bluuebunny/crossref_metadata_2025_split huggingface dataset:
Failure Analysis of Nickel-Coated Anodes in Zinc-Air Hybrid Flow Batteries
Authors: Hu Hang , He Anqiang , Ivey Douglas , Aasen Drew , Arfania Sheida , Shukla Shantanu 
Published: July 2022

A zinc-air flow battery system pumps "fuel” (a zinc particle/KOH slurry) from a fuel tank to a fuel cell stack, where the zinc particles are combined with oxygen from the air to form zincate ions and produce electricity. The zincate-rich electrolyte is then returned to the fuel tank. During the charging cycle, the electrolyte is passed to the zinc regenerator, where electricity (from renewable sources such as solar or wind) is utilized to convert the zincate ions to zinc particles. The regenerated fuel is pumped back into the fuel tank for the discharge process.
Nickel is considered for use as the anode during zinc regeneration as it has been shown to be an active catalyst for the oxygen evolution reaction (OER). However, nickel electrodes pose manufacturing challenges due to machinability issues. Alternatively, nickel can be coated on a machinable metal substrate to improve scalability. These electrodes are subjected to open circuit voltage (OCV), OER, and the hydrogen evolution reaction (HER) during operation of zinc-air flow batteries. The electrodes have been observed to fail during prolonged voltage cycling due to nickel coating delamination, which manifests itself as blistering, flaking, and discoloration. It is hypothesized that this may be due to electrolyte penetration into the pores of the nickel coating during operation. The present work is aimed at analyzing and mitigating the coating delamination process through characterization of various Ni coating recipes. As-fabricated and cycled electrodes are characterized using various microstructural techniques, including optical microscopy, x-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), and x-ray tomography. Coated electrodes are also evaluated electrochemically and the results are correlated with the microstructural analysis. The overall goal of the work is to understand the failure mechanisms and apply the knowledge to fabricate improved coatings for OER electrodes.
(Invited, Digital Presentation) High Quality 2-D Materials Characterized Paradoxically from Broad Diffraction Features
Authors: Tringides Michael C 
Published: July 2022

Paradoxically a very broad diffraction background, named the Bell-Shaped-Component (BSC), has been established as a feature of graphene growth. Recent diffraction studies as a function of electron energy on Gr/SiC have shown that the BSC is not related to scattering interference. The broad background is in-phase with the Bragg component of both the (00) and Gr(10) spots. Instead textbook diffraction states it should be out-of-phase since it should originate from destructive interference between adjacent terraces[1]. Additional experiments were carried out as a function of temperature over the range 1200° C-1300° C that single-layer-graphene (SLG) grows. Quantitative fitting of the profiles shows that the BSC follows the increase of the G(10) spot, proving directly that the BSC indicates high quality graphene[2]. The BSC has been also seen in graphene on metals including Gr/Ir(111) and on h-BN/Ir(111)[3,4]. Its presence in such a wide range of 2-materials suggests its origin must be general and fundamental, related to their unusual single layer uniformity. The BSC can be a diagnostic of high quality in the growth of other 2-d materials. One possible explanation of the BSC relates to electron confinement within a single uniform layer, according to the uncertainty principle, which generates spread in their wavevector as confirmed with ARPES[5]. The transfer of the large momentum spread to the diffracted electrons to generate the BSC requires better theoretical understanding of the graphene electron-beam electron interaction.
Work in collaboration with P. A. Thiel (deceased), S. Chen, E. Conrad, M. Horn von Hoegen, M. Petrovic, F.-J. Meyer zu Heringdorf
[1] S. Chen, et al.
Phys. Rev. B. 100, 155307 (2019).
[2] S. Chen, et al.
J. Phys. Chem. Lett. 11, 8937 (2020).
[3] K. Omambac et al , Appl. Phys. Lett. 118, 241902 (2021)
[4]M. Petrovic et al
Nanotechnology 32 505706 (2021)
[5] T. Ohta et al.
Phys. Rev. Lett. 98, 206802 (2007).
Fundamental Charge Transfer Dynamics in 2D TMDCs for Use in Novel Heterostructures
Authors: Myers Alexis , Blackburn Jeff 
Published: July 2022

Efficient transfer of charge carriers and/or excitons between small organic molecules and two-dimensional (2D) semiconductor interfaces is being explored for applications in photovoltaics and quantum information processing.
Interfaces of small molecules and 2D semiconductors such as graphene, nanocrystals, quantum dots and transition metal dichalcogenides (TMDCs) are capable of charge, energy, and spin singlet transfer. The long excited state lifetimes of spin triplet excitons makes triplet exciton transfer across such interfaces advantageous for exciton harvesting and photon upconversion. However, to date, triplet energy transfer between physisorbed small molecules and monolayer TMDCs has only been reported in a single study. To our knowledge, the process where photoexcitation of a TMDC/organic interface yields triplet excitons in the TMDC layer has not been reported. In quantum dot (QD) systems, direct covalent attachment of organic molecules to QD surfaces has shown to facilitate triplet energy transfer across the QD/molecule interface, but this covalent approach has not been widely applied to TMDC/molecule interfaces.
Here we present a systematic study of covalently functionalized TMDC/molecule interfaces employing synthetically tailored thiolated acenes. We create tunable amounts of sulfur vacancies, which allows for subsequent covalent acene functionalization. We study the impact of covalent bonding on the charge transfer (CT) dynamics of TMDC/organic interfaces with energy level offsets suitable for charge and energy transfer (ET) as well as triplet acceptance and sensitization. We characterize the interfaces with a variety of steady-state and time-resolved spectroscopic techniques and initial results show success in selective isolation of CT vs ET pathways.

Figure 1
Low Temperature WS2 Metal-Organic Chemical Vapor Deposition Using n-Bunc-W(CO)5
for W Precursor
Authors: Cho Kirito , Machida Hideaki , Ishikawa Masato , Sudoh Hiroshi , Wakabayashi Hitoshi , Yokogawa Ryo , Sawamoto Naomi , Ogura Atsushi 
Published: July 2022

Tungsten disulfide (WS2) is one of the representative two-dimensional layered materials, and its applications in various fields have been actively studied due to its preferable properties such as reasonably wide band gap (monolayer: 2.03 eV, bulk: 1.32 eV) [1] and excellent stability. In particular, large area, a few layer WS2 has a high potential as channel material for MOSFET in the next generation LSI. In most of the WS2 CVD reported so far, WF6 or W(CO)6 has been widely used for tungsten precursor as well as H2S for S precursor. However, there are critical problems for the precursors: WF6 is toxic, and W(CO)6 is solid and hard to supply to the reaction chamber. Sublimation supply of solids is not stable in terms of transport volume, and sometime clogging of pipes is also a concern. H2S is also highly toxic.
In this study, a tungsten precursor of n-BuNC-W(CO)5 was investigated for WS2 deposition. One of its favorable characteristics is that it is liquid above 35 °C with stable vapor supply. It is also expected to interact with the substrate efficiently due to its polarity in the molecule. The vapor pressure is 1.2 torr at 115 °C, which is an appropriate for a CVD precursor. As a sulfur precursor, (t-C4H9)2S2 [2], which is non-toxic in contrast to H2S, was employed. WS2 thin films were grown by MOCVD in a cold-wall reactor, using the organic compounds introduced above as precursors for W and S, respectively, on silicon (001) or sapphire (0001) substrates. The deposited films were evaluated by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy (wavelength: 355 nm), and transmission electron microscopy (TEM).
As a result, the continuous films were successfully obtained at the deposition temperature over 250 °C. XPS measurements showed the S/W ratio were slightly larger than the stoichiometric value of two (Fig. 1(a) and (b)). Residual C contamination was significantly reduced by elevating the deposition temperature over 300 °C. The Raman spectra confirmed the film was multi-layer WS2 with peak at 356 cm-1 (E1
2g) and 419 cm-1 (A1g) (Fig. 1(c)). TEM observation also revealed the film had a layered structures as is shown in the typical 2D materials (Fig. 1(d)).
This study was partly supported by JST CREST Number JPMJCR16F4, Japan.

Reference

[1] J. Gusakova, X. Wang, L. L. Shiau, A. Krivosheeva, V. Shaposhnikov, V. Borisenko, V. Gusakov, and B. K. Tay, Phys Status Solidi.
214, 12 (2017).
[2] C. Kirito, K. Yamazaki, Y. Hibino, Y. Hashimoto, H. Machida, M. Ishikawa, H. Sudoh, H. Wakabayashi, R. Yokogawa and A. Ogura, ECS Trans.
104, 3 (2021).

Figure 1
(Invited) Long-Life Sodium-Sulfur Batteries Enabled By a Localized High Concentration Electrolyte
Authors: Bhargav Amruth , He Jiarui , Shin Woochul , Manthiram Arumugam 
Published: July 2022

The high abundance of both sulfur and sodium on earth makes room-temperature sodium-sulfur (Na-S) batteries a low-cost, environmentally benign, sustainable energy storage technology.1 High reactivity and instability of the Na-metal anode and the formation and migration of sodium polysulfides (NaPSs) at the sulfur cathode need to be mitigated to make this technology viable. The root cause of these issues can be the traced to the electrolytes that are conventionally used.
To simultaneously solve the issues mentioned above, we utilize a localized high concentration electrolyte (LHCE).2 LHCE is prepared by diluting a concentrated salt solution with an inert solvent. The resulting unique solvation structure of the electrolyte favors the decomposition of the sodium salt to yield a thin, robust, ion-conducting SEI on both the anode and the cathode. This enables highly efficient and reversible stripping and plating at the Na-metal anode. At the sulfur cathode, this SEI changes the sulfur redox pathway by preventing the formation of NaPSs and steers it towards a quasi-solid-state conversion reaction. These benefits significantly prolong the life of the battery and bring the Na-S technology a step closer to viability.

References

A. Manthiram and X. Yu, Small, 11, 2108–2114 (2015).

J. He, A. Bhargav, W. Shin, and A. Manthiram, J. Am. Chem. Soc., 143, 20241–20248 (2021).

Figure 1
(Invited) Synthesis and Properties of Fluorinated Cubanes
Authors: Akiyama Midori , Sugiyama Masafumi , Komaguchi Kenji , Nozaki Kyoko , Okazoe Takashi 
Published: July 2022

Electron acceptor molecules play an important role in the design of organic functional materials. The electron acceptor molecules reported so far are limited to π-conjugated molecules, which stabilize the accepted electrons by delocalizing them in the extended π-orbitals. In contrast, in perfluorocubane, in which eight carbons of the box-shaped molecule are fluorinated, the eight σ* orbitals of the C-F bonds overlap inside the box and are expected to accept and stabilize electrons there.[1] Since perfluorocubane is expected to accept electrons by overlapping σ* orbitals, it will probably show different physical properties from those of π-conjugated electron acceptor molecules.
In the present study, we have succeeded in introducing multiple fluorine atoms into the carbon of cubane derivatives by using an original synthetic technique using fluorine gas,[2] which cannot be used in conventional synthetic organic chemistry. Using this key reaction, perfluorocubane (1), heptafluorocubane (2), and hexafluorocubane (3) were synthesized. Electrochemical and spectroscopic measurements demonstrated that the electron affinity increased with increasing the number of fluorine atoms. Furthermore, the successful observation of perfluorocubane radical anion by ESR measurement will be reported.
[1] Irikura, K. K. J. Phys. Chem. A
2008, 112, 983–988. [2] Okazoe, T. J. Fluorine Chem.
2015, 174, 120–131.

Figure 1
(Invited, Digital Presentation) Synthesis, Aromaticity and Application to OFET and OLED of Peri-Pentacenopentacene
Authors: Mamada Masashi , Jousselin-Oba Tanguy , Wright Karen , Marrot Jérome , Adachi Chihaya , Yassar Abderrahim , Frigoli Michel 
Published: July 2022

Recently, there has been increasing interest in a class of polycyclic aromatic hydrocarbons (PAHs) with peri-extension of acenes. These peri-fused systems, referred to as peri-acenes and acenoacenes, are considered to be nanographenes.[1–3] Thus, the compounds based on tetracene and larger acenes show singlet biradical nature at the zigzag edge, offering unique and interesting properties.
However, the synthesis schemes for these compounds are generally complicated, which hinder the extensive development of these derivatives and application to organic optoelectronics such as organic field-effect transistors (OFETs) and organic light-emitting diodes (OLEDs). A pentacene derivative with two triisopropylsilylethynyl groups at the central ring (TIPS-PEN) was developed in 2001. It shows good solubility, stability, and semiconducting property, resulting in being one of the most studied organic semiconductors. In contrast, the peri-extended compound of TIPS-PEN has not been developed because of the difficulty in synthesis using the same method as TIPS-PEN.[4] Here, we found the synthetic conditions to avoid the competition between 1,2- and 1,4-addition of lithium acetylide on large aromatic dione and succeeded in synthesizing TIPS-ethynyl-substituted peri-pentacenopentacene (TIPS-PPP).[5]
The stability of TIPS-PPP was 16 times superior to that of TIPS-PEN, which is attributed to higher aromaticity as shown in an electronic structure of two-fused anthracene. TIPS-PPP shows the crystal packing of the 2D-brickwall motif like TIPS-PEN. The high mobility of up to 1 cm2 V−1 s−1 was obtained in OFET fabricated by wet process owing to large transfer integrals and low reorganization energies. In addition, TIPS-PPP showed high quantum yield in near-infrared (NIR) region. Thus, it was used as an emitter for NIR-OLED devices, resulting in high external quantum efficiency at 800 nm. These results suggest that acene-like materials are very promising for developing NIR emitters.
References
[1] M. Mamada, R. Nakamura, C. Adachi, Chem. Sci.
2021, 12, 552.
DOI: 10.1039/D0SC04699J
[2] T. Jousselin-Oba, M. Mamada, J. Marrot, A. Maignan, C. Adachi, A. Yassar, M. Frigoli, J. Am. Chem. Soc.
2019, 141, 9373.
DOI: 10.1021/jacs.9b03488
[3] Y. Gu, Y. G. Tullimilli, J. Feng, H. Phan, W. Zeng, J. Wu, Chem. Commun.
2019, 55, 5567.
DOI: 10.1039/c9cc01986c
[4] X. Zhang, J. Li, H. Qu, C. Chi, J. Wu, Org. Lett.
2010, 12, 3946.
DOI: 10.1021/ol101720e
[5] T. Jousselin-Oba, M. Mamada, K. Wright, J. Marrot, C. Adachi, A. Yassar, M. Frigoli, Angew. Chem. Int. Ed.
2021,
DOI: 10.1002/anie.202112794.
(Invited) Metalation Effect on Diketopyrrolopyrrole-Tetrabenzoporphyrin Conjugate As p-Type Material in BHJ Organic Photovoltaics
Authors: Vats Ajendra Kumar , Matsuo Kyohei , Yamada Hiroko 
Published: July 2022

Organic photovoltaics have attracted much attention for the next generation of photovoltaics. Tetrabenzoporphyrin (BP) is a p-type organic semiconductor characterized as the large, rigid p-framework, excellent stability, and good photoabsorption capability. Because of the low solubility, thermal precursor approach is necessary for the deposition of BP by solution process, where a soluble precursor (CP) of BP is spin-coated on the substrate, followed by annealing of CP film to make BP film by in-situ retro-Diels-Alder reaction of CP.[1,2] In 2017, we reported side-chain engineering for efficient photocurrent generation using a series of diketopyrrolopyrrole (DPP)–tetrabenzoporphyrin (BP) conjugates named Cn-DPP–BP (n = 4, 6, 8 or 10 depending on the length of n-alkyl groups on the DPP unit) as p-type materials in BHJ OPVs in combination with PC61BM as a n-type material by the thermal precursor approach.[3] The comparative study shows that the short-circuit current density largely depends on the length of alkyl substituents, ranging from 0.88 mA cm-2 with C10-DPP–BP to 15.2 mA cm-2 with C4-DPP–BP. C10-DPP–BP in the film is edge-on orientation dominant while that of C4-DPP–BP is face-on orientation dominant.
Encouraged with the results, we synthesized a zinc complex of C4-DPP-CP (C4-DPP-ZnCP) as a soluble precursor of C4-DPP-ZnBP to investigate the effect of metalation of the porphyrin cavity for the BHJ OPV performance. BHJ OPV was prepared by thermal precursor approach: spin-coating of a mixed solution of the precursor, C4-DPP-ZnCP, and PC61BM, followed by annealing at 200 ºC to make a blend film of C4-DPP-ZnBP and PC61BM. Interestingly, the energy gap and ionization potential of C4-DPP-ZnBP film and C4-DPP-BP film are similar to each other, but the Jsc of C4-DPP-ZnBP is 1.5 times larger than that of C4-DPP-BP. We will discuss the relationship between film morphology and OPV performance by studying the blend film of C4-DPP-ZnBP/PC61BM by atomic force microscopy (AFM), X-ray diffraction (XRD) analysis and p-polarized multiple-angle incidence resolution spectrometry (p-MAIRS).
References

H. Yamada, T. Okujima, N. Ono, Chem. Commun. 2008, 2957-2974.

H. Yamada, D. Kuzuhara, M. Suzuki, H. Hayashi, N. Aratani, Bull. Chem. Soc. Jpn.
2020, 93, 1234-1267.

K. Takahashi, D. Kumagai, N. Yamada, D. Kuzuhara, Y. Yamaguchi, N. Aratani, T. Koganezawa, S. Koshika, N. Yoshimoto, S. Masuo, M. Suzuki, K. Nakayama, H. Yamada, J. Mater. Chem. A
2017, 5, 14003-14011.
(Invited) Structural Analysis of Organic Semiconducting Materials By Solid State NMR
Authors: Suzuki Katsuaki , Kaji Hironori 
Published: July 2022

Recently, our group have successfully developed several blue and green thermally activated delayed fluorescence (TADF) emitters showing high external quantum efficiencies in OLEDs through high-throughput screening based on quantum chemical calculations. Although a number of highly efficient TADF emitters have been reported, the study about their conformation and aggregated structure in an amorphous states, which is expected to be the origin of high device performance, is still limited. Thus we have carried out multiscale simulations and solid-state NMR (ssNMR) analysis of organic amorphous thin films. The ssNMR is one of the powerful technique to acquire the structural information of amorphous aggregated materials, which has been difficult by diffraction techniques due to the lack of long range order for amorphous state. In this presentation, we demonstrate ssNMR analysis of amorphous organic semiconducting materials.
Reference
(1) “Analysis of Molecular Orientation in Organic Semiconducting Thin Films Using Static Dynamic Nuclear Polarization Enhanced Solid-State NMR Spectroscopy”, Suzuki, K.; Kubo, S.; Aussenac, F.; Engelke, F.; Fukushima, T.; Kaji, H. Angew. Chem. Int. Ed. 2017, 56, 14842.
(2) “Efficient blue thermally activated delayed fluorescence emitters showing very fast reverse intersystem crossing”, Ren, Y., Wada, Y., Suzuki, K., Kusakabe, Y., Geldsetzer, J. and Kaji, H.

Appl. Phys. Express, 2021, 14, 071003.
(3) “Solution-processable thermally activated delayed fluorescence emitters for application in organic light emitting diodes”, Suzuki, K.; Adachi, C.; Kaji, H. J. Soc. Inf. Disp.
2017, 25, 480.
(4) “Combined Inter- and Intramolecular Charge-Transfer Processes for Highly Efficient Fluorescent Organic Light-Emitting Diodes with Reduced Triplet Exciton Quenching”, Moon, C.-K.; Suzuki, K.; Shizu, K.; Adachi, C.; Kaji, H.; Kim, J.-J. Adv. Mater.
2017, 131, 6614.
(5) “Triarylboron-based Fluorescent Organic Light-emitting Diodes with External Quantum Efficiencies Exceeding 20%”, Suzuki, K.; Kubo, S.; Shizu, K.; Fukushima, T.; Wakamiya, A.; Murata, Y.; Adachi, C.; Kaji, H.; Angew. Chem. Int. Ed. 2015, 54, 15231.
(5) “Purely organic electroluminescent material realizing 100% conversion from electricity to light”, Kaji, H.; Suzuki, H.; Fukushima, T.; Shizu, K.; Suzuki, K.; Kubo, S.; Komino, T.; Oiwa, H.; Suzuki, F.; Wakamiya, A.; Murata, Y.; Adachi, C. Nat. Commun. 2015, 6, 8476.
(Invited) Functional Materials and Sustainable Process for Commercialization of Perovskite Solar Cells
Authors: Jung Hyun Suk 
Published: July 2022

All solid-state solar cells based on organometal trihalide perovskite absorbers have already achieved distinguished power conversion efficiency (PCE) to over 25% and further improvements are expected up to 27%. Now, the research on perovskite solar cells (PSCs) has been moving toward commercialization. To facilitate commercialization of these great solar cells, some technical issues such as long-term stability, large scale fabrication process, and Pb-related hazardous materials need to be solved. Also, flexible perovskite solar cell using plastic substrate can be used in niche applications such as portable electrical chargers, electronic textiles, and large-scale industrial roofing.
This talk is dealing with our recent efforts to facilitate commercialization of perovskite solar cells. For examples, we introduce a recycling technology of perovskite solar cells, which covers the regeneration process of Pb contained perovskite layer as well as recycling process of Au electrodes and transparent conducting oxide glass. Also, simple fabrication technologies for realizing large scale perovskite module are introduced and recent effort for achieving high efficiency module is going to be presented. Precursor technology is of great importance for yielding high efficiency and reproducibility of PSC, which is one of topics in this talk.
(Invited, Digital Presentation) Transformations of Ionic Nanocrystals Via Ion Exchange Reactions
Authors: Teranishi Toshiharu 
Published: July 2022

Elaborate chemical synthesis methods allow the production of various types of inorganic nanocrystals (NCs) with uniform shape and size distributions. Then, how can we synthesize NCs with thermodynamically metastable phases or very complex structures? The transformation of already-synthesized NCs via elemental substitutions, such as ion exchange reactions for ionic NCs [1,2] and galvanic replacement reactions for metal NCs [3], can overcome the difficulties facing conventional one-step syntheses. In particular, NC ion exchange reactions have been studied with numerous combinations of foreign ions and ionic NCs with various shapes. The functionality of the resulting ionic NCs, including semiconducting and plasmonic properties, can be easily tuned in a wide range, from the visible to near-infrared. Here we focus on the full and partial ion exchange reactions involving ionic NCs, highlighting important aspects such as the preservation of appearance and dimensions [4,5]. Finally, visible-to-near infrared light energy conversion systems using partially exchanged ionic NCs are provided [6,7].
[1] Saruyama, M.; Sato, R.; Teranishi, T. Acc. Chem. Res.
2021, 54, 765.
[2]Saruyama, M.; Teranishi, T. et al., J. Am. Chem. Soc.
2011, 133, 17598.
[3] Sato, R.; Teranishi, T. et al., to be submitted.
[4] Wu, H.-L.; Teranishi, T. et al., Science
2016, 351, 1306.
[5] Li, Z.; Saruyama, M.; Asaka, T.; Tatetsu, Y.; Teranishi, T. Science
2021, 373, 332.
[6] Lian, Z.; Teranishi, T. et al., Nat. Commun.
2018, 9, 2314.
[7] Lian, Z.; Teranishi, T. et al., J. Am. Chem. Soc.
2019, 141, 2446.