bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Application of Impedance Spectroscopy for Perovskite Solar Cells
Authors: Murakami Takurou N 
Published: February 2020

Perovskite solar cells (PSCs) have reached over 20% efficiency. However, there is still room for improvement of the reproducibility of the solar cell performance in the PSCs. Also, PSCs still have unknown properties such as a hysteresis of I-V curve, effects of the porous layers in the electron transporting layer, and effects of aging. Characterization of the PSCs is essential to understand the electronic properties of the materials and their interfaces in PSCs. Currently, the general architecture for an efficient PSC with n–i–p configuration can be summarized as follows: transparent conductive oxide (TCO) as the electron-collecting layer / n-type semiconductor for the electron-transporting layer (ETL) / perovskite as the intrinsic material / p-type semiconductor for the hole-transporting layer (HTL) / metal as the hole-collecting layer. The photovoltaic performances of PSCs without an ETL or HTL are inferior to those with the standard PSC structure, indicating the important role of charge selection and transportation in the ETL and HTL. Impedance spectroscopy is powerful method for measurement of the resistance components and the capacitance in the electronics devices and is often used for characterizations of the PSCs. However, impedance spectra in PSCs are mostly used for supporting the presumption in the results without verification of the spectra assignment. On the other hand, there are reports to verify the impedance spectra of PSCs with the complexity equivalent circuits. Interpretation of the impedance spectra for PSCs with simple equivalent circuits is significant for the accurate characterization of PSC as a general method.
In this research, we prepared the model PSCs including the layer with different thickness and measured the impedance spectra of the model PSCs to understand the correspondence between the PSC architecture and spectra.
Synthesis and Applications of Monobenzoporphyrins
Authors: Kumar Sandeep , Sankar Muniappan 
Published: February 2020

Porphyrins are one of the most abundant macrocyle found in nature [1] which is playing a vital role in biological and material applications [2]. The push-pull porphyrins are used in dye-sensitized solar cells (DSSCs), nonlinear optics (NLO), ion-sensing and catalysis etc [3]. In this regard, MTPP(Benzo)CHO (M = Cu, Zn, Ni and Co) were prepared from the dibromo β-formyl porphyrin using Heck coupling followed by electrocyclization [4] for NLO applications. Further, cyanoacetic acid appended antipodal Zn(II) benzoporphyrin (Figure 1) was synthesized from β-formyl monobenzoporphyrin using Knoevenagel condensation reaction in order to utilize for DSSC application.
The UV-Visible absorption spectra of the ZnTPP(Benzo)CHCCNCOOH and the MTPP(Benzo)CHO (M = Cu, Zn, Ni and Co) and MTPPBr2CHO (M = Cu, Zn, Ni and Co) were compared, which show a red-shifted Soret and Q bands as compared to precursor porphyrins. Also, we have studied the electrochemical redox properties of both ZnTPP(Benzo)CHO and ZnTPP(Benzo)CHCCNCOOH. These porphyrins exhibited a cathodic shift in the first redox potentials as compared to ZnTPPBr2CHO. Similarly, CuTPP(Benzo)CHO exhibited a positive shift in the first oxidation potential and a negative shift in the first reduction potential as compared to CuTPPBr2CHO (Figure 1). In this presentation, we will describe the synthesis, spectral and redox properties of monobezoporphyrin derivatives and their application in DSSC.

Figure 1: Molecular structures of synthesized porphyrins and their comparative Cyclic voltammograms in CH2Cl2 using TBAPF6 as supporting electrolyte at 298 K.

References

1. Shao, S.; Rajendiran, V.; Lovell, J. F. Chem. Rev.
2017. 379, 99.
2. D. R.; Summerville, D. A.; Basolo, F. Chem. Rev. 1979, 79, 139.
3. (a) Kumar, R.; Sudhakar, V.; Prakash, K.; Krishnamoorthy, K.; Sankar, M. ACS Appl. Energy Mater.
2018, 1, 2793. (b) Prakash, K.; Sudhakar, V.; Krishnamoorthy, K.; Sankar, M. Dyes Pigm.
2019, 160, 386. (c) Prakash, K.; Manchanda, S.; Sudhakar, V.; Sharma, N.; Sankar, M.; Krishnamoorthy, K. Dyes Pigm.
2017, 147, 56. (d) Yadav, P.; Kumar, R.; Saxena, A.; Butcher, R. J.: Sankar, M. Eur. J. Inorg. Chem.
2017, 26, 3269. (e) Sonkar, P. K.; Prakash, K.; Yadav, M. Ganesan, V.; Sankar, M.; Gupta, R.; Yadav, D. K. J. Mater. Chem. A 2017, 5, 6263.
4. (a) Jinadasa, R. G. W.; Fang, Y.; Deng, Y.; Deshpande, R.; Jiang, X.; Kadish, K. M.; Wang, H. RSC Adv., 2015, 5, 51489. (b) Jiao, L.; Hao, E.; Fronczek, F. R.; Vicente, M. H.; Smith, K. M. 2006 ,37, 3900.

Figure 1
Vitamin B12 - a Bioinspired Catalyst for Organic Reactions
Authors: Gryko Dorota 
Published: February 2020

Nature constructs and decomposes complex molecules with the help of enzymes and light as the ultimate energy source. However, despite enzyme’s fundamental benefits, their industrial application can be limited by their availability, instability towards certain reaction conditions, cost, scale, lack of suitable enzyme etc. A complementary approach to sustainable methodologies relies on the formation or cleavage of chemical bonds using bioinspired methods (methods imitating the efficient and elegant designs of biology) and recruiting light, the most abundant free energy source.
Vitamin B12 - a cofactor of many enzymes seems inspirational.[1,2] This type of catalysis has been successfully translated into the laboratory and used in a small collection of reactions.[2, 3] The advantage of using vitamin B12 as a catalyst lays in the complete stability of the central cobalt ion and by the definition it is nontoxic. It has also been well documented that the reaction mechanism usually follows a radical pathway, bringing a new dimension to this already interesting field.
Along this line, we have developed new vitamin B12-catalyzed reactions involving reduction of Co(III) to Co(I) or Co(II) and subsequent reactions with electrophiles or radicals. Under light irradiation vitamin B12 derivative unusually catalyzes a new olefinic sp2 C-H alkylation reaction, with diazo reagents as a carbene source, instead of the expected cyclopropanation, acylation of activated olefins. Light-induced vitamin B12-catalyzed methods are also suitable for C-O bond cleavage.
These key findings emphasize the unique feature of vitamin B12 as a catalyst to achieve something unachievable with other methoologies or to find a greener approach.

Banerjee, R. Chemistry and Biochemistry of B12, John Wiley & Sons, Inc, 1999

K. ó Proinsias, M. Giedyk, D. Gryko, Chem. Soc. Rev.
2013, 42, 6605-6619.

Giedyk, M.; Fedosov, S.; Gryko, D. Chem.
Commun.
2014, 50, 4674-4676.

Figure 1
Charged Porphyrin Metal Complexes As Building Units of Ion-Pairing Assemblies and Materials
Authors: Maeda Hiromitsu 
Published: February 2020

π-Electronic ions with appropriate geometries and peripheral substituents provide assemblies through interactions between building subunits, resulting in fascinating electronic properties. Structures and properties of the assemblies can be controlled by the combined negatively and positively charged species in the assemblies. Thus far, diverse ion-responsive π-electronic systems and π-electronic ions have afforded dimension-controlled ion-pairing assemblies as crystals, supramolecular gels, and thermotropic liquid crystals (LCs).[1,2] Highly ordered arrangement of charged species has been found to be a key factor to exhibit the enhanced performance as fascinating electronic materials. In fact, ion pairs of porphyrin-AuIII complexes as π-electronic cations, prepared with the combination of various anions including a π-electronic anion, formed dimension-controlled assemblies as thermotropic liquid crystals, whose ionic components were highly organized by electrostatic and π–π stacking interactions.[3–5]
References

A recent review: Haketa, Y.; Maeda, H.Bull. Chem. Soc. Jpn.
2018, 91,420.

Recent examples: a) Maeda, H.;Takeda, Y.; Haketa, Y.; Morimoto, Y.; Yasuda, N. Chem. Eur. J.
2018, 24, 8910; b) Kaname, S.; Haketa, Y.; Yasuda, N.; Maeda, H. Org. Lett.
2018, 20, 3268; c) Maeda, H.; Okubo, T.; Haketa, Y.; Yasuda, N. Chem. Eur. J.
2018, 24, 16176; d) Yamakado, R.; Ishibashi, H.; Motoyoshi, Y.; Yasuda, N.; Maeda, H. Chem. Commun.
2019, 55, in press.

Haketa, H.; Bando, Y.; Sasano, Y.; Tanaka, H.; Yasuda, N.; Hisaki,I.; Maeda, H.to be submitted.

Assemblies of anionic porphyrins: Sasano, Y.; Yasuda, N.; Maeda, H. to be submitted.

As related species, chiral metal complexes of dipyrrins, with half structures of porphyrin, have exhibited long lifetime photo-excited triplet states: Hirata, G.; Kobayashi, Y.; Yasuda, N.; Maeda, H. to be submitted.
(Invited) Synthesis and Properties of All SWCNT Metallic Nanotube Wire
Authors: Lashmore David , Bystricky Pavel , Bulmer John 
Published: February 2020

Copper and aluminum wire conductors are the principal means of conducting electricity. However, they add weight, possess poor fatigue and corrosion resistance and suffer from electromigration under severe conditions. Carbon nanotube (CNT) conductors have long been thought able to replace metals but still fall short of copper in electrical conductivity. CNT wires have so far displaced metal conductors in only a few high value-added applications. In this presentation, we outline an approach to create CNT conductors that address copper shortcomings. These carbon-based wires are made by a new high rate process to grow all metallic (armchair) CNT single wall tubes which are spun into wire in situ within the reactor all in one step, thereby keeping air away from the contacting surfaces of the tubes. We discuss a model of growth in terms of entropy of formation and radiation induced sympathetic vibration.
In all other CNT yarn formation methods known to us, multistep processes are required which add cost or omit spinning. This latter process is necessary to add strength and improve conductivity. The innovations described in this talk include (1) methods for synthesis of nearly all metallic single chirality carbon nanotubes, and (2) the in situ spinning of these nanotubes within the reactor to a finished wire.
We describe their properties determined by Raman, TGA, and structure by SEM and TEM. The conductivity of CNT wires depends on CNT alignment, surface contamination, control over the interfaces (Schottky barriers), and density. Yarns made from nanotubes of exactly the same diameters are also expected to pack well in the wire and provide better properties than the more typical random and larger diameters sometimes made.
The combination of Boronite’s approach to create all CNT wire from uniform nanotubes with metallic chirality with the increasing commercial pressure to reduce weight, increase strength, and operational temperature, opens up commercial opportunities for very lightweight wiring in applications from aircraft to rotating machinery used at high temperatures. Weight saving in a variety of products is especially important for aircraft, cars, and even for large electric systems required to deliver very high current pulses. Boronite has also developed a unique method for infiltrating CNT spun yarn with copper, silver or aluminum to create electromigration resistant materials that can carry extreme currents.
Effect of Gap Size on Galvanic Corrosion between AA5052 Aluminum-Magnesium Alloy and SS400 Carbon Steel in Aqueous NaCl Solutions
Authors: Ota Kengo , Tada Eiji , Ooi Azusa , Nishikata Atsushi 
Published: February 2020

Recently, aluminum alloys (AAs) have been utilized to automobile body parts in order to reduce the weight of the body and improve fuel consumption efficiency. Although some aluminum alloys such as 5000 and 6000 series have relatively good corrosion resistance in atmospheric environments, galvanic corrosion between aluminum alloys and other electroconductive materials is one of the critical issues on automotive application of the aluminum alloys. So far, we have investigated galvanic corrosion between AA5052 aluminum-magnesium alloy and SS400 carbon steel in aqueous NaCl solutions and reported that the galvanic corrosion behavior changes depending on the concentration of NaCl solutions [1]. In this study, effect of gap size between aluminum alloys and steel on galvanic corrosion behavior was investigated in aqueous NaCl solutions.
A galvanic couple used in this study was almost the same as that reported before, which was made of AA5052 Al-Mg alloy (Mg: 2.65, Si: 0. 08, Fe: 0.27, Cu: 0.01, Cr: 0.17, Zn: 0.01, Al: bal. (mass%)) and carbon steel (JIS SS400). The plate of both materials was 10-mm width and 15-mm length and 5-mm thickness. After lead wires were connected to each plate, both plates were embedded together in an epoxy resin. In this study, both plates were placed separately along the surface with gap sizes from 500 um to 10 mm so that a coplaner galvanic couple was prepared. The surface of the galvanic couple was ground with SiC papers up to JIS 2000 grit and rinsed in EtOH. Galvanic corrosion experiments were done for 72 h in aqueous NaCl solutions of various concentrations ranging from 5 mM to 2 M. Galvanic current and corrosion potential of the couple were measured during the immersion in the solutions.
It was found from the results of corrosion potential, galvanic current, and surface observation that galvanic corrosion behavior changes depending on the gap size between AA5052 and SS400 in the NaCl solutions. When the gap size was 10 mm, no corrosion occurred on the SS400 side in all of the test solutions, suggesting that anodic dissolution reaction was dominant on the AA5052 side. However, when the gap size was decreased, the corrosion of the steel occurred in the solutions at lower concentrations, although the aluminum alloy also showed localized corrosion. These results indicated that anodic dissolution reaction was generated on both materials in the smaller gap-size condition with decreasing the NaCl concentrations. In this study, the change in the galvanic corrosion behavior with the gap size was also discussed from the results of change in the solution chemistry and polarization behavior of the materials.
1. K. Ota, E. Tada, A. Ooi, A. Nishikata, ECS meeting abstracts, MA2018-02, 574, 2018.
The Corrosion Behavior of 50-Kg As-Cast Fecrnicomnx Alloys
Authors: Hsu Kuo-Min , Lin Chao-Sung 
Published: February 2020

FeCrNiCoMn, one familiar type of high entropy alloys, has drawn much attention due to its interesting mechanical properties at cryogenic temperatures. In this research, the microstructure and corrosion behavior of 50-kg as-cast FeCrNiCoMnx alloys were studied. The X-Ray Diffractometer (XRD) results show that both alloys are single fcc structures. The influence of manganese content on the corrosion behavior of FeCrNiCoMnx was investigated using electrochemical methods in H2SO4 and NaCl solutions. Dendritic structures were observed in each alloy and the interdendritic regions are enriched with manganese and nickel by Energy Dispersive X-ray Spectroscopy (EDS).
The corrosion resistance of FeCrNiCoMnx is improved with decreasing manganese contents in both H2SO4 and NaCl solutions. It was also found that the passive film of central zone acts more active than that of columnar zone in H2SO4 due to the segregation level. Moreover, the onset of pitting in NaCl is related to the manganese content of the FeCrNiCoMnx.

References:

[1] A. Gali et al. Tensile properties of high- and medium-entropy alloys. Intermetallics 39 (2013) 74-78.
[2] Y. F. Kao et al. Electrochemical passive properties of AlxCoCrFeNi (x = 0, 0.25, 0.50, 1.00) alloys in sulfuric acids. Corrosion Science 52 (2010) 1026-1034.
[3] H. Luo et al. Corrosion behavior of an equiatomic CoCrFeMnNi high-entropy alloy compared with 304 stainless steel in sulfuric acid solution.
Corrosion Science 134 (2018) 131–139.

Figure 1
Prediction of Pad Wear Depending on Structural Factors of Diamond Conditioner
Authors: Kim Taesung 
Published: February 2020

The conditioning process with diamond conditioners is an important role in maintaining chemical mechanical polishing (CMP) performance constant. The conditioning process maintains the surface roughness of the pad and uniformity of the pad wear, resulting in stable material removal rate (MRR) and low within wafer non-uniformity (WIWNU). The pad uniformity is greatly changed by the mechanical action in the conditioning process, and the action is controlled by three mechanical movements; pad / conditioner rotation, conditioner arm sweep. From these three motions, the pad wear profile can be obtained by accumulating the number of points in the pad mesh containing the coordinates of the diamonds moving at a specific time or distance by the movement of the diamond grit as shown in Fig. 1.
In addition, we tried to confirm the pad profile and wear amount depending on the structural properties of the conditioner, applying the diamond characteristics of the conditioner which directly causes the wear. The structural factors of conditioner that affect conditioning are pattern, pitch, size, number and shape of diamond. These factors were formulated and applied in simulation. Then, pad wear amount was calculated from the indentation depth according to the diamond characteristics, and pad profile by wear rather than profile by line density was proposed. The pad wear amount of simulation results according to the number of diamonds are shown in Fig. 2.
Finally, pad wear can be predictable according to various equipment or process conditions and it is also possible to analyze the effect of the conditioner on pad wear through this research. This work is achieved by approaching the process of conditioning in CMP from the topologic aspects and the program is developed through it. The kinematic motion of individual diamonds is modelized and simulated with structural properties of the conditioner to see how these affects the pad wear and profile.

Figure 1
Electroless Metal Deposition Using Multivalent Metal Ions As Reducing Agents
Authors: Norkus Eugenijus , Tamašauskaitė-Tamašiūnaitė Loreta 
Published: February 2020

The possibility and conditions to use lower oxidation state metal ions as reducing agents for autocatalytic electroless metal deposition are discussed.
The theoretical background of such kind reactions is presented in the view of thermodynamics.
Kinetic data on electroless silver, copper, palladium and platinum deposition using Co(II)/Co(III) redox systems with different ligands are presented and discussed.
Ti(III)/Ti(IV) redox systems with different ligands were shown also to be suitable reducing agents for reducing of Pt(IV), Pd(II), Ni(II) and Co(II) to metallic state and formation of continuous metal layer on the surface to be plated.
The morphology of metal layers deposited using above-mentioned reducing agents was characterized by means of Field Emission Scanning Electron Microscopy (FESEM). Kinetics of metal deposition rate was investigated by means of the gravimetry or Electrochemical Quartz Crystal Microgravimetry (EQCM).
Hybrid Electrodeposition and Characteristics of Ag-Graphene Composite Films on Cu Sheets Toward High-Performance Electric Connectors
Authors: Sakaida Shizuka , Kure-Chu Song-Zhu Shochiku , Hihara Takehiko , Yashiro Hitoshi 
Published: February 2020

Recently, silver (Ag) plating for automotive connector has been attracted extensively attention due to the fast progress of HEV/EV system and as a promising candidate material to substitute the costive gold (Au) plating. The Ag plating film possesses the highest conductivity among the metals and excellent corrosion resistance next to Au plating. However, Ag plating suffers a low wear resistance problem because of the soft nature of Ag metal (~80 Hv). Because an oxidation film is difficult to form on silver surface, the corrosion resistance is good. More serious problem of Ag plating is that an adhesion phenomenon often occurs during sliding wear actions as terminal mating materials, because an oxidation film is difficult to form on Ag surface owing to the good corrosion resistance as a noble metal. To solve those problems, many studies focused on fabricate hard Ag plating by adding some alloy elements like Co, Sb, and Se or adding graphite powder into Ag plating films, which improved wear resistance but sacrificed electric conductivity.
Here, we propose a new Ag-graphene electro-plating film, with the graphene functioning as solid lubricant and electric component, which may reinforce the wear resistance while without lowering its electric conductivity. The Ag-graphene composite films were fabricated on Cu sheets by a hybrid electrodeposition method, i.e., combining electrodeposition of Ag and electrophoric deposition of graphene nano-flakes, in a non-cyanate plating bath. The graphene nano-flakes were prepared by an electrochemical peeling method from a graphite material. The microstructures, chemical composition, and crystalline structure of the anodized specimens before and after annealed were investigated FE-SEM (EDS), XRD, GD-OES, FT-IR, and Raman spectroscopy. Moreover, the electric resistance meter and wear resistance were also investigated, compared to commercial Ag plating as reference.
Figs. 1a and 1b show the surface FE-SEM images of as-electrodeposited pure Ag and Ag-graphene films respectively. It can be seen that, except for the featured Ag nano-particles, some blurry films can be observed on the Ag film in Fig. 1b. The EDS analysis result in Fig.1c demonstrates a strong C peak, indicating the co-deposition of carbon clearly. Moreover, the inclusion of graphene in Ag films were also confirmed by Raman spectra and XRD measurements. The electric resistance of Ag-graphene composite films was equivalent to the commercial Ag films, and the detail results will be reported on the meeting.

Figure 1