bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Nucleation and Growth of Binary Antimony Telluride Compounds
Authors: Sides William D. , Huang Qiang 
Published: February 2020

Whereas antimony telluride based compound materials have been demonstrated to be suitable for phase change memory devices,[1] among other applications, and are well suited to be fabricated via an electrochemical route, the ability to electrodeposit high quality thin films of these materials requires a good understanding of the nucleation and growth behavior that defines the initial stages of growth of these films.[2-4] Although electrochemical nucleation has been studied for decades,[5] little attention has been paid to the behavior of codeposition systems, where two or more materials are deposited simultaneously from a single electrolyte bath. In this study, the nucleation of Sb-Te compound is studied on gold and glassy carbon electrodes, to determine how the nucleation behavior of each element contributes to that of the overall system. Additionally, the effect of applied potential and electrolyte concentrations on the nucleation behavior and deposit composition is studied.
Cyclic voltammetry coupled with quartz crystal microbalance measurements are used to extensively study the deposition processes that occur during compound electrodeposition. It is seen that deposited Te is further reduced to a soluble species near the potentials required to deposit Sb, however the presence of Sb in the deposited film seems to hinder the further reduction to a soluble species, enabling compound film growth (figure 1). Additionally, the free energy released by compound formation allows the compound to be formed at potentials positive to those normally required for Sb deposition. Chronoamperometry, along with TEM-EDS analysis of the composition gradient of individual nucleation sites will be presented and discussed in conjunction with the CVs to understand the nucleation and growth of binary Sb-Te compounds.

REFERENCES

1. Raoux, S.; Wuttig, M., Phase Change Materials: Science and Applications. New York : Springer Dec. 2008: 2008.
2. Huang, Q.; Kellock, A. J.; Raoux, S., Electrodeposition of SbTe Phase-Change Alloys. Journal of The Electrochemical Society
2008,
155(2), D104-D109.
3. Catrangiu, A. S.; Sin, I.; Prioteasa, P.; Cotarta, A.; Cojocaru, A.; Anicai, L.; Visan, T., Studies of antimony telluride and copper telluride films electrodeposition from choline chloride containing ionic liquids. Thin Solid Films
2016,
611, 88-100.
4. Jung, H.; Myung, N. V., Electrodeposition of antimony telluride thin films from acidic nitrate-tartrate baths. Electrochimica Acta
2011,
56(16), 5611-5615.
5. Gunawardena, G.; Hills, G.; Montenegro, I.; Scharifker, B., Electrochemical nucleation. Journal of Electroanalytical Chemistry and Interfacial Electrochemistry
1982,
138 (2), 225-239.

Figure 1
Studies on the Interfacial Impedance of Superconcentrated Non-Aqueous Electrolytes in Contact with Li-Ion Conductive Ceramic Membranes
Authors: Arruda Thomas M , Donnelly Daniel J , Patrissi Charles J. 
Published: February 2020

Superconcentrated nonaqueous electrolytes have recently received considerable attention for their various unusual functionalities within rechargeable batteries.1,2 These include high reductive and oxidative stabilities and enhanced thermal stability of the solvent. Our research focuses on the interfacial effects of superconcentrated lithium salts in aprotic solvents, on ceramic Li-ion conductive membranes of varying porosity. Electrochemical impedance spectroscopy was employed with a four-electrode setup to study the interfacial kinetics, and was processed by analyzing the Nyquist plots. These methods revealed promising trends that may lead to the finding an optimal concentration range of LiTFSI in DMC solvent with high porosity ceramic membranes, that would minimize interfacial impedance. This presentation will highlight some of our recent findings.
1. Y. Yamada, M. Yaegashi, T. Abe, and A. Yamada, Chem. Commun., 49, 11194–11196 (2013) http://dx.doi.org/10.1039/C3CC46665E.
2. Y. Yamada and A. Yamada, J. Electrochem. Soc., 162, A2406–A2423 (2015) http://jes.ecsdl.org/content/162/14/A2406.abstract.
Bi-Continuous Nanoporous Metal Formation Via Compound Decomposition
Authors: Chen Qing , Wang Congcheng 
Published: February 2020

The spontaneous formation of bi-continuous nanoporous (BNP) metal from dealloying, i.e. the selective dissolution of an alloy, has fascinated generations of researchers to pursue its significance in corrosion and, increasingly, in catalysis. As the structure possess interpenetrating pores and metal ligaments at length scales down to a few nanometers, it provides a large yet highly accessible area comprising a high population of surface steps; these attributes promote BNP metal as the best catalysts for a variety of catalysis challenges. However, one of the obstacles facing a wider application of the BNP metal is the demanding preparation of the starting materials, i.e. a homogeneous alloy. Here we present that the step of alloy preparation can be completely eliminated from the fabrication of BNP metal by adopting an alternative route of reduction-induced decomposition. In this decomposition process, ionic or covalent compounds (e.g. AgCl and CuO) can be chemically reduced to form BNP metal similar if not identical to that through dealloying. We use a combination of characterization techniques, including electron microscopy, underpotential deposition-based area measurement, and small-angle X-ray scattering, to show the structural resemblance of the decomposed materials to their dealloyed counterparts. At the same time, the differences between the two types of structures and their potential structural and functional impacts will also be discussed. We believe that the introduction of decomposition as a low-cost yet flexible alternative will enable a wide adoption of BNP metal as active yet affordable catalysts.
McCue, I.; Benn, E.; Gaskey, B.; Erlebacher, J. Annu. Rev. Mater. Res.
2016, 46 (1), annurev-matsci-070115-031739;
Chen, Q. J. Electrochem. Soc.
2014, 161 (10), H643–H646.
Use of Microdischarge Lithography for Development of Organic Electronic Devices over Large Areas
Authors: Alvarez Angel Luis , Borrás Fernando , Moreno Jorge Sebastián , García-Vélez Miguel , Jiménez-Trillo Juan , Coya Carmen 
Published: February 2020

The concept of 'displays everywhere', which may be extended to wearable sensors, signal tags or energy devices, implies ubiquity of electronic devices not only in walls or appliances but integrated in all kind of domestic objects, such as clothes, bags or wrappings, and is expected to preside over our daily lives in the near future. For this expectation to succeed, Electronics industry must face compatibility with three new paradigms: flexible substrates -to be adapted to different surfaces and geometries-, large areas (eventually up to square meters), and lightness. In any case, this revolution can only take place from a drastic reduction of the production costs. As it is well known, these paradigms are difficult to access solely for conventional microelectronics technology based on silicon or other crystalline materials, and many alternatives based in new materials and procedures have been proposed. Thus, a manufacturing facility based in the roll-to-roll (R2R) technology is considered a suitable candidate to achieve high yield over large areas in a cost effective way. In consequence, those patterning techniques compatible with R2R production lines are receiving enhanced attention.
In this contribution, we exploit the possibilities of a dry and subtractive lithography based on electrical microdischarges to pattern both electrodes, cathode and anode, of organic devices, particularly displays based in organic light emitting diodes (Fig. 1). Using a homemade prototype rated at technology readiness level 4, we demonstrate that electrical discharge lithography may overcome many obstacles such as tilt correction and relocation after processing, avoiding the use of masks and many of the photolithographic steps. This is thanks to the electrical monitoring during operation as well as a precise electronic control of the position, with 1 µm reproducibility. Since sparks are very fast processes (range of few µs or less) features may be performed at speeds of tens mm/s, ensuring scalability to large areas (cms), and hence compatibility with high throughput manufacturing lines. Of particular interest results patterning of graphene as electrode, due to the practical absence of residues under electrical discharges. Other advantages and drawbacks will be discussed, as well as physical aspects involved.

Figure 1
Effect of Inserting Nanoscale-Thick Inorganic Interlayer Between Metal Electrode and Organic Layers on Photo-Sensitivity Enhancement of Organic Photo Diodes
Authors: Park Joo-Hyeong , Song Seung-Hyun , Kim Min-Won , Kown Hyo-Jun , Kim Jae-Gon , Jung Ui-Hyeon , Baik Hyo-Won , Park Jea-Gun 
Published: February 2020

The conventional silicon based photo diodes have high photoelectric conversion efficiency and photosensitivity. However, inorganic based photo diodes have a low visible-wavelength sensitivity due to their infrared-wavelength absorption. Recently, organic based photo diodes (OPDs) have been greatly attracted due to their flexibility, a low production cost, and a high photosensitivity in visible wavelength ranges.[1, 2]

In this work, we investigated the effect of inserting inorganic interlayer between metal electrode and organic layers in order to enhance photosensitivity of OPDs. The device structure was consist of vertically stacted bottom indium-tin-oxide (ITO) electrode/bottom inorganic interlayer (NiOx)/organic layer (DMQA:Me-PTC)/top inorganic interlayer (MoOx)/top aluminum electrode on a glass substrate. The bottom NiOx inorganic interlayer was inserted between bottom ITO electrode and DMQA:Me-PTC photo-organic layer and its thickness was varied from 1 to 5 nm. It was found that the highest photocurrent/dark current ratio of OPDs was 1.34 x 104 at 4-nm-thick NiOx. In addition, the top MoOx:Al (1:1) inorganic interlayer was inserted between top aluminum electorde and DMQA:Me-PTC photo-organic layer and its thickness was varied from 1 to 3 nm. It was also observed that the highest photocurrent/dark current ratio was 4.51 x 104 at 2-nm-thick MoOx:Al. In our presentation, we will present the mechanism by which the photosensitivity is enhanced by varying inserted inorganic interlayer (NiOx or MoOx) via investigating the dependency of energy band gap on the inserted inorganic interlayer thickness and that of the chemical composition profiles of OPDs.

* This work was financially supported by LG Electronics Inc. and Brain Korea 21 Plus Program in 2017.

[1] Baeg, K.-J., Binda, M., Natali, D., Caironi, M. & Noh, Y.-Y. Organic light detectors: photodiodes and phototransistors. Adv. Mater. 25, 4267–4295 (2013).
[2] Yao, Y. et al. Plastic near-infrared photodetectors utilizing low band gap polymer. Adv. Mater. 19, 3979–3983 (2007)

Figure 1
Electrolyte Influence in Developing a High-Capacity, Reversible Lithium-Oxygen (Lithium-Air) Battery
Authors: Burke Colin M , McCloskey Bryan D 
Published: February 2020

The nonaqueous lithium-oxygen (also called lithium-air) electrochemistry has an extraordinarily high theoretical specific energy, but critical electrochemical challenges prevent the realization of a high-capacity, reversible battery. Consisting of a lithium-metal negative electrode, an anhydrous, organic solvent-based lithium electrolyte, and a gaseous oxygen-saturated porous carbon positive electrode, the battery operates via the formation and decomposition of lithium peroxide (Li2O2). Unfortunately, in the most stable, ether-based electrolytes studied to-date, Li2O2 forms as a thin film on the carbon surface. As Li2O2 is an insulator, the thin film quickly leads to a large increase in the surface overpotential, effectively shutting off the battery before a high capacity can be achieved. Additionally, both the most stable electrolytes and porous carbons studied to-date still exhibit electrochemical decomposition in the presence of Li2O2 in operating cells, leading to parasitic products and poor cyclability.
In this work, we present electrolyte salt and solvent considerations toward addressing these challenges. We will particularly focus on recent reports that the introduction of lithium iodide (LiI) salt to a water-contaminated ether-based electrolyte induces a 4e- per O2 reduction reaction forming lithium hydroxide (LiOH) rather than the typical 2e- per O2 reduction reaction forming Li2O2.1,2 This could potentially mitigate both charge transport and instability issues related to Li2O2 by entirely changing the discharge electrochemistry. We present our recent quantitative analysis of the influence of LiI and H2O on the electrochemistry in a typical ether-based Li-O2 battery via differential electrochemical mass spectrometry and titrations of extracted cathodes.3 We confirm that LiI and H2O promote the efficient production of LiOH on discharge, but we find that LiOH is not reversibly oxidized to O2 on charge. Rather, the charge electrochemistry is a complicated mix of redox shuttling and side reactions. We hope to inspire further research toward understanding the complex chemistry involved upon the addition of redox mediators to lithium-oxygen batteries.
(1) Liu, T.; Leskes, M.; Yu, W.; Moore, A. J.; Zhou, L.; Bayley, P. M.; Kim, G.; Grey, C. P. Science
2015, 350, 530.
(2) Kwak, W.-J.; Hirshberg, D.; Sharon, D.; Shin, H.-J.; Afri, M.; Park, J.-B.; Garsuch, A.; Chesneau, F. F.; Frimer, A. A.; Aurbach, D.; Sun, Y.-K. J. Mater. Chem. A
2015, 3, 8855.
(3) Burke, C. M.; Black, R.; Kochetkov, I. R.; Giordani, V.; Addison, D.; Nazar, L. F.; McCloskey, B. D. ACS Energy Letters
2016, 1, 747.
Properties of Ionic Liquids and Their Performance As Electrolytes for Sodium Batteries
Authors: Hilder Matthias , Saurel Damien , Gonzalo Elena Candida , Rojo Teófilo , Armand Michel , MacFarlane Douglas R , Howlett Patrick C , Forsyth Maria 
Published: February 2020

With the world facing a global energy crisis research efforts have been focussing on alternative energy storage solutions, A promising and inexpensive alternative to the dominating lithium battery technology are sodium batteries, which are particularly interesting for large scale energy storage.
Ionic liquids (ILs) are novel electrolyte systems which have the potential to be compatible to support the electrochemistry of sodium while replacing commonly used organic solvent electrolytes, thus improving the safety of such devices.
Here the physicochemical properties of three bis(fluorosulfonyl)imide (FSI) based ionic liquid electrolytes with small alkylphosphonium cations or an alkyletherammonium cation (P111i4FSI, P1i4i4i4FSI, N2(2O2O1)3FSI) were investigated including the thermal properties, ionic conductivity and viscosities. The phosphonium ILs showed particularly high conductivities (0.94mScm-1 for P111i4FSI at 50°C) while also having the highest decomposition temperatures (320°C). All IL solutions with NaFSI showed very stable Na symmetric cell cycling with low overpotentials (P111i4FSI:NaFSI 100mV at 1mAcm-2) making them promising electrolytes for sodium batteries.
The electrolytes were cycled against NaPO4 (NFP) cathodes and layered transition metal oxides (P2-Na2/3[Fe2/3Mn1/3]O2, O3-Na2/3[Fe2/3Mn1/3]O2, P2-Na2/3[Mn0.8Fe0.1Ti0.1]O2). The highest stability and capacity was observed for the P111i4FSI electrolyte, particular with the O3-Na2/3[Fe2/3Mn1/3]O2 cathode. Surprisingly the NFP electrodes showed very stable cycling.
On selected cells post-cycling analysis was performed. While the electrolyte is not compromised, there is spectroscopic evidence for the formation of a stabilising solid electrolyte interface on the sodium metal anode as well as on the cathode. In addition the cathode morphology changes.
In summary ionic liquid electrolytes match or out perform conventional organic solvent electrolytes in terms of performance at elevated temperatures, capacity, cycle stability and safety.
Electrochemical Characterization of Silicon Nanocrystals Embedded in Alloy Matrix As Anode Materials for Lithium-Ion Cells
Authors: Kim Sang-Hyung , Yook Seung Hyun , Kim Seon-Kyong , Park Cheol-Ho , Kim Dong-Won 
Published: February 2020

Silicon has been regarded as one of the most promising anode materials to increase the energy density of lithium-ion batteries by replacing graphite materials due to its high theoretical capacity.1 However, the practical application of silicon materials in lithium-ion batteries is hampered by the large volume changes that occur during repeated cycling, which result in the cracking of the electrode, loss of electrical contact, unstable solid electrolyte interphase (SEI) formation, and eventually rapid capacity fading upon cycling.2,3 The promising approach to overcome the above problems is the utilization of active-inactive alloy systems, where the electrochemical reaction occurs in the active phase and the inactive phases help to improve electronic conductivity and act as a volume buffer. In the present work, we synthesized silicon alloys composed of silicon nanoparticles embedded in Cu-Al-Fe matrix phases. The matrix phases have a mechanical property to endure the stress generated by the volume expansion of Si during cycling in addition to high electrical conductivity for fast electron transfer to silicon. This strategy resulted in enhanced cycling performance in terms of discharge capacity, capacity retention and rate capability. These superior performances could be attributed to its unique structure with silicon particle embedded by alloy matrix, which could effectively accommodate the large volume change during cycling and provide continuous electronic pathway in the electrode. Detailed characterization of the silicon alloy materials along with their electrochemical performance as anode in lithium-ion cells will be presented.

References

1. V. Etacheri, R. Marom, R. Elazari, G. Salitra and D. Aurbach, Energy Environ. Sci., 4, 3243 (2011).
2. B. Key, R. Bhattacharyya, M. Morcrette, V. Seznec, J.-M. Tarascon and C. P. Grey, J. Amer. Chem. Soc., 131, 9239 (2009).
3. M. T. McDowell, S. W. Lee, W. D. Nix and Y. Cui, Adv. Mater., 25, 4966 (2013) .
(Invited) Effect of Physisorbed Oxygen on the Photoluminescence of Single-Walled Carbon Nanotubes Suspended By Single-Stranded DNAs
Authors: Bachilo Sergei M. , Zheng Yu , Weisman R. Bruce 
Published: February 2020

For more than a decade, DNA and oligonucleotides of single-strand DNA (ssDNA) have studied as agents for dispersing single-walled carbon nanotubes (SWCNT), with the goals of potential biomedical applications and the selective sorting of specific (n,m) structures from as-produced inhomogeneous mixtures. We have recently discovered that SWCNTs suspended by ssDNA oligos in water show rather strong quenching from dissolved molecular oxygen. In many cases dissolved oxygen in equilibrium with 1 atm partial pressure of O2 decreases the SWCNT fluorescence intensity by a factor of two, and for some systems the quenching factor is two in air-saturated solutions and reaches three under 1 atm of pure O2. We find that the quenching depends on (n,m) species and ssDNA sequence, in addition to some other experimental parameters. The effect varies smoothly with dissolved oxygen concentration and is fully reversible on purging with other gases such as argon or nitrogen. The quenching effect appears and disappears on a sub-second time scale.
An important finding is that the extent of oxygen quenching correlates with the apparent affinity between the DNA oligo and the SWCNT species. Combinations thought to give strong coating show weak quenching, possibly because of reduced exposure of the nanotube surface to the surrounding solution. Thus, this effect can provide a simple way to identify special affinities just by measuring fluorescence changes when dissolved oxygen is displaced by inert gases. To help understand the mechanism of the quenching effect and its potential value in other applications, we have studied a variety ssDNA oligos, including those containing only one nucleotide. We have also studied the effect with other dispersing agents and surfactants, quantified the dependence of quenching on oxygen concentration, analyzed fluorescence spectral shifts caused by dissolved oxygen, and explored the quenching effect in solid nanotube films and in solutions modified by addition of polymers and other chemicals. We will present the results of those experiments and our proposed mechanism for the effect.
Carbon Nanotube Reinforced Structural Composite Supercapacitors
Authors: Westover Andrew S , Teblum Eti , Schauben Deanna , Yitzhak Anat , Muralidharan Nitin , Muallem Merav , Nessim Gilbert , Pint Cary L. 
Published: February 2020

Carbon nanotubes (CNT) lie at the crossroads of a multitude of different next generation technologies. Among the most promising of these are structural reinforcement of composites and high energy density supercapacitors. Our work presents a unique approach where CNT grown on stainless steel meshes are used to simultaneously mechanically reinforce a structural composite and function as a high energy density supercapacitor electrodes. The multifunctional design is enabled via an epoxy-ionic liquid matrix/electrolyte and with alternating layers of insulating fiberglass or Kevlar and CNT grown on steel mesh. The resulting composite energy storage devices exhibit mechanical strength greater than 85 MPa approaching that of commercial composites and with an energy density of up to 3 mWh/kg for a fully packaged system. Furthermore in-situ mechano-electro-chemical tests demonstrate that the capacitance is completely maintained throughout the elastic regime up to the maximum tensile loading >85 MPa.
(Invited) Ultrafast Spectroscopy of Doped Carbon Nanotubes
Authors: Hertel Tobias , Eckstein Klaus 
Published: February 2020

We will report on an investigation of exciton and trion dynamics in chemically- or electrochemically-doped semiconducting single-wall carbon nanotubes using VIS and NIR femtosecond time-resolved pump-probe spectroscopy.