bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nano-Crystalline Oxide Semiconductor Materials for Display and Semiconductor Device Applications
Authors: Jeon Sanghun 
Published: February 2020

Ever evolving advances in oxide semiconductor materials and devices continue to fuel leading edge developments in display technology, and transparent electronics, thanks to new integration processes, enabling large area processing on rigid and flexible substrates. Nanocrystalline oxide semiconductor offer a host of advantages such as low cost and high scalability, in addition to seamless heterogeneous integration with a host of other inorganic and organic materials in view of its low thermal budget in processing which provides integration flexibility. This has spawned a wealth of applications ranging from high frame rate interactive displays with embedded imaging to flexible electronics, where speed and transparency are essential requirements Therefore, transparent electronic systems, which have been once viewed as science fiction, can now become a reality. In semiconductor device applications, interest in oxide semiconductors stem from a number of attributes primarily their ease of processing, and high field effect mobility, resulting in stackable process nature on silicon circuits. In this talk, various semiconductor device applications via nanocrystalline oxide semiconductor materials will be presented.
In the first part of our presentation, as seen in Figure 1, we present a photo-transistor embedded in a display pixel, in which gate operation is used to accelerate recovery from photocurrent level to the dark state. We describe the origin of ultra-high quantum efficiencies in photo-sensors based on nanocrystalline oxide hetero-junction thin film transistor (TFT). In order to understand the origin of high photocurrent of a device, we evaluated the influence of a light spot from source to drain side on the photoconductive gain of photosensor array. This work here demonstrates high sensitivity image sensor along with quantitative analysis of the quantum efficiency in the hetero-junction TFT taking into account the optical absorption, electron lifetime, and transit time.
The integration of electronically active oxide components onto silicon circuits represents an innovative approach to improving the functionality of novel devices. Like most semiconductor devices, complementary-metal-oxide-semiconductor image sensors (CISs) (see Figure 2) and memory devices have physical limitations when progressively scaled down to extremely small dimensions. In the 2nd part of presentation, we propose a novel hybrid CIS architecture and memory architectures that are based on the combination of nanometer-scale oxide thin-film transistors (TFTs) and a conventional Si device. The results demonstrate how our stacked hybrid device could be the starting point for new device strategies in image sensor architectures. Furthermore, we expect the proposed approach to be applicable to a wide range of micro- and nanoelectronic devices and systems.
Electrodeposition and Evaluation of Ruthenium Film from Divalent Ruthenium Electrolyte
Authors: Chiba Shintarou , Fujinami Tomoyuki , Arai Susumu 
Published: February 2020

Introduction

Ruthenium is a platinum-group element with properties similar to those of rhodium, which also is a platinum-group element. Compared to rhodium, ruthenium is considerably cheaper and its industrial applications have gradually been increasing. Ruthenium plating films are expected to be used for electrical contact parts due to their low contact resistance, abrasion resistance, and corrosion resistance. However, very few studies on ruthenium plating have been reported thus far. As ruthenium has a small hydrogen overpotential, the generation of hydrogen gas during electrodeposition should occur easily. Therefore, electrodeposition of ruthenium from ionic liquids instead of aqueous solutions has been investigated.1,2) In addition, ruthenium plating baths containing trivalent ruthenium ions are often used for electrodeposition. We have examined the electrodeposition of ruthenium films from a bath containing divalent ruthenium ions.3)

In the present study, the electrodeposition behavior and microstructure of these films were studied.

Experimental

An electroplating bath containing 0.1 M RuCl3•nH2O and 0.5 M L (+)-ascorbic acid was prepared. Trivalent ruthenium ions were changed to divalent ions by the addition of ascorbic acid. Copper plates were used as substrates. Plating was performed at 80°C with aeration under galvanostatic conditions (current density; 5 A dm-2, electrical charge; 50 C cm-1). A phase structure analysis of the deposits was performed using X-ray diffraction (XRD). The surface morphology and cross-sectional texture were observed using field–emission scanning electron microscopy (FE-SEM). Elemental mapping was carried out using electron probe X-ray micro-analysis (EPMA). Wear testing was performed using a scratch tester. The surface hardness was measured using a micro-Vickers hardness tester.

Results and Discussion

Figure 1 shows an SEM image of the ruthenium plating film surface. Some cracks are seen on the surface of the film. Figure 2 shows a cross-sectional SEM image of the film, which has a thickness of about 2 µm. Although a crack is seen, there are no voids in the film. It was found that the film had a low degree of crystallinity and contained a certain amount of chlorine, by XRD analysis and EPMA analysis, respectively.
Properties of the ruthenium film will be discussed at the meeting.

References

1) O. Mann, W. Freyland, O. Raz, Y. Ein-Eli, Chem. Phys. Lett., 460, 178 (2008).
2) O. Raz, G. Cohn, W. Freyland, O. Mann, Y. Ein-Eli, Electrochim. Acta, 54, 6042 (2009).
3) Y. Miyagawa, S. Arai, M. Endo, Abstract of the Electrochemical Society Japan Fall Meeting 2006, p.271 (2006).
4) S. Chiba, S, Arai, T, Fujinami, Abstract of The Surface Finishing Society of Japan 128th Meeting, p.27 (2013).
A Theory of Li Percolation in Rocksalts and Demonstration as Capacity Cathode Materials with Substantial Cation Disorder
Authors: Ceder Gerbrand , Urban Alex , Li Xin , Lee Jinhyuk 
Published: February 2020

There is a clear need to develop dense, lithium intercalation oxides with > 200 mAh/g practical capacity. Today, nearly all high energy density cathodes for rechargeable lithium batteries are well-ordered materials where lithium and other cations occupy distinct sites. Cation-disordered materials are generally disregarded because lithium diffusion tends to be limited in them. The recently demonstrated performance of Li1.211Mo0.467Cr0.3O2, achieving close to 300 mAh/g, shows that lithium diffusion can be facile in disordered materials [1] and made us revisit the question of how Li diffuses through rocksalt-like materials. We have combined ab initio computations of local Li migration barriers with percolation modeling to develop a unified understanding of Li diffusion in close-packed oxides. The theory explains the high capacity of layered and spinel-like materials, and the lack of reversible capacity in γ-LiFeO2. More surprisingly, the new percolation theory also clearly supports that Li-excess is needed to achieve high capacity in partially or fully disordered materials. We can now give very specific guidelines for the amount of Li-excess needed in order to achieve a particular reversible capacity, and open up a new direction for finding very high capacity cathodes.
[1] J. Lee, A. Urban, X. Li, D. Su, G. Hautier, G. Ceder, Unlocking the Potential of Cation-Disordered Oxides for Rechargeable Lithium Batteries, Science, 343 (6170), 519-522 (2014)
Evaluating Si-Based Materials for Commercially Relevant Li-Ion Batteries
Authors: Chevrier Vincent L , Liu Li , Le Dinh Ba , Krause Larry J , Jensen Lowell , Figgemeier Egbert , Eberman Kevin W 
Published: February 2020

Methods and criteria for assessing the commercial viability of Si-based materials are discussed and demonstrated with the 3M V6 alloy and 60 nm nano Si powder. These materials are firstly evaluated through the cycling of neat electrodes containing only alloy and binder to characterize the capacity, first cycle efficiency, binder compatibility, and microstructure stability of the material. The alloy displays higher first cycle efficiency, lower fade, and a more stable amorphous microstructure compared to the nano Si, which displays a variable microstructure with a rate dependent presence of crystalline Li15Si4.
Figure 1 shows the dQ/dV of neat electrodes containing (a) only nano Si and LiPAA binder for which the Li15Si4 peak gradually decreases, and (b) Si-based alloy (V6Neat) and LiPAA binder with a dQ/dV characteristic of amorphous Si.
The materials are then evaluated in graphite-containing composite electrodes having high areal capacities (> 2 mAh/cm2). In a well designed composite electrode including carbon nanotubes, 3M V6 material was found to cycle with little fade and high coulombic efficiency (~99.8%) while maintaining a stable dQ/dV. A composite electrode of equivalent volumetric capacity with nano Si powder shows similar capacity retention over 50 cycles but an unacceptably low coulombic efficiency (~99.2%). High precision coulometry and calorimetry results show surface area as the dominant factor in levels of parasitic reactions with Si based materials.
A review of failure modes for various Si implementations and their impact on full cell cycling will also be presented.
Thermal and Structural Behavior of Surface-Modified Li[Ni0.7Co0.2Mn0.1]O2 As a Positive Electrode for Rechargeable Lithium Batteries
Authors: Jo Chang Heum , Myung Seung-Taek 
Published: February 2020

Lithium secondary battery is promising as a power backup for energy storage system. In this respect, studies towards improvement in performances of electrode are being progressed to assure long cycling performances, thermal stability, safety, and so on. In particular, positive electrode materials are need to be further investigated to accomplish the above- mentioned properties. Several kinds of 4 V class positive electrode materials are commercially available. Among them, LiCoO2 is one of the most common electrode materials in rechargeable lithium batteries. Although the LiCoO2 has many advantages, this material has poor capacity retention because of dissolution of Co and structural instability at deeply charged state. To improve the nature of active material, surface modification is effective to overcome those limited properties of active materials. Actually, Metal oxides as coating materials have been extensively studied. In this study, Metal phosphate coatings are applied on the surface of Li[Ni0.7Co0.2Mn0.1]O2. We, here, report the resulting structural, electrochemical and thermal properties of the surface-modified Li[Ni0.7Co0.2Mn0.1]O2.
H3PO4 and metal salts were selected as starting materials for surface modification of Li[Ni0.7Co0.2 Mn0.1]O2. A solution anhydrous ethanol containing metal phosphates was stirred at 30 oC for 5 hours. Then, active materials were added into the solution. And the solution was evaporized at 80 oC in air and the resulting precipitates were then heated at 500 oC in air. Also, the coated powders were characterized by XRD, SEM, and HR-TEM. Electrochemical properties of coated powders were examined by galvanostatic cycle test and electrochemical impedance spectroscopy.
Metal phosphates coatings shows uniform coating layers, as observed by TEM. TG and DSC analyses were conducted for the materials. Electrochemical test with half cells in voltage range of 3 - 4.3 V at 25 oC indicates that coated materials have better capacity retention and coulombic efficiency, rate capability and thermal properties. Thin coating layers were effective in improvement of the electrochemical, structural and thermal properties. Also, metal phosphates coatings give decrease in the residual lithium content and byproduct on the surfaces of particles, as confirmed by ToF-SIMS. And the materials were analyzed into XPS and ToF-SIMS to confirm surface byproducts of the materials itself at high temperature. Details will be mentioned at the conference site.
A High Rate Lithium-Rich Layered MNC Cathode with Low Capacity Fade for Li-Ion Batteries
Authors: Ates Mehmet Nurullah , Mukerjee Sanjeev , Abraham K.M. 
Published: February 2020

We report a new synthesis method, termed self-sustaining combustion reaction, that resulted in a lithium-rich MNC (LLMNC) cathode material with high rate capability and excellent capacity maintenance during cycling compared to the lithium-rich metal oxide cathode materials previously reported in the literature (
1-4
). This porous, sponge-like composite metal oxide of the composition, 0.5Li2MnO3. 0.5LiMn0.5Ni0.35Co0.15O2, was characterized by means of its X-ray diffraction (XRD) pattern, FESEM (Field Emission Scanning Electron Microscopy) images and electrochemical data. The interconnected pore structure of the material with enhanced surface properties (figure 1, inset) compared to its previously known counterpart synthesized from the co-precipitation method provides higher rate capability with low capacity fade during long-term cycling.
The XRD pattern of the material, with the Li2MnO3 region magnified, presented in Figure 1, perfectly matches with the literature data(
3
) for the layered Li-rich MNC material of similar composition. We obtained discharge capacities of approximately 300, 250, 200 and 150 mAh/g at C/20, C/4, and C and 2C discharge rates for electrodes having an active material loading of approximately 7 mg/cm2. Remarkably, excellent capacities with practically zero capacity fade has been observed for hundreds of cycles at the C discharge rate as shown in Figure 2 for a Li half-cell cycling between 2-4.9V at room temperature. Detailed structural and electrochemical properties of the material characterized using cyclic voltammetry (CV), XRD, X-ray Absorption Spectrometry (XAS), FESEM and High Resolution Transmission Electron Microscopy (HRTEM) will be discussed.
References:
1. M. N. Ates, Q. Jia, A. Shah, A. Busnaina, S. Mukerjee and K. M. Abraham, Journal of The Electrochemical Society, 161, A290 (2014).
2. Y. Chen, G. Xu, J. Li, Y. Zhang, Z. Chen and F. Kang, Electrochimica Acta, 87, 686 (2013).
3. A. Ito, D. Li, Y. Ohsawa and Y. Sato, Journal of Power Sources, 183, 344 (2008).
4. F. Amalraj, D. Kovacheva, M. Talianker, L. Zeiri, J. Grinblat, N. Leifer, G. Goobes, B. Markovsky and D. Aurbach, Journal of The Electrochemical Society, 157, A1121 (2010).
Polycarbonate-Based Solid Polymer Electrolytes for Li-Ion Batteries
Authors: Sun Bing , Mindemark Jonas , Edström Kristina , Brandell Daniel 
Published: February 2020

Conventional Li-ion batteries containing flammable and volatile liquid electrolytes are challenged to deliver safe and stable performance for practical energy storage applications. Alternatively, solid polymer electrolytes (SPEs), which intrinsically eliminate the use of organic solvents, display good mechanical stability and flexibility against physical deformation of battery pack and volume retention of electrode materials. The use of SPEs with high thermal and electrochemical stability would contribute to the design and manufacture of safe and cost-effective Li-ion batteries, especially for large-scale applications under elevated temperatures [1].
Host materials for most SPEs have yet been dominated by polyethers with ethylene oxide (EO) and propylene oxide (PO) as repeating units. As an interesting replacement to the low-molecular-weight cyclic and linear carbonates, a new class of polymer hosts based on polycarbonates has been considered as Li+-conducting electrolytes [2]. The incorporation of polar carbonate units in the polymer host could effectively facilitate the separation of ion clusters and allow high salt doping in SPEs.
In this work, we have developed and explored poly(trimethylene carbonate) (PTMC) as a polymer host alternative for all solid-state Li-ion batteries. High-molecular-weight PTMC was synthesized via bulk ring-opening polymerization. Electrochemical and thermal properties of the PTMC/LiTFSI complexes with varied salt concentration were systematically investigated using electrochemical impedance spectroscopy (EIS) and thermal analysis (DSC/TGA). The as-prepared SPEs are amorphous materials and thermally stable up to 200 °C. The best-performing electrolyte could display useful ionic conductivity at elevated temperatures and was also found electrochemically stable towards 5.0 V vs. Li+/Li. The cycling performance of Li | SPE | LiFePO4 half cells has been tested at elevated temperatures and the cells display long-term cycling stability with retained high capacity up to 153 mAh/g. The gradual increase in capacity might be due to improved interfacial contacts during cycling and storage [3].

Acknowledgements

This work has been supported by the STandUP for Energy project and KIC InnoEnergy.

References

[1] B. Scrosati, J. Garche, J. Power Sources, 195 (2010) 2419.
[2] a) Smith, M. J. et al. Solid State Ionics, 140 (2001) 345; b) Silva, M. M. et al. J. Power Sources, 111 (2002) 52; c) Silva, M. M. et al. Electrochim. Acta, 49 (2004) 1887; d) Silva, M. M. et al. Solid State Sci., 8 (2006) 1318; e) Barbosa, P. C. et al. Solid State Ionics, 193 (2011) 39.
[3] B. Sun, J. Mindemark, K. Edström, D. Brandell, Solid State Ionics (2013), DOI: 10.1016/j.ssi.2013.08.014.
The Delithiation Behavior of LiFePO4 Particles with Broad Particle Size Distribution during Chemically Delithiation
Authors: Yoo Sunyoung , Kang Byoungwoo 
Published: February 2020

LiFePO4 is the most promising cathode material, especially for electric vehicle (EV) because of its inexpensive cost, superior thermal and structural safety, and non-toxicity. Although LiFePO4 has been believed to be poor conductor due to its low electronic conductivity and 1D lithium diffusion, nano-sized LiFePO4 shows the fastest electrochemical reaction during charge and discharge.
To understand these intriguing behaviors, we have to consider delithiation behavior of particles in the electrode which consists of 1010 ~ 1017 particles in addition to the transport properties in the material because a particle has a non-monotonic chemical potential[1]. The non-monotonic chemical potential of single particle in multi-particle electrode leads to characteristic electrochemical behaviors such as a flat potential in voltage curve of the electrode and a sequential phase transformation between particles. Thus, delithiation behaviors in a particle in the electrode should be understood.
In this study, we will explore delithiation behaviors of LiFePO4 with broad particle size distribution. For this purpose, chemical delithiation and followed centrifuge method were applied to understand the delithiation behavior of LiFePO4 depending on particle size. This simple method shows phase transformation behaviors more directly. We synthesized LiFePO4 with broad particle size distribution by solid state reaction. And then, we can easily separate chemically delithiated small and large particles by centrifuge method. In this talk, we will introduce simple centrifuge method and will discuss about delithiation behavior of LiFePO4 with broad particle size distribution during chemical delithiation.
[1] W. Dreyer et al 2010 The thermodynamic origin of hysteresis in insertion batteries Nature Mat.
9, 448.
Structual and Electrochemical Effects of Sn Addition on Si-Based Alloy Anod for Lithium Ion Batteries
Authors: Kim Min-Hyun , Choi Young-Pil , Kim Seon-Kyong , Park Cheol-Ho , Kim Yoon-Keun 
Published: February 2020

Various portable electronic devices are wildly used in the world due to the remarkable progress of information technology since 2000. It leads to the increasing demand for rechargeable batteries. As a result, Lithium Ion batteries (LIB) are intensively investigated by many researchers. Currently graphite-based anode materials have widely used. In order to extend to rapidly increasing demand and wider applications as electric vehicles, we have to develop a new anode material. Si-based alloy anode material is one of the strongest candidates because it has many advantageous properties such as high capacity, high safety, good electrochemical stability, and low production cost. M. Kim. et al.[1] has developed a good Si-base alloy anode material and they reported the structural and electrochemical properties[1]. The Si-base alloy is consisted of finely dispersed active silicon crystals and surrounding inactive metal matrix. The main role of inactive-matrix in Si-based alloy is suppressing the volume change and it helps the Si-based alloy maintain good cycle performance.
In this study, in order to enhance the cycle performance, we have added Sn metal which has theoretical capacity of 972mAh/g. Si and Sn nanocrystallites embedded in Si-Ti-Fe matrix were developed using arc melting followed by a rapid quenching method which could produce a large scale at one time. To identify the reaction mechanism, the ex-situ XRD, SEM, TEM, analyses were employed. Si and Sn nanocrystallites of approximately 100nm were dispersed in matrix composed of Si2TiFe. Consequently the Si/Sn/Si2TiFe composite showed a good cycle performance with 1000mAh/g over 50 cycles.
[1]Journal of electroanalytical Chemistry 687 (2012)84-88
New Synthesis Approach for High-Voltage Spinel LiNi0.5Mn1.5O4 a High Performance Positive Material for Lithium-Ion Batteries
Authors: Liu Haidong , Li Jie 
Published: February 2020

With the demand for increasing the energy and power, a lot of attention has been attracted by the LiNi0.5Mn1.5O4 (LNMO) spinel cathode material for lithium ion batteries, as it can be operated at a high voltage of ~ 4.7 V (versus Li+/Li) with offering 3-dimensional lithium-ion diffusion channels, allowing fast intercalation/deintercalation of lithium ions. However, it still remains challenging to get excellent rate capacity and cycling stability for LNMO material, especially at elevated temperature, due to the complex influencing factors and the undesired side reactions with the electrolytes. [1-5]

Various synthesis techniques, material modifications, and morphology control for high-voltage spinel LNMO have been reported to improve the electrochemical performance.[4-7] Such as cation doping, surface coating, and creating nanostructures. Meanwhile, the particle morphology of the material, especially the surface crystallographic planes, can also have an obvious influence on the electrochemical properties of material itself.
Herein, a new synthesis approach, allowing shorter material processing, will be presented, which leads to an achievement of special morphology of LNMO cathode material. The obtained LNMO material was characterized by means of X-rays diffractions (XRD), Raman spectrum, electron microscopy (SEM), and electrochemical measurements (CV, EIS, and galvanostatic charge-discharge test). The special morphology enables high-rate performance and cycle life simultaneously. The electrochemical performance was improved remarkably. Detailed discussion will be presented.
References
[1] Goodenough, J. B.; Park, K. S. J. Am. Chem. Soc. 2013, 135, 1167.
[2] Xiao, J.; Chen, X.; Sushko, P. V.; Sushko, M. L.; Kovarik, L.; Feng, J.; Deng, Z.; Zheng, J.; Graff, G. L.; Nie, Z.; Choi, d.; Liu, J.; Zhang, J. G.; Whittingham, M. S. Adv. Mater. 2012, 24, 2109.
[3] Duncan, H.; Duguay, D.; Abu-Leddeh, Y.; Davidson. I. J. J. Elecrochem. Soc.2011, 158, A537.
[4] Chemelewski, K. R.; Lee, E.; Li, W.; Manthiram, A. Chem. Mater.2013, 25, 2890.
[5] Zhang, X.; Cheng, F.; Yang, J.; Chen, J. Nano Lett. 2013, 13, 2822.
[6] Shaju, K. M.; Bruce, P. G. Dalton Trans.2008, 5471.
[7] Zhou, L.; Zhao, D.; Lou, X. Angew. Chem., Int. Ed. 2012, 51, 239.