S. Komaba, J. Electrochem. Soc., 162, A2538 (2015).
[4] K. Kubota, S. Komaba et al., Chem. Rec., 18, 459 (2018).
[5] C. Delmas, C. Fouassier, and P. Hagenmuller, Mater. Res. Bull., 11, 1483 (1976).
[6] K. Kubota, S. Komaba et al., MRS Bull., 39, 416 (2014).
[7] K. Kubota, S. Komaba et al., Adv. Energy Mater., 8, 1703415 (2018).
[8] S. Komaba et al., Electrochem. Commun., 12, 355 (2010), and J. Phys. Chem. C,
119, 166–175 (2015).
[9] N. Yabuuchi, S. Komaba, et al., ACS Appl. Mater. Interfaces,
8, 32292−32299 (2016).
[10] K. Ado, et al., J. Electrochem.
Soc., 144, L177 (1997).
[11] S. Okada, the 210th ECS Meet., Cancun, Mexico (2006).
[12] N. Yabuuchi, S. Komaba et al., Electrochemistry, 80, 716 (2012).

Figure 1
(Invited) Hybridizing Fullerenes and Two-Dimensional Nanomaterials
Authors: Yang Shangfeng 
Published: February 2020

Fullerene has a definite zero-dimensional (0D) closed-cage molecular structure composed of sp2-hybridized carbon atoms merely, enabling it as important building blocks useful for constructing supramolecular assemblies and micro/nano functional materials.[1] Upon hybridization 2D nanomaterials with fullerenes noncovalently or covalently, the physical/chemical properties of 2D nanomaterials can be tailored and in most cases improved, significantly extending their functionalities and applications.[2] Recently, we succeeded in synthesizing several novel fullerene-2D nanomaterial hybrids via both covalent and noncovalently approaches, including graphene,[3] g-C3N4,[4] black phosphorus,[5] and MoS2,[6] and achieved enhanced photo/electrocatalytic activities.
References:

S. F. Yang, T. Wei, F. Jin, Chem. Soc. Rev.
2017, 46, 5005-5058.

M. Q. Chen, R. N. Guan, S. F. Yang, Adv. Sci.
2018, 10, DOI: 10.1002/advs.201800941.

J. Guan, X. Chen, T. Wei, F. P. Liu, S. Wang, Q. Yang, Y. L. Lu, S. F. Yang, J. Mater. Chem. A
2015, 3, 4139.

X. Chen, H. L. Chen, J. Guan, J. M. Zhen, Z. J. Sun, P. W. Du, Y. L. Lu, S. F. Yang. Nanoscale
2017, 9, 5615.

X. J. Zhu, T. Zhang, D. Jiang, H. Duan, Z. Sun, M. Zhang, H. Jin, R. Guan, Y. Liu, M. Chen, H. Ji, P. Du, W. Yan, S. Wei, Y. L. Lu, S. F. Yang,
Nature Commun.
2018, 9, 4177.

J. Guan, J. H. Wu, D. C. Jiang, X. J. Zhu, R. N. Guan, X. Y. Lei, P. W. Du, H. L. Zeng, S. F. Yang, Int. J. Hydrogen Energy
2018, 43, 8698.
(Invited) Cobalt Interconnects at 36nm Beol Pitch and Beyond: Material Challenges & Circuit-Level Performance Impact
Authors: Lanzillo Nicholas , Yogendra Karthik , Yang Chih-Chao , Vega Reinaldo , Bolam Ron , Choi Kisik , Robison Russ , Clevenger Larry 
Published: February 2020

Cobalt metallization in the back-end-of-line (BEOL) presents several interesting opportunities and challenges1-5. In this work, we evaluate the performance of Co interconnects at narrow BEOL pitch using chemical vapor deposition (CVD) for Co and a Ta-based barrier layer. In-line electrical measurements demonstrate a higher RC-delay for Co interconnects relative to Cu interconnects. Various challenges associated with Co metallization at narrow-pitch are identified. Simulations based on temperature-coefficient of resistivity (TCR) measurements are used to identify various cross-over points in which Co line resistance becomes lower than Cu line resistance depending on width, aspect ratio and barrier material/thickness.
In addition to in-line characterization of damascene Co interconnects, we employ a state-of-the-art multi-scale modeling approach to evaluate overall BEOL-loaded device performance for both Co and Cu conductors. We consider a single-driver reference circuit6,7 to evaluate the delay penalty for Co v. Cu metallization at several representative pitches. Ab initio simulations are employed to determine lower-limits of Co via resistance and surface scattering for a variety of possible barrier materials and thicknesses. These results are fed into a field solver to calculate stage delay for several representative logic gates, including a 3-input NAND and a 2-input multiplexer (MUX). Results indicate that despite having a higher line resistance, a net improvement in stage delay can be achieved for a suitably-tuned Co via resistance. Critical dimension (CD) sensitivity is also characterized for both Co and Cu metallization schemes.
These results highlight some of the challenges and potential advantages of using Co-based conductors in advanced interconnects beyond the 7nm technology node. This work was performed by the Research and Development Alliance Teams at various IBM Research and Development Facilities.

Figure 1
Nanoengineered Separators for a High Energy Density, Long Cycle Life Li-S Battery
Authors: Xing Weibing 
Published: February 2020

Rechargeable lithium-sulfur (Li-S) batteries are widely considered the most promising “Beyond Li-ion” candidates, notably for their high theoretical energy density. The low and moderate atomic weight of Li and S, respectively, translates to a battery chemistry pairing that is lightweight. Since each S atom can ultimately host two lithium ions (Li+), compared with 0.5–0.7 Li+ per host atom in Li-ion batteries [1], the Li-S battery chemistry offers a much higher Li storage capacity potential. Assuming a complete redox couple reaction, S8 + 16Li+ + 16e- ↔ 8Li2S, the S cathode can have a high theoretical specific capacity of 1672 mAh/g with an average discharge voltage of ~2.1V (vs. Li/Li+), which leads to a theoretical specific energy of ~2500 Wh/kg based on the active material weight of a Li-S cell [2]. Other compelling attributes of Li-S batteries include high S natural abundance, low cost of S materials and safety characteristics owing to an intrinsic tolerance to overcharge [3]. In addition, the primary constituents of Li-S batteries are non-toxic and environmentally friendly [4].
However, currently no commercial Li-S battery exists due to some significant technical challenges that have thus far prevented the realization of the tremendous energy density and performance potentials of Li-S batteries. These technical challenges include: low practical specific energy or energy density yield, significant capacity loss with cycling, high self-discharge rates, low Coulombic efficiency and safety concerns due to the use of Li metal anode [5].
We will present our efforts in the development of a high energy density and long cycle life Li-S battery technology via nanoengineered battery separators. We will show that our atomic and/or molecular level, functional material coated separators exhibit much improved physical properties including tensile strength, thermal shrinkage, and electrolyte wettability (Figure 1). When used in Li-S cells, the nanoengineered separators (coated) afforded a significant increase in specific capacity compared with the control (uncoated) separator, as illustrated in Figure 2. The enhanced Li-S cell performance suggests polysulfide blockage from the nanoscale functional material coated separators used in the resultant Li-S cells.
Our study demonstrates that the nanoengineered separator approach represents a very promising strategy to develop a high energy density, long cycle life, safe and economically scalable Li-S battery technology.

References

Bullis, “Revisiting Lithium-Sulfur Batteries” MIT Review, May 22, 2009.

Arumugam Manthiram, Yongzhu Fu, and Yu-Sheng Su, Acc. Chem. Res., 46 (5), pp 1125–1134 (2013)

James R. Akridge, “Lithium Sulfur Rechargeable Battery Safety”, Battery Power Products & Technology, October 2001.

Yongguang Zhang, Yan Zhao, Kyung Eun Sun and P. Chen, The Open Materials Science Journal, 5, 215-221 (2011).

Monica Marinescu, Laura O’Neill, Teng Zhang, Sylwia Walus, Timothy E. Wilson, and Gregory J. Offer, J. Electrochem. Soc, 165 (1) A6107-A6118 (2018).

Figure 1
Atomic Layer Deposition of Nanocomposite Fluoride Coatings for Li-Ion Batteries
Authors: Mane Anil U. , Choudhury Devika , Gutierrez Arturo , Croy Jason R. , Elam Jeffrey W. 
Published: February 2020

The energy storage market is projected to reach >$50 billion in the next five years. Major segments of this market consist of rechargeable lithium-ion batteries for consumer electronics, electric vehicles (automobiles, drones, aviation and space applications) and stationary storage for smart grids. For all these applications, high energies and capacities are required to meet the needs of consumer demands and economic viability. However, in order to meet these demands, lithium-ion materials must operate successfully at relatively high voltages (i.e. ≥ ~4.4V vs. Li/Li+) in practical cells. In particular, the cathode/electrolyte interfaces must be stabilized to prevent deleterious electrochemical reactions which can cause transition metal dissolution, capacity fade, and cell failure.
The conventional approach to stabilize cathode surfaces is to use protective coatings consisting mostly of metal oxides such as TiO2, ZrO2, HfO2, and Al2O3. However, despite nearly two decades of research and development, these metal oxide coatings are still susceptible to chemical attack by hydrogen fluoride (HF) that forms in the liquid electrolyte during battery cycling. The HF dissolves the metal oxide coatings exposing the underlying cathode material. To resolve the issues related to HF and improve electrode-surface stability, we have developed atomic layer deposition (ALD) based, nanocomposite fluoride coatings that resist dissolution by HF. We have added ultrathin nanocomposite fluoride coatings on various cathode materials such as conventional LiCoO2, various NMCs-(e.g., LiMO2, M=Mn, Ni, Co), and Li/Mn-rich, layered-layered-spinel (LLS) composite cathodes. These coatings are found to significantly improve the stability and performance of the cathodes in lithium-ion cells. Here we will present ALD growth of nanocomposite fluorides for Li-ion batteries and some of the latest electrochemical results.
(Invited) Model-Based Battery Management System of Lithium-Ion Batteries
Authors: Pathak Manan , Kolluri Suryanarayana , Jang Taejin , Pathak Chintan , Santhanagopalan Shriram , Subramanian Venkat R. 
Published: February 2020

The advances in the automotive sector for plug-in hybrid electric vehicles (PHEV) and battery electric vehicles (BEV) along with penetration of renewables for power generation, cell phones and electric-flights have increased the use of batteries, as energy storage devices to a great deal. Some limitations of existing lithium-ion battery technology include underutilization, stress-induced material damage, capacity fade, and the potential for thermal runaway.1-3

Model-based control approaches (Model predictive control) can be used to design a smarter Battery Management System (BMS) that guarantees safety, efficiency, lifetime and performance of lithium-ion batteries at the stack and module level.4-7 This talk will present approaches for determining model-based optimal charging profiles for batteries, and experimental validation of the same. Optimal profiles that increase the cycle life of the cells were implemented on 16 Ah cells. An improvement of more than 100% in cycle life is observed experimentally, for our test conditions on this cell design.8 To test across multiple chemistries and form factors, optimal profiles were also implemented on a 1.5 Ah cylindrical cell, leading to an improved cycle life for these cells.
The interplay between the fundamental depth in modeling, choice of numerical algorithms, and application-driven problem formulation will be presented.

Acknowledgements

The work presented herein was funded in part by the Advanced Research Projects Agency – Energy (ARPA-E), U.S. Department of Energy, under Award Number DE-AR0000275 along with the Clean Energy Institute (CEI) at the University of Washington (UW) and the Washington Research Foundation.

References

P. Arora, R.E. White, and M. Doyle, Journal of the Electrochemical Society, 145, 3647 (1998).

V. Ramadesigan, P.W.C. Northrop, S. De, S. Santhanagopalan, R.D. Braatz, and V.R. Subramanian, Journal of the Electrochemical Society, 159, R31 (2012).

S. Santhanagopalan, Q. Guo, P. Ramadass and R.E. White, Journal of Power Sources, 156, 620 (2006).

B. Suthar, P.W.C. Northrop, R.D. Braatz,and V.R. Subramanian Journal of the Electrochemical Society, 161, F3144 (2014).

B. Suthar, V. Ramadesigan, P.W.C. Northrop, B. Gopaluni, S. Santhanagopalan, R.D. Braatz, and V.R. Subramanian, in American Control Conference (ACC), p. 5350, Seattle, WA, USA (2013).

M. Torchio, L. Magni, R.D. Braatz, and D.M. Raimondo, in 11th IFAC Symposium on Dynamics and Control of Process Systems, including Biosystems, p. 827, Trondheim, Norway (2016).

M. Torchio, N.A. Wolff, D.M. Raimondo, L. Magni, U. Krewer, R.B. Gopaluni, J.A. Paulson, and R.D. Braatz, in American Control Conference (ACC), p. 4536, Chicago, IL, USA (2015).

M. Pathak, D. Sonawane, M. Powell, S. Santhanagopalan, R.D. Braatz, and V.R. Subramanian, ECS Transactions, 75, 51 (2017).
Water Oxidation and Surface Protonation of Small IrOx Clusters
Authors: Juhasz Gergely 
Published: February 2020

Electrochemical water oxidation on the anode is a common bottleneck of electrocatalytic processes. For their efficiency and relative stability, IrOx-type anodes are among the best ones in acidic environment. In spite of all the efforts, however, it is still a complicated system from theoretical point of view. The small band gap and complicated band structure around Fermi level, strong electron correlation makes Ir(IV) oxides challenging itself, and the amorphous structure or nanoparticle structure of the electrodes just adds to the complications.
We focused on these later aspects and studied the behavior of small cluster models of IrOx (Ir3 and up), instead of regular slab models. Crystalline IrO2 has a rutile lattice where Ir atoms are forming Ir-O-Ir chains along the x/y and Ir-O2-Ir chains z direction. In amorphous oxides and nanoclusters those chains are terminated by –OH or –OH2 groups, to compensate the missing positive charges. In our cluster models we mostly kept the local environment around most Ir similar to bulk, but studied the effect of terminating –OH and –OH2 groups, i.e. the H isomerism on the cluster surface.
For the calculation we used DFT (DMol3) with the PBE (GGG) functional and DNP (4.4) basis set. The convergence criteria of for geometry optimization was 1.0-5 Ha and 1.0-6 for the SCF. Due to the large number of states around the HOMO-LUMO gap, we applied thermal smearing. The accuracy of the calculations was assessed compared to calculations with B3LYP hybrid functional, however the geometry and charges remained essentially the same. We found that surface protonation can significantly stabilize the lower valence states of Ir, therefore mobile H on the surface can reduce the energy required for each step of the water oxidation cycle.