bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Metal-Ion Adsorbent Based on Composite of Graphene Oxide/Poly (1-(3-aminopropyl) Pyrrole)
Authors: Qin Hongyi , Gong Tao , Cho Yujin , Lee Changgu , Kim Taesung 
Published: February 2020

A novel metal-ion adsorbent was developed based on graphene oxide (GO) and poly (1-(3-aminopropyl) pyrrole. Firstly, GO was covalently functionalized by 1-(3-aminopropyl) pyrrole (APP) monomer by an esterification reaction between the carboxyl groups of GO and the amine groups of APP. Subsequently, a GO/poly (1-(3-aminopropyl) pyrrole) (poly (GO-APP)) composite was prepared by in situ crosslinking polymerization.
The chemical structure of poly (GO-APP) composite was determined by a series of characterization methods, such as Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) and Thermogravimetric analysis (TGA).
The poly (GO-APP) was a hard solid material like a coal (Figure a), which is due to the crosslinked polymerization between GO and polymer. In this composite system, the GO is a crosslinking agent like a polyfunctional monomer, which can turn the linear polymer into crosslinked network polymer to increase the stiffness, strength and stability of poly (GO-APP).
This poly (GO-APP) composite is used for the adsorption of metal ions. As shown in Figure b, the absorption capacity of poly (GO-APP) was much larger than that of GO. The sorption of metal ions is based on both nitrogen and oxygen functional groups. The oxygen-containing functional groups in GO and the protonated amine groups in APP can bind to cations easily. Moreover, the chemical affinity of metal ions for amine groups is stronger than that for oxygen-containing functional groups. Therefore, the absorption capacity increases with the content of APP monomer.
Besides, the poly (GO-APP) showed a conducting property due to the conjugated π-π system in the main chain of copolymer, which will greatly expand the application fields of poly (GO-APP) composite.
Electrochemical Behavior of Carbon Nanostructured Electrode Material for Supercapacitor Application
Authors: Prakash Ramakrishnan , Shanmugam Sangaraju 
Published: February 2020

Electrochemical capacitors or supercapacitor (SCs) have been considered as one of the most promising energy storage devices for portable electronics, hybrid electric vehicles and stand-by power system. Especially in electric vehicles, SCs can couple with a fuel cell or battery to store and deliver the energy at a short period of time. Since, SC stores energy by electrostatic interaction between electrode-electrolyte interfaces based on the Electrical double layer phenomenon, so the amount of charge stored directly dependent on the surface area of any electrode material [1,2]. Porous carbon material recognized as a potential electrode material for SC owing to large surface area, chemical stability and low cost [3]. A large variety of porous carbons, such as activated carbons, aerogels, templated carbons, carbide-derived, carbon nanotubes, graphene and carbon nanofibers have been studied as EC electrode materials. However, many of the carbonaceous materials showed disadvantages such as the high ionic resistance, low electrical conductivity and low compatibility of conductive pathways to store charge, which unfavorable for high energy storage and high power devices criteria. So the performance of ECs does not only depends on the physical, but also intimately on the chemical properties of the electrode material. So the strategy of pseudocapacitance is required in the carbon framework. It has been reported that hetero atom (N, S, P and B) doping on carbon structure enhances the surface wettability as well as the electronic conductivity of the materials without compromising the long term cycle stability [4].
In the present work, we have investigated the morphological effect of nitrogen doped three different carbon nano-structures. Different nano-structures electrode materials such as rod, hollow and boat shaped are prepared using a coaxial electro-spinning technique and followed by carbonization, under inert (Ar.) atmosphere. The x-ray diffraction, Raman spectroscopy, x-ray photo-electron microscopy and high resolution transmission electron microscopy results reveal the synthesized carbon materials exhibit turbo-static carbon with poor sp2 graphitic carbon. The electrochemical properties of all the three electrode materials have been studied using cyclic voltammogram and galvanostatic charge-discharge using a symmetric type two electrode system configuration with aqueous as electrolyte medium, and analyzed to know their electrochemical properties. Long term cycle stability tests show excellent capacity retention.

References

(1). A. S. Arico, B. Scrosati, J. M. Tarascon, W. Van Schalkwijk, Nat. Mater., 4 (2005) 366-377.
(2). R. Kotz, M. Carlen, Electrochim. Acta., 45, (2000) 2483-2489.
(3). E. Frackowiak, F. Be´guin, Carbon, 39 (2001) 937-950.
(4). D. Hulicova, M. Kodama, H. Hatori, Chem. Mater., 18 (2006) 2318-2326.
Electrochemical and Thermal Characterization of a Graphene-Based Electrochemical Double-Layer Capacitor (EDLC)
Authors: Kang Jin Hee 
Published: February 2020

Graphene-based electrodes are of great interest for developing high performance electrochemical double-layer capacitors (EDLCs) due to their excellent electrochemical properties, low electric resistance and unique structures. Meanwhile, EDLCs have become more attractive not only to offer high power and energy densities but also to withstand a harsh temperature ranges [1]. Since temperature effects can be crucial to estimate the rational evaluation of degradation, energy efficiency and lifetime, it requires better understanding of temperature-dependent electrochemical properties especially at electrode/electrolyte interfaces. In this study, the performance of an EDLC, assembled with two identical graphene electrodes and the 1M Et4NBF4/PC electrolyte in a coin cell, is systemically characterized under various operating temperature conditions, ranged from -30 °C to 60 °C. Graphene deposition is carried out by using the vacuum filtration method. This method yields an electrically strong conductive and thermally stable nano-structured graphene paper [2]. Electrochemical characterization techniques including cyclic voltammetry (CV), constant charging/discharging (CCD) and electrochemical impedance spectroscopy (EIS) are performed to evaluate capacitance retention, energy and power densities, internal resistance variation and interfacial processes at the double-layer region. In addition, EIS data is simulated with the proposed electric equivalent circuit in order to investigate the temperature dependency on interfacial reactions with respects to mass transfer (diffusion) and electrode kinetics (charge transfer) [3]. Each reaction is represented by electrical resistive elements in the equivalent circuit, and its values are correlated with the activation energy to quantitatively rationalize the observed behaviour of diffusion and the charge transfer kinetics with temperature.

References:

[1] R. Kotz, M. Hahn, R. Gallay, Journal of Power Sources, 154 (2006) 550-555.
[2] H. Chen, M.B. Mueller, K.J. Gilmore, G.G. Wallace, D. Li, Advanced Materials, 20 (2008) 3557.
[3] J.W. Jinhee Kang, Shesha H. Jayaram, Aiping Yu, Xiaohui Wang, Electrochimica Acta, 115 (2014) 587-598.
Ultrafast Nano-Crystalline and Highly-Dispersed-TiO2 (B) /CNF Composites for Negative Electrode of ‘Nanohybrid Capacitor’
Authors: Iwama Etsuro , Abe Masayuki , Furuhashi Takumi , Abe Yuta , Miyamoto Junichi , Naoi Wako , Naoi Katsuhiko 
Published: February 2020

We have been applying our original in-situ material processing technology called ‘Ultra-Centrifuging (UC) Treatment’ to prepare a novel ultrafast nano-crystalline Li4Ti5O12 (nc-LTO) /carbon nano fiber (CNF) composite electrode for the generation-II capacitive energy storage device of ‘Nanohybrid Capacitor’ producing more than triple  energy density of a conventional electrochemical capacitor.[1] For the further improvement in the energy density of ‘Nanohybrid Capacitor’, LTO alternatives are needed. Among different candidates, TiO2 (B) possesses several advantages such as its 2-folds theoretical capacity (335 mAh g-1) of LTO (175 mAh g-1) and the comparable redox potential (1.6 V vs. Li/Li+). In addition, TiO2 (B) is an industrially attractive material because of its inexpensive raw materials and its environmentally benign synthesis using only aqueous solution (e.g., water-soluble complexes [2]) without any Li-sources.[2-4] However, TiO2 (B) has intrinsic problems; its low electronic conductivity and Li+ diffusivity due to the b-axis oriented growth of TiO2 (B) [3]. In this report, we successfully synthesized b-axis shortened and hyper-dispersed nc-TiO2 (B)/CNF composites, which has a potential to substitute nc-LTO/CNF as a negative electrode of ‘Nanohybrid capacitor’. Inhibition of b-axis growth and hyper dispersion of TiO2 (B) into the carbon matrix were simultaneously achieved by the UC treatment and the subsequent hydrothermal method [4]. The prepared nc-TiO2/CNF exhibited 236 mAh g-1 (active material) at high rate of 300 C, which even exceeds that of nc-LTO/CNF composites. A significant decrease of peak intensity corresponding to the C-site intercalation around 2 V vs. Li/Li+ indicates that the Li+ was directly accommodated into A1 and A2 site of TiO2 (B) owing to the limitation of b-axis growth. Furthermore, the combined analysis of the N2 adsorption experiment and electochemical characterization suggests that the "dispersibility" of nc-TiO2 (B) on CNF matrix correlates closely with its electrochemical performance.

References

[1] K. Naoi, et al., Energy & Environ. Sci., RSC, 5, (2012) 9363.
[2] a) M. Kobayashi,
et al., Chem. Mater., 19, (2007) 5373.
[3] A. R. Armstrong et al., Chem. Mater., 22, (2010), 6426.
[4] Y. Ren,
et al., Angewandte. Chem. Int. Ed, 51, (2012) 2164.
Cycle Stability of Manganese Dioxide Polymorph Supercapacitors at Elevated Temperature
Authors: Wu Nae-Lih , Pan Hsiao-An , Ghodbane Ouassim , Favier Frederic 
Published: February 2020

Electrochemical supercapacitors are of great interest as complementary electrochemical storage devices in the applications that require high power pulses. Many compounds have been investigated as possible supercapacitor materials, and manganese dioxides are certainly among the most attractive candidates. This is mainly due to their low cost, environmental compatibility and appropriate electrochemical performances. The chemistry of MnO2 is abundant with a variety of structural types. In the field of supercapacitors, the structural complexities exhibited by the 1D, 2D or 3D arrangement of MnO2 materials result in various charge-storage performances [1]. We have previously revealed the crystallographic evolution of the MnO2 polymorph supercapacitors taking place during the course of electrochemical charge/discharge [2], pointing out different cell expansion/contraction behaviors pertaining to their crystal structures. In many potential applications, such as electric vehicle and stand-alone renewable energy storage, supercapacitor cells are likely to constantly operate under elevate temperatures. Unfortunately, the high-temperature cycling stabilities of many pseudocapacitve supercapacitors, including MnO2, have essentially not been looked into in the literature.
In this study, the high-temperature (50 oC) electrochemical performances, in particular cycling stability, of supercapacitos made of three different MnO2 polymorphs, including cryptomelane, birnessite and spinel, with aqueous K2SO4 electrolyte were investigated. The samples were subjected to different analyses, including electrochemistry cyclic voltammetry, synchrotron X-ray diffraction, and synchrotron X-ray absorption spectroscopy, in order to reveal the predominant fading mechanisms both at 25 oC and 50 oC. It is shown that for all three polymorphs, the capacitance fading rates at 50 oC are far greater than those at 25 oC. It is further evidenced that their capacitance fading mechanisms at high temperatures are strongly affected by their crystallographic structure and the volumetric variation behavior previously disclosed.
[1] O. Ghodbane, et al. ACS Appl. Mater. 1 (2009) 1130.
[2] O. Ghodbane, et al. J. Power Sources 206 (2012) 454
Highly Luminescent Monolayers Prepared by Molecular Layer Deposition
Authors: Räupke André , Albrecht Fabian , Maibach Julia , Behrendt Andreas , Polywka Andreas , Heiderhoff Ralf , Helzel Jonathan , Rabe Torsten , Johannes Hans-Hermann , Kowalsky Wolfgang , Mankel Eric , Mayer Thomas , Görrn Patrick , Riedl Thomas 
Published: February 2020

Molecular layer deposition (MLD) is a solvent-free technique to prepare organic molecular layers with a similar level of control and perfection as that known from inorganic films grown by atomic layer deposition (ALD). In both, MLD and ALD, the deposition process relies on the self-limiting chemical reaction of two precursors on the surface of the substrate. A plethora of MLD processes has been demonstrated.[1] Among them, hybrid materials made from typical metal-organic precursors and alcohols, so called metalcones, have received considerable attention.[2] However, there is only very limited work on MLD of molecular systems which provide functionalities like charge transport or luminescence.[3; 4]
In our work, a general avenue for the controlled preparation of conformal and highly luminescent monolayers of metal chelate complexes is presented, among them tris(8-hydroxyquinolinato)aluminium (Alq3) and bis(8-hydroxyquinoline)zinc (Znq2). Alq3 is an extremely important model compound for organic electronic applications - it has been the electron transporter and luminescent material in the first efficient hetero-structure organic light emitting diode (OLED). The controlled formation of Alq3 or Znq2 monolayers is achieved by functionalization of the substrate with amino groups which serve as initial docking sites for trimethyl aluminum (TMA) or diethyl zinc (DEZ) molecules which datively bind to the amine (see figure).[5] Subsequent exposure to 8-Hydroxyquinoline (8-HQ) results in the self-limiting formation of highly luminescent monolayers on arbitrary surfaces, e.g. curved 3D objects or highly porous silica aerogels. The growth mechanism is studied by in-situ quartz crystal microbalance and ex-situ by highly sensitive (time-resolved) optical absorption/emission spectroscopy and photo-electron spectroscopy. Applications of these thin conformal luminescent layers will be discussed.
[1] S.M. George, B. Yoon, R.A. Hall, A.I. Abdulagatov, Z.M. Gibbs, Y. Lee, D. Seghete, B.H. Lee, in, Atomic Layer Deposition of Nanostructured Materials, Wiley-VCH Verlag GmbH & Co. KGaA, 2011, pp. 83-107.
[2] B.H. Lee, B. Yoon, A.I. Abdulagatov, R.A. Hall, S.M. George, Advanced Functional Materials 23 (2013) 532-546.
[3] O. Nilsen, K.R. Haug, T. Finstad, H. Fjellvåg, Chemical Vapor Deposition 19 (2013) 174-179.
[4] O. Nilsen, K. Klepper, H. Nielsen, H. Fjellvaåg, ECS Transactions 16 (2008) 3-14.
[5] A. Räupke, et al., ACS Applied Materials & Interfaces 6 (2014) 1193-1199.
In-Situ Studies on 2D Materials
Authors: Wallace Robert M 
Published: February 2020

The investigation of 2D materials such as graphene and transition metal dichalcogenides for beyond CMOS device concepts emphasizes the importance of surface and interfacial reactions. A fundamental understanding of such reactions in the context of materials integration for devices greatly benefits from in-situ characterization methods where processes such as surface cleaning, film deposition, and annealing can be simulated and subsequently correlated to device behavior. This invited talk will review our recent work on in-situ characterization of 2D materials in the context of device applications and the correlation of the physical and electrical characterization.
This research is supported in part by the STARNet Center for Low Energy Systems Technology, sponsored by the Semiconductor Research Corporation (SRC) and DARPA, the SWAN Center sponsored by the SRC Nanoelectronics Research Initiative and NIST, and by an IBM Faculty Award.
Absolute Value Determination of Vacancy Concentration in Silicon Crystals Using Low-Temperature Ultrasonic Measurements
Authors: Yamada-Kaneta Hiroshi , Okabe Kazuki , Akatsu Mitsuhiro , Baba Shotaro , Mitsumoto Keisuke , Nemoto Yuichi , Goto Terutaka , Saito Hiroyuki , Kashima Kazuhiko , Saito Yoshihiko 
Published: February 2020

For the samples taken from the void region of the CZ silicon crystal having various thermal histories, we performed the low-temperature ultrasonic measurements for the relative magnitude S of the elastic softening, which is proportional to the concentration of the single vacancies [Vs], i.e. [Vs] =g
S. Here, g is the proportionality constant to be determined below. We also carried out void observation by means of the infrared light-scattering tomography, which gave us the information on the concentration and size of the voids (i.e., the size distribution of the voids), from which we calculated the concentration of the vacancies [Vc] consumed for the void formation. From the result of these two experiments, we have found that the formula [Vc]+
a
S = U holds for the samples belonging to the same value of the crystal-growth parameter v/G. Here, a is the obtained numerical value, and U is the obtained function of the crystal-growth parameter. When we reasonably assume that, in the void region, the sum [Vc]+[Vs] is the function of the crystal-growth parameter: [Vc]+[Vs]= W(v/G) , then we find U= W(v/G), which further leads us to the present conclusion, g = a. Using this obtained value of g, we can determine the absolute value of [Vs] from [Vs] =g
S. Some examples of determining the absolute values of [Vs] are demonstrated.
We will also represent briefly our completely new technique of measuring the vacancy concentration in the near surface region of the silicon wafers. In this technique, the elastic softening due to the near-surface vacancies is selectively observed by the surface acoustic wave, instead of the bulk sound wave used for the above-mentioned measurement.
Overcoming High Performance Semiconductor Packaging Challenges Using Plasma
Authors: Foote David 
Published: February 2020

Moore’s Law has been the driving force of front end semiconductor technology development for over 40 years and is finally meeting its match. Technology demands, though, will not allow a slow down so the back end packaging technology needs to pick up the slack. Packaging technologies are now more like the front end chip technologies of 30 years past. Thirty years ago plasma processing was at best at the toddler stage in front end fabs while commonplace now. Thirty years hence plasma is at a similar stage in the back end packaging arena. Plasma processing enables the high performance packages required today.
Plasma is useful for both the manufacturing process of the packages as well as in the assembly of the package. High density interconnect assemblies are build on printed circuit assemblies that have had plasma processing to enhance adhesion between laminate layers as well as cleaning the through holes prior to plating.
Wafer level packaging is melding the front and back ends and plasma processing is enabling. The dimensional requirements are still such that high performance front end plasma processing techniques are not required but moving from the era of mils to microns does demand high performance from the plasma processing tool. Useful plasma processes for WLP include resist descum and strip, pre-bump cleaning and copper stud oxide reduction.
Optimized plasma processes enable three dimensional packaging technologies that are both useful and reliable. Flip chip packaging is becoming the norm at the leading edge and plasma enables better bondability and more reliable packages. Likewise plasma pre-treatment prior to wire bonding enables more robust and reliable bonds. Proper treatment levels enable robust bonds even on advanced packages of today with very thin metal stack for bonding. Plasma treatments are also useful for silicon stress reduction following wafer thinning and/or dicing.
Specific application examples will be presented showing the many uses and benefits of plasma processing for semiconductor packaging.
Effect of Cupric Methanesulfonate on through-Hole Filling by Copper Electroplating
Authors: Ye Ji-Xun , Dow Wei-Ping 
Published: February 2020

Through-hole (TH) filling of a printed circuit board (PCB) by copper electroplating was performed using copper sulfate (CuSO4) in recent years. However, the process might cause crystallization issue of CuSO4 because of extremely high CuSO4 concentration (i.e., 220g/L). In the other words, CuSO4 concentration cannot be increase anymore, if someone wants to enhance the copper filling rate inside the TH by increasing plating current density.
The anions of cupric methanesulfonate ( Cu(CH3SO3)2 ) is CH3SO3
-, which is different from copper sulfate (CuSO4). The solubility of cupric methanesulfonate is much higher than CuSO4, so that we can increase the current density and decrease plating time for TH filling by means of increasing cupric methanesulfonate concentration.
In this work, we employed the butterfly filling formula[1] to perform the TH filling. The copper source was changed from CuSO4 to Cu(CH3SO3)2 in order to increase copper ion concentration. The result show that with the high concentration of copper ion, we can enhance the copper filling rate inside the TH by increasing plating current density. Moreover, the copper thickness deposited on the board surface is not increased and the filled TH is void-free when the plating current density is increased.
Keywords: Through-hole filling, Printed circuit board, Leveler, Cupric methanesulfonate

References

1. J. J. Yan, L. C. Chang, C. W. Lu, and W. P. Dow, “Effects of organic acids on through-hole filling by copper electroplating
”, Electrochim. Acta. 2013, 109, 1– 12.