bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Digital Presentation) Nanoscale Sculpturing of Al and Al Alloys for Heterogeneous Al-Cu Joints
Authors: Baytekin Gerngross Melike , Gerngross Mark Daniel , Carstensen Juergen , Adelung Rainer 
Published: December 2024

Heterogeneous Al-Cu joints are nowadays generated in a huge variety of different techniques depending on the intended application, such as corrosion protection of Al components, electric connections with improved interfaces, or even lightweight current collectors for batteries.
Four major techniques are commonly used that can be further subdivided into cladding (including roll cladding, thermo-compression bonding, friction welding etc.), vapor deposition (including PVD, CVD etc.), thermal spraying and chemical plating (including electroless and electrochemical plating). Each of the methods offers certain advantages and disadvantages for the formation of Al-Cu joints. Typically observed disadvantages are the formation of intermetallic Al-Cu compounds (IMC), higher electric resistivity, a rather low mechanical strength under static or cyclic mechanical load conditions.
The present work follows the electrochemical route to form Al-Cu joints utilizing nanoscale sculpturing of the Al substrate [1] as a starting point to overcome these above described typically observed disadvantages of Al-Cu joints. The resulting nanoscale sculptured Al-Cu joint is intensively characterized with respect to its structural (see Fig. 1), chemical and mechanical properties. It was found that such Al-Cu joints offer a high mechanical load bearing capability because of the interlocking zone between Al and Cu offering a gradual change, so that an optimum stress transfer can occur without the risk of a stress pile-up at the interface between both metals.
Furthermore, no intermetallic Al-Cu phases grow at the interface between Al and Cu during deposition which could mechanically weaken the joint due to embrittlement, especially under cyclic loading conditions. Another advantage is the absence of Al-Cu intermetallics in the joint, being of great importance if high current or high voltage applications are intended.
Fig 1: Nanoscale sculptured Al surface with cubic interlocking surface structures in cross-section (left) and cross-sectional view on Al-Cu joint after electrochemical Cu deposition on nanoscale sculptured Al surface (right).
[1] M. Baytekin-Gerngross, M.D. Gerngross, J. Carstensen, and R. Adelung, Nanoscale Horizon 1(6), 467 (2016).

Figure 1
(Invited) One Dimensional Anodic TiO2 Nanotubes for Energy and Catalytic Applications
Authors: Sopha Hanna , Sepúlveda Sepúlveda Lina Marcela , Macak Jan M. 
Published: December 2024

Self-organized TiO2 nanotube (TNT) layers, prepared by anodization of Ti have in suitable electrolytes, attracted considerable scientific and technological interest, especially due to their wide range of applications including (photo-) catalysis, hydrogen generation and biomedical uses [1,2].
The advantages of anodic TNT layers compared to TiO2 nanotubes prepared by other methods (e.g. hydrothermal) are the tunability of dimensions, their directionality, the ability to absorb significant amount of incident light, and the possibility to utilize nanotube interiors and exteriors for decoration or coating with secondary materials [2].
The presentation will review the recent advancements in TNT layer synthesis for their use for the photocatalytic degradation of pollutants in the liquid and in the gas phase. This will include the upscaling of TNT layers from the laboratory scale to several dozens of cm2 [3-6], with a strong focus on the anodization of 3D Ti substrates by bipolar electrochemistry, which cannot be directly connected to the potentiostat (such as Ti meshes) [5-6]. The application of these large scale TiO2 nanotube layers in flow-through photocatalytic reactors will be discussed [3-6]. Additionally, the selective etching of double wall TiO2 nanotube layers towards single wall TiO2 nanotube layers [7] and single nanotube powders [8, 9] will be presented, showing the possibility of preparing magnetically guidable single nanotube photocatalysts by a decoration with Fe3O4.
The presentation will also summarize recent advancements in the utilization of TNT layers in energy conversion and energy storage applications [10], in particular Li-ion microbatteries. Experimental details and photocatalytic and battery results will be presented and discussed.
References
[1] J.M. Macak et al., Curr. Opin. Solid State Mater., 11 (2007) 3.
[2] F. Dvorak et al., Appl. Mater. Today 14 (2019) 1-20.
[3] H. Sopha et al., Electrochem. Commun. 111 (2020) 106669.
[4] H. Sopha et al., Appl. Mater. Today, 29 (2022) 101567.
[5] H. Sopha, et al., Nano Lett. 21 (2021) 8701.
[6] H. Sopha, et al., Nano Lett. 23 (2023) 6406.
[7] M. Motola et al., Electrochem. Commun., 97 (2018) 97.
[8] D. Beketova et al., ACS Appl. Nano Mater. 3 (2020) 1553.
[9] M. Sepúlveda et al., Ceram. Int., 49 (2023) 6764.
[10] V. Galstyan, J.M. Macak, T. Djenizian, Appl. Mater. Today 29 (2022) 10161.
(Invited) Atmospheric Corrosion of Multi-Materials on Winter Road Condition in Cold Region
Authors: Fushimi Koji , Nomura Kosaku , Sakairi Masatoshi 
Published: December 2024

The use of multi-materials such as composites of carbon fiber reinforced thermoplastic (CFRTP) and high-strength steel or CFRTP and aluminum alloy is one of the main strategies for weight reduction in automotive body. When multi-materials are used outdoors, however, they are subject to galvanic corrosion, which increases the risk of failure and shortens their service life. On winter roads in cold regions, automotive bodies suffer significant corrosion due to the large amount of salt particles sprayed as an anti-freeze agent. If the corrosion products of the multi-material are relatively protective, the progression of corrosion can be prevented. Therefore, wet-and-dry cycle test was conducted on a coated multi-material joint consisting of CFRTP/high-strength steel or CFRTP/aluminum alloy plates to simulate winter road conditions in Northern Europe, and corrosion products formed in the crevice of multi-materials joint were investigated using a membrane potential measurement as well as Raman spectroscopy and X-ray fluorescence microscopy.
The wet-and-dry cycle test, in which a sample was immersed in a 5:1 mixture of NaCl and CaCl2 solutions for 0.25 h and then repeatedly subjected to a wet atmosphere of 90%RH, 283 K for 4 h and a dry atmosphere of 10%RH, 308 K for 4 h more than a dozen times, was performed according to Kozaki [1]. After several weeks or more of exposure under the wet-and-dry cycle test conditions, corrosion products filled the crevice of the multi-material sample and did not to allow air leakage through the crevice gap. Ion selectivity of the corrosion products in the crevice obtained by the membrane potential measurement was found to be anionic rather than cationic selective in all tests. The products formed in the test using dilute mixture solution were relatively porous hydroxides and oxides and showed larger fixed charge concentrations than those formed in the test using concentrated solution. It was suggested that the density and composition of corrosion products play important roles in preventing atmospheric, galvanic corrosion in the gap of CFRTP/high-strength steel or CFRTP/aluminum alloy joints.
[1] T. Kozaki, M. Umeta, J. Surf. Finish. Soc. Jpn.
73 (2022) 384-389.
Visualization of Hydrogen Absorbed into High Strength Steel during Corrosion Process By Mn Oxide Thin Film
Authors: Sugawara Yu , Omoda Masataka , Ootsuka Shinji 
Published: December 2024

Hydrogen embrittlement is a serious problem for high strength steels because the susceptibility increases with the strength of steels. Reducing hydrogen absorption into steels is required for the prevention of hydrogen embrittlement. It is well-known that one of the hydrogen absorption processes for steels is atmospheric corrosion. In general, atmospheric corrosion causes a rough and non-uniform surface, thus hydrogen absorption into steels during the corrosion process is thought to have an uneven distribution. To observe the distribution of hydrogen absorption into steels, we reported a method for hydrogen mapping using a WO3 thin film1,2). As hydrogen enters, the WO3 film formed on the hydrogen-detection side changes color by the reaction from WO3 to HxWO3. In this study, the hydrogen mapping method was improved and became more responsive and visible using Mn oxide instead of WO3. In addition, we succeeded in visualizing the distribution of hydrogen absorption into the high strength steel during the corrosion process in 0.01 M NaCl using the hydrogen mapping method with Mn oxide. The hydrogen mapping test shows that the areas where the color of Mn oxide changed corresponded to the areas where corrosion products were deposited on the hydrogen-entry side. This result suggests that hydrogen absorption into the steel occurred at the corroded areas and did not occur preferentially at the cathodic reaction site.
1) Y. Sugawara, Y. Sakaizawa, A. Shibata, I. Muto, N. Hara, ISIJ Int., 58, 1860 (2018).
2) Y. Sugawara, H. Saito, ISIJ Int., 61, 1201 (2021).
Atmospheric Corrosion of Aluminum and Aluminum/Gold Thin Films
Authors: Stavila Vitalie , Sin-Yiu Carly , Heo Tae Wook , Merrill Laura C , Sugar Josh D , Melia Michael Anthony , Khan Ryan Muhammad , DelRio Frank William , Wood Brandon C. , Noell Philip James , Allendorf Mark D. 
Published: December 2024

Aluminum and its alloys are extensively utilized in various applications due to their high thermal and electrical conductivity and inherent resistance to corrosion, primarily due to the formation of a protective oxide layer. However, the strength, durability and electrical properties of many aluminum-based materials and aluminum/gold contacts tend to diminish in humid environments. Therefore, a thorough understanding of the mechanistic aspects of atmospheric corrosion reactions over time in pure Al and galvanic Al/Au couples is crucial for predicting degradation and optimizing performance. Presently, much of our knowledge regarding atmospheric aluminum corrosion is derived from empirical correlations based on extensive corrosion data, typically involving a simplistic relationship between corrosion rates and environmental factors. However, the mechanistic understanding of corrosion processes, particularly during in the presence of electrolytes like sodium chloride found in the environment is not fully elucidated.
Here we propose a new surface approach to obtain mechanistic insights into atmospheric corrosion of Al and Al/Au thin films in the presence of NaCl. The corrosion rate is investigated through a combination of experimental and theoretical approaches, correlating corrosion kinetics with electrolyte chemistry, mass changes, and corrosion byproducts. Quartz crystal microbalance with dissipation (QCM-D) electrodes coated with aluminum and aluminum/gold contacts and sodium chloride serve as the experimental platform. The structure, composition, and surface morphology of the samples are analyzed using various techniques including grazing-incidence X-ray diffraction, FTIR spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, transmission electron microscopy, and electron energy loss spectroscopy.

Operando data with nanogram resolution provided by the QCM-D technique allows real-time monitoring of corrosion product formation, facilitating the derivation of rate constants for corrosion surface reactions. It is observed that the reaction rate in dry air is negligible, but a significant acceleration occurs at relative air humidity levels of 50% and above. Additionally, this study delves into the impact of sodium chloride on the corrosion rate and reaction products, the influence of surface termination on aluminum oxide/hydroxide formation, and the temperature-dependent acceleration of electrochemical corrosion rates. Finally, by integrating theoretical insights with experimental findings, preliminary understanding of the rate-limiting steps has been achieved, paving the way for the development of validated computational models to simulate early-stage atmospheric corrosion processes.
Revealing Failure Mechanisms in Zinc-Manganese Dioxide Batteries Via Nondestructive Electrochemical Diagnostics
Authors: Engmann Eugene , Atifi Abderrahman 
Published: December 2024

The world of long-term-high-density energy storage systems is dominated by the lithium-ion (Li-ion) battery. However, associated setbacks with the Li ion industry such as safety, geopolitical concerns, and rising costs have spearheaded research into investigating alternative approaches to the Li-ion batteries. A promising alternative to the Li-ion battery is the zinc manganese oxide (Zn||MnO2) battery due to its high energy density and much safer chemistry. However, a step towards commercialization of the Zn||MnO2 requires a deep dive into the failure mechanisms native to such cells. These failure mechanisms are identified as electrolyte degradation, increased cell impedance, loss of Zn inventory, and loss of cathode inventory.
Conventionally, techniques employed in identifying failure mechanisms are destructive and time consuming. Thus, there is the need to investigate reliable nondestructive techniques which can predict failure mechanism in Zn|MnO2 cells. In this research an electrochemical approach is pursued, employing the use of cell features such as rest potentials and columbic efficiencies to model various failure mechanisms in Zn||EMD cells. Prior to investigating failure mechanisms, optimization of the Zn||EMD cell is explored based on particle size, EMD weight composition, and electrolyte volume to minimize Mn2+ dissolution.
Carbon-Based Perovskite Solar Cells: Interface Engineering of 5-AVAI Additive
Authors: Perrin Lara , Ito Seigo , Tsuji Ryuki , Flandin Lionel , Planes Emilie 
Published: December 2024

Perovskite materials have great potential for high efficiencies in photovoltaic devices, with the best performances exceeding 26% in a single junction. We now need to further develop perovskite device architectures that combine ease of industrial development with effective durability. Among the alternatives, mesoporous frameworks based on metal oxide and carbon are promising due to their inherent high stability. In the presented work, two perovskite formulations will be compared: MAPbI3 and (5-AVA)xMA1-xPbI3. Both were infiltrated using drop casting as a final step, which provides a clean industrial process for large scale and stable perovskite devices. The aim was to highlight the differences in behavior between devices based on the traditional MAPbI3 perovskite when fabricated with or without 5-ammonium valeric acid iodide (5-AVAI) as an additive. A detailed study with a large series of characterizations (macroscopic functional properties, LBIC imaging, photoluminescence, UV-visible spectroscopy, X-ray diffraction, impedance spectroscopy) has provided new insights into how carbon-based mesoscopic perovskite solar cells perform and degrade.
Perovskites based on AVAI possess higher performances and durability than the original perovskite formulation, however they also demonstrated a higher potential for species diffusion and interface contamination. A special attention will be thus given to the method used to measure performances by analyzing J-V curves at different scan rates. Indeed, this allowed us to define boundary conditions allowing the observation of two different states within our devices (defined as ‘stable’ and ‘metastable’). This behavior was interpreted as a structural transition [1] and can vary according to the perovskite formulation. In addition, the degradation of performance with aging time under damp-heat conditions was found related to a different mechanism in devices formulated with or without AVAI: the critical damage occurring either at the perovskite interfaces or within the perovskite itself.
References:
[1] De Moor, G.; Charvin, N.; Farha, C.; Meyer, T.; Perrin, L.; Planes, E.; Flandin, L. Understanding the Anomalous J–V Curves in Carbon-Based Perovskite Solar Cells as a Structural Transition Induced by Ion Diffusion. Solar RRL
2024, 2300998.
Four-Terminal Double-Junction Solar Cells Consisting of a Mesoscopic Wide-Bandgap Perovskite Solar Cell and an Inverted Narrow-Bandgap Perovskite Solar Cell with Spectral Splitting System
Authors: Ito Kei , Nonomura Kazuteru , Kan Ryota , Tada Keishi , Lin Ching Chang , Kinoshita Takumi , Bessho Takeru , Uchida Satoshi , Segawa Hiroshi 
Published: December 2024

The spectral splitting system is one of the hybridization method to convine different solar cells to improve energy conversion efficiency by dividing sunlight into different spectral ranges. This technique is particularly valuable because different materials exhibit distinct spectral responses. By employing multiple types of solar cells optimized for different parts of the solar spectrum, overall panel efficiency can be increased compared to using a single type of solar cell. Implementing this technique requires careful design and engineering to ensure efficient spectral splitting and maximize electricity output from each type of solar cell. The organometal halide perovskite solar cell (PSC) exhibits a wide range of adjustable band gaps depending on its composition. To attain high efficiency in two-junction PSCs, combination of "mesoscopic" Pb-PSC with an "inverted" Sn-Pb mixed PSC is useful approach. In this study, a four-terminal spectral splitting double junction solar cell was fabricated by combining a mesoscopic-structure Pb-PSC and an inverted-structure Sn-Pb PSC, employing a dichroic mirror to split incident light into long and short wavelengths.
In the experimental setup for the wide-bandgap top cell, initial steps involved the fabrication of compact and mesoscopic structure tin oxide layers on an FTO substrate. Subsequently, several wide-bandgap perovskite absorbers were spin-coated. Then, Spiro-OMeTAD was spin-coated onto the absorber layer, followed by thermal evaporation of gold. For the fabrication of the narrow-bandgap inverted PSC, a layer of PEDOT:PSS was spin-coated onto the FTO substrate. Then several narrow-bandgap perovskite absorbers were spin-coated. Finally, fullerene, bathocuproine, and silver were thermally evaporated onto the substrate. Finally, a four-terminal spectral splitting tandem solar cell was fabricated by combining the wide-bandgap mesoscopic structure top cell and the narrow-bandgap inverted structure bottom cell.
J-V measurements conducted at several split wavelengths revealed a photovoltaic conversion efficiency (PCE) of over 20% for the top cell and about 5% for the bottom cell was obtained. However, the result showed that there is still room for improvement in bottom cell performance. As a result, the bandgap of narrow-bandgap perovskite was reduced by adjusting the ratio of tin and lead such as Cs0.025FA0.475MA0.5Sn0.6Pb0.4I3. This adjustment extended the optical absorption region of bottom cell to slightly longer wavelengths, as measured by EQE. Subsequently, the J-V measurements revealed a photovoltaic conversion efficiency of 20.1 % for the top cell and 5.36 % for the bottom cell at the 801 nm split. The total PCE of 25.5 % was obtained, surpassing previous results.
Improvement of Performance of Perovskite Solar Cell By in-Plane Design
Authors: Yoshihara Yuka , Tada Keishi , Nakazaki Jotaro , Awai Fumiyasu , Nonomura Kazuteru , Uchida Satoshi , Segawa Hiroshi 
Published: December 2024

Perovskite solar cells (PSCs) have attracted attention as one of the next-generation solar cell. To enhance power conversion efficiency (PCE) of PSCs, a great deal of research has been conducted so far, mainly in the field of material development. However, in-plane cell design for evaluating the performance of PSCs are currently not standardized. In this study, optimization of device structures was investigated for the aim of to minimize charge transfer losses and improve FF and PCE.
The fabrication of perovskite solar cell is as follows; (i) as the electron transport layer (ETL), compact TiO2 and mesoporous TiO2 were deposited on FTO glass substrates by spray coating and spin-coating. (ii) K0.025(Cs0.1FA0.9)0.975PbI3 perovskite was deposited by spin-coating using the anti-solvent method1). (iii) Spiro-OMeTAD was spin-coated as the hole transport layer. (iv) The electrodes were insulated by laser etching. (v) Finally, Au was vacuum-deposited and laser-etched again to fabricate the cell.
Throughout the two laser etching stages in the cell fabrication process, adjustments are made to the shapes of the ETL/perovskite layer/HTL and the Au electrode. Specifically, performance was compared for three patterns of devices; (a) round-shaped generator section and current-collecting bridge, (b) shorter distance of current-collecting bridge, (c) shorter distance of current-collecting bridge and same width of current-collecting bridge as generator section. Photoelectric conversion characteristics was determined based on I-V characteristics measured under quasi-sunlight (AM 1.5, 100 mW/cm2) irradiation. In all cases, the shading mask area was kept constant at 0.18 cm2.
Figure shows images of three patterns of the results of comparing FF from I-V measurements for each device with varying shapes. It can be seen that even PSCs fabricated from the same material exhibit different FF values depending on the cell shapes. PCE and FF were higher in (b) than in (a), with the highest values observed for devices of (c), in which the collector bridge is shortened and the width is increased. In addition, the series resistance (Rs) and shunt resistance (Rsh) were approximated from the slope of the I-V curve. Among the internal resistances, the series resistance (Rs) decreased, leading to an improvement in FF. This is thought to be due to the decrease of series resistance of electron and hole transfer.

Figure 1
Ultrathin ALD SnOx Layer for the Interfacial Engineering of Co-Evaporated Sb2Se3 Solar Cells
Authors: Hoang Van-Quy , Lee Jaebaek , Jeon Dong-Hwan , Yang Kee-Jeong , Kang Jin-Kyu , Kadiri-English Bashiru , Sung Shi-Joon , Kim Dae-Hwan 
Published: December 2024

Antimony selenide (Sb2Se3) is a promising photoactive material for low-cost, high-efficiency thin film solar cells due to its non-toxicity, earth-abundance, and unique quasi-1D crystal structure. In this study, we developed a simple co-evaporation technique for antimony chalcogenide on heated substrates at approximately 315 °C under vacuum conditions, which enabled the fabrication of highly pure Sb2Se3 light absorber layers. Additionally, we employed ultrathin SnOx layer prepared by atomic layer deposition (ALD) process as an interfacial engineering layer. The ultrathin ALD SnOx layer acts as a barrier, preventing direct contact between the Sb2Se3 absorber layer and the ammonium cation during the wet chemical deposition process of a CdS buffer layer. Our results demonstrate that the ultrathin ALD SnOx layer reduces recombination at the Sb2Se3/CdS interface. Through a comprehensive comparison involving solar cells with and without the ultrathin ALD SnOx layer, and with systematically varied Sb2Se3 thicknesses, we elucidate the underlying physical explanation of the interfacial engineering of Sb2Se3 solar cells by the ultrathin ALD SnOx layer. Owing to the interfacial engineering by the ultrathin ALD SnOx layer, the Sb2Se3 solar cells incorporating ALD SnOx achieved a power conversion efficiency (PCE) of 6.24%, which is considerably higher value compared with the reference Sb2Se3 solar cells without the ALD SnOx layer.
Acknowledgments
This research was financially supported by the Ministry of Trade, Industry and Energy (MOTIE) and Korea Institute for Advancement of Technology (KIAT) through the International Cooperative R&D program (Project No. P0024567) and by the DGIST R&D program of the Ministry of Science and ICT (24-ET-01).