bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Single-Molecule Electroluminescence Triggered by Field-Driven Tunneling Electrons
Authors: Kimura Kensuke , Imada Hiroshi , Katayama Ikufumi , Takeda Jun , Kim Yousoo 
Published: August 2024

Exciton dynamics governs versatile functions of molecules such as photon emission, photovoltaic and photo chemical reactions. For clarifying the dynamics of excitons in a molecule, an optical measurement with high spatiotemporal resolution is required because the excitons have short lifetimes and their behavior in the local region is important for optical properties. Luminescence spectroscopy based on a scanning tunneling microscope (STM) enable to investigate optical properties with sub-nanometer spatial resolution[1-2]. In this method, scanning tunneling luminescence (STL) spectroscopy, a molecule is excited by the tunneling current of an STM, which can be controlled with atomic spatial resolution. In contrast, the time resolution of STL spectroscopy is limited, because the tunnel current is controlled by electrical circuits. Therefore, this method cannot be used to track the picosecond dynamics of excitons. For overcoming the time-resolution of STL, we have combined a single-cycle terahertz (THz) pulse with STL spectroscopy. By coupling the THz pulse to a tip of an STM, the photoelectric field of THz pulse with sub picosecond time width is confined to the tip apex, which enables to manipulate the tunneling electrons with high spatiotemporal resolutions[4-9]. In this work, we succeeded in forming an exciton in a single molecule by using THz-field-driven current and clarifying the mechanism of the exciton formation.
Single-cycle THz pulses were generated by using optical rectification of near infrared (NIR) laser pulses from a Yb fiber laser using a tilted-pulse-front configuration (Fig. 1a). The generated THz pulses were guided into the STM chamber and focused by using a lens near the tip. We prepared a clean Ag(111) surface and deposited NaCl films. Then, we deposited Pd phthalocyanine (PdPc) molecules on the NaCl/Ag(111) surface. Figure 1b shows THz-STL spectra of a PdPc on NaCl/Ag(111). Several sharp peaks appeared at around 1.9 eV in the red spectrum (with THz irradiation) and no peak appeared in the gray spectrum (without THz). The peak energy of the main peak is identical to the fluorescence peak of a PdPc measured by conventional STL[3], thus we concluded that the singlet excited state was formed by THz-field-driven tunneling. In this presentation, we would like to discuss the detailed mechanism for the exciton formation in a molecule by THz-field-driven electrons.
[1] H. Imada et al., Nature 538, 364 (2016). [2] K. Kimura et al., Nature 570, 210 (2019). [3] S. Cao et al., Nat. Chem. 13, 766 (2021). [4] T. L. Cocker et al., Nat. Photon. 7, 620 (2013). [5] K. Yoshioka et al., Nat. Photon. 10, 762 (2016). [6] V. Jelic et al., Nature Physics 13, 591 (2017). [7] D. Peller et al., Nature 585, 58 (2020). [8] L. Wang 376, 401 (2022). [9] K. Kimura et al., ACS photon. 8, 982 (2021).

Figure 1
A Novel Cancer Therapy Using Proton Beam: An Integrated Proton-Dynamic Therapy, iPDT
Authors: Matsui Hirofumi 
Published: August 2024

[Background and Aims]
A super-aged society, the prime example of which is Japan, is being flooded with increasing in numerous numbers of aged cancer patients, who often take anti-coagulant medicines to prevent the attacks of ischemic heart diseases and/ or strokes. Since they show bleeding tendency induced by the medicines, it’s hard for them to receive surgical operations. Thus, low invasive cancer treatments without bleedings are abundantly desired. In this study, the applicant will establish a new proton therapy, in which a resonance nuclear reaction (RNR) induced by collision of a proton with a stable nitrogen isotope (15N), can be a clue to injure cancer-cells specifically. The LET of the product ions (12C6+, 4He2+) of the 15N RNR is above 50 times in comparison with the LET of proton. To establish the cancer-specific 15N delivery, 15N-aminolevulinic acid (15N-ALA) will be used. This reagent has been already used and obtained regulatory approvals as a diagnostic medicine for the location of the glioblastoma in Japan.
[Methods]
In this study, a pair of rat gastric epithelial cells, one is normal cell RGM1, and another is cancerous characteristics cells RGK1 were used. The authors treated these cells with both 1mM 15N-ALA and 14N-ALA. Thereafter, we measured and compared porphyrin fluorescent intensity of these cells. Moreover, these cells will be irradiated with 4 nc proton beam generated by an electrostatic accelerator, then 4.43 MeV gamma-rays will be measured to demonstrate the amount of 15N collected specifically in the tumour cells. After these proton irradiations, cells were stained with hoechest33258 and dapi to observe cellular apoptosis.
[Results] Cancer cells accumulated 9 folds of 15N in comparison with normal epithelial cells. After 3hours of proton irradiation, both cancer cells and normal cells were not injured. However, almost all cancer cells were died with apoptosis while normal cells showed few cellular injuries after 24 hours.
[Conclusions] Cancer cells were completely killed by RNR involved with imM 15N-ALA and 4nc proton irradiation whereas this dose of proton showed few effects of ionizing radiation on normal cells. Thus, iPDT should be an ideal treatment for cancer. Moreover, the quantitative analysis of 15N in the tumour cells can be a new pre-diagnosis for iPDT.
Metallophthalocyanines as Outstanding Hole Transporting Materials in Perovskite Solar Cells
Authors: Sastre-Santos Angela 
Published: August 2024

Perovskite solar cells (PSCs) are promising candidates to reach the market to complement the current offer of photovoltaic cells although for such a thing they still have to overcome some challenges such as long-term stability. The hole transporting layer (HTL) is a crucial component in n-i-p PSC, since it must favor an adequate movement of charges and protect the perovskite layer from environmental conditions. In this sense, the commonly used HTL, spiro-OMeTAD, does not provide PSCs with sufficient stability and is too expensive. Cheaper molecular materials such as metallophthalocyanines are proving to be a good alternative, as they provide greater stability.[1]
In this communication, we will present novel ZnPcs and CuPcs monomers[2] (see as examples Figure 1), among others, as efficient, stable, and low cost HTMs in PSCs. The MPcs are substituted with functional groups that possesses a very good solubility in a wide range of organic solvents, adequate HOMO LUMO levels and their photovoltaics performance as high stable solution processing in a wide range of perovskite solar cell devices.

References

[1] a) D. Molina, J. Follana, Á. Sastre-Santos, J. Mater. C 10, 11975–11982 (2023). b) P. Huang, A. Hernández, J. Follana-Berná, S. Kazim, J. Ortíz, Á. Sastre-Santos, S. Ahmad, ACS Appl. Energy Mater. 4, 9, 10124–10135 (2021).
[2] a) A. Hernández, N. H. Hemasir, S. Kazim, J. Ortiz, S. Ahmad and Ángela Sastre-Santos 11, 8243-8253, (2023).

Figure 1
(Keynote) High-Performance Carbon Nanotube Transistors for Logic Platform
Authors: Li Shengman , Gilardi Carlo , Zeevi Gilad , Mitra Subhasish , Wong H.-S. Philip 
Published: August 2024

Low-dimensional 1D and 2D materials hold promise as candidate channel materials for highly scaled and high-performance transistors beyond the limits of silicon-based transistors. This talk will first motivate transistors built on low-dimensional channels due to the significant speed, energy efficiency, and transistor density benefits enabled by their electronic and physical properties. This talk will focus on 1D carbon nanotube (CNT) semiconductors and describe the advanced device component process modules that have been demonstrated, explaining both the fundamental mechanisms of operation and device-level performance objectives. Single-CNT FET experimental studies give insight into the quality of (1) low resistance N- and P- contacts down to 10 nm contact length, (2) high-capacitance gate dielectrics optimized for deposition on SP2 carbon surfaces, and (3) controlled N- and P- remote dielectric doping. To achieve high current density each transistor must contain multiple CNTs, therefore we will review state-of-the-art strategies to assemble densely aligned arrays of CNT with controlled CNT spacing between 2-10 nm and uniform electronic bandgap. The final portion of the talk will highlight recent advances from our team and others to integrate the best device components together to demonstrate high-performance carbon nanotube MOSFETs. We will elaborate on the remaining challenges and provide a summary of device design tradeoffs that will help guide future studies.
We are grateful for support and collaboration from TSMC Corporate Research, DoD, Stanford SystemX Alliance, Stanford Nanofabrication Facility, Stanford Nano Shared Facility, and the University of California at San Diego.
Exploring the Surface Stability of Non-Benzenoid and Non-Planar High-Membered Rings
Authors: Sánchez Carlos 
Published: August 2024

The synthesis of carbon-based nanomaterials has experienced an enormous advance in the last 15 years, in part motivated by the advent of On-surface Synthesis (OSS).1 This young field, based on the synthesis of carbon-based nanostructures directly on surfaces thanks to their unique catalytic properties, has allowed the formation of otherwise unattainable extended pi-conjugated systems, like atomically precise graphene nanoribbons,which turned out to be an excellent workbench to explore new physico-chemical properties at the atomic and molecular level.2

Once it was shown the feasibility to use this bottom-up approach to induce organic chemical reactions between tailored precursor monomers, the field evolved toward adding increasing complexity to the final products, either by modifying the dimensionality, edge structure and shape or by including heteroatoms or defects. All these approaches resulted in new intriguing properties as modified band structures or topological states. Of particular recent interest is the effect of non-benzenoid rings in the emergence of pi-magnetism, so far mainly focused on pentagonal rings.3 However, if we want to increase the versatility of the field and explore new possible functionalities associated to the presence of non-benzenoid rings in the nanostructures, it is mandatory to study their stability on surfaces.
In this talk, we will discuss the thermal stability of different high-membered non-benzenoid rings, specifically heptagons and octogons, when included into graphene-based nanostructures, paying special attention to the reaction mechanisms involved.

References

(1) Gourdon, A. On-Surface Covalent Coupling in Ultrahigh Vacuum. Angew. Chem. Int. Ed.
2008, 47 (37), 6950–6953. https://doi.org/10.1002/anie.200802229.
(2) Clair, S.; de Oteyza, D. G. Controlling a Chemical Coupling Reaction on a Surface: Tools and Strategies for On-Surface Synthesis. Chem. Rev.
2019, 119 (7), 4717–4776. https://doi.org/10.1021/acs.chemrev.8b00601.
(3) Oteyza, D. G. de; Frederiksen, T. Carbon-Based Nanostructures as a Versatile Platform for Tunable π-Magnetism. J. Phys. Condens. Matter
2022, 34 (44), 443001. https://doi.org/10.1088/1361-648X/ac8a7f.
Corrosion of Copper-Nickel Alloys in Seawater-Based Electrolytes
Authors: Anderson Rachel M. , Kinee WIlliam J , Policastro Steven A 
Published: August 2024

Copper nickel materials are used for their corrosion resistance due to the protective film that forms in seawater. The development of this film over time depends on the exposure condition, and it is critically important to understand the aging process for CuNi components used in marine systems to ensure passivity under sulfide contaminated conditions. Here we study the formation of the protective film over time and its effect on corrosion performance. Electrochemical impedance spectroscopy (EIS) measurements during exposure are used to develop a model of film growth on CuNi 70/30 alloys. These electrochemical measurements are coupled with surface analytical techniques such as glow discharge-optical emission spectroscopy (GD-OES) and X-ray photoelectron spectroscopy (XPS) to characterize the composition of the surface oxide. GD-OES results show that as the protective layer forms, nickel mainly remains at the metal surface and the outer layers are copper enriched oxides and chlorides. There is also incorporation of various elements from the seawater within the film. The rate of this film growth is correlated to the resulting decrease in corrosion rate. Different exposure conditions, such as under flow, are investigated.
The translation of these protective film mechanisms to additively manufactured CuNi materials is also of interest, to ensure similar performance with these materials. Evaluating corrosion performance of these newly developed materials involves careful comparison to existing knowledge of film growth and potential for breakdown.
A Review on CMP Challenges in HWB and Wafer Level Packaging
Authors: Basim G. Bahar 
Published: August 2024

Chemical mechanical planarization/polishing process faces new challenges in multiple new dimensions as hybrid wafer bonding (HWB) and flip-chip technologies evolve to enable innovative integration forms in semiconductor applications. The advanced capabilities of (i) manufacturing the CMOS independent of the memory array through HWB and, (ii) selecting the fully functional chiplets at the die level for heterogenous components for flip-chip bonding, drive cost-effective and high-performance integration.
This paper is a review of the CMP challenges as these new technologies demand additional capabilities such as bonding surface planarization in addition to TSV exposure and polishing ability for backside metallization, edge trimming as well as backside thinning. The toolsets and current capabilities are reviewed in addition to the forthcoming trends of manufacturing ultrathin wafers.
Enhancing Methylated Amorphous Silicon Anode Performances in Li-Ion Batteries By Boron Doping
Authors: Phung Tram Ngoc , Feng Yue , Poupardin Théodore , Rosso Michel , Henry-de-Villeneuve Catherine , Ozanam Francois 
Published: August 2024

Methylated amorphous silicon has already demonstrated some advantages as compared to silicon in terms of mechanical properties and cyclability for Li-ion batteries (LIB) [1]. However, the conductivity of methylated amorphous silicon drops by several orders of magnitude when increasing the methyl content in the material, which prevents investigating methyl contents higher than 10%. It is well known that doping significantly improves the conductivity of crystalline or amorphous silicon, and has sometimes been reported to improve the material cyclability when used as a LiB anode [2].
Here, boron-doped methylated amorphous silicon electrodes with different methyl contents were investigated as anodes for LiB in half-cell configuration. Boron doped methylated silicon thin films (100nm thick) with various methyl content were cycled in the range 0.025V – 1V at C/2 rate (electrolyte: LP30 with 5%FEC). 10% methylated amorphous silicon with 2% boron doping performs a capacity retention of 77% after 1000 cycles (exhibiting a capacity around 1800 mAh.g-1) of full lithiation/delithiation. Figure 1a shows a clearly improved performance as compared to the undoped material. The stability upon cycling of higher methyl contents (15% and 20%) electrodes is further increased, with a capacity retention exceeding 80% over 1000 cycles of full lithiation/delithiation.
The evolution of the SEI thickness can be quantitatively determined from IR spectra during cycling. The thickness in the delithiated state is found to increase from cycle to cycle, but with a lower rate for the doped 10% methylated electrodes (thickness lower than 25 nm after 40 cycles and 30 nm after 80 cycles) than for the undoped ones (thickness larger than 35 nm after 40 cycles), see Figure 1b. The SEI evolution upon cycling for higher methyl content is currently under investigation. Reference

[1]

L. Touahir, A. Cheriet, D. A. D. Corte, J.-N. Chazalviel, C. H. Villeneuve, F. Ozanam, I. Solomon, A. Keffous, N. Gabouze et M. Rosso, «Methylated silicon: A longer cycle-life material for Li-ion batteries,» Journal of Power Sources, vol. 240, pp. 551-557, 10 2013.

[2]

M. Salah, C. Hall, P. Murphy, C. Francis, R. Kerr, B. Stoehr, S. Rudd et M. Fabretto, «Doped and reactive silicon thin film anodes for lithium ion batteries: A review,» Journal of Power Sources, vol. 506, p. 230194, 9 2021.

Figure 1
The Effect of Structural Disorder on Li-Ion Transport in the Inorganic Components of the Electrode-Electrolyte Interfaces of Li-Ion Batteries
Authors: Adelstein Nicole , Jeong Wonseok , Weitzner Stephen Eric , Wan Liwen 
Published: August 2024

Conventional organic electrolytes in Li-ion batteries have an electrochemical window that is too narrow, leading to a decomposition at the cathode and anode surfaces, especially at high voltages. The breakdown of the electrolyte leads to the formation of cathode-electrolyte interphase (CEI) and solid-electrolyte interface (SEI) at the anode. These interfaces are a multicomponent, 3-dimensional heterogeneous structures that span from a few nanometers to micrometers. To understand the atomic-scale impact of the interfaces’ structure and chemistry on function we have run molecular dynamics simulations of the Li-ion diffusivity in the most likely components: LiF, Li2CO3, and Li2O. Our work focuses on identifying the effect of local chemistry and lattice structure in disordered or amorphous component materials on Li-diffusivity. We extract Li-ion diffusivity and the activation energy for Li-ion transport from both machine learning force fields and ab-initio molecular dynamics from the individual components of the interface and explicit interfaces. Post analysis establishes the local correlation between atomic structure, chemistry, and Li-ion migration. If well designed, the SEI and CEI can protect the electrolyte and cathode to prevent further degradation during cycling and thus optimization of battery performance.
This work was sponsored by the Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office and was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
High-Valence Ion Doped Compositionally Partitioned Li[Ni0.78Co0.10Mn0.12]O2 Cathode for Advanced Lithium-Ion Batteries
Authors: Kim Myoung-Chan , Park Geon-Tae , Sun Yang-Kook 
Published: August 2024

Numerous approaches have been employed to reduce the intrinsic instability of Ni-rich cathodes. Among them, the introduction of concentration gradient (CG), i.e., a strategy to protect the labile Ni-enriched compartment with a chemically protective Mn-rich shell, has proven successful in commercial applications.1 However, because the segmentation of transition metal (TM) constituents and the formation of unique geometric configurations are characteristics inherited from the CG hydroxide precursor; it is crucial to select the optimal calcination temperature and precisely control it.2 Excessive thermal energy input can result in concentration planarization because the CG of the hydroxide precursor is intrinsically susceptible to the interdiffusion of TM elements during lithiation. Moreover, the immoderate coarsening of the primary particles can eliminate the advantageous features of the CG design by producing equiaxed primary particles.2 In this study, we propose a strategy that can effectively ameliorate the deterioration of Ni-rich CG cathodes resulting from excessive thermal energy input and remarkably improve their electrochemical cycling performance. It was revealed that a trace amount of tungsten incorporation during the cathode calcination can effectively mitigate the high-temperature-induced cathode degeneration and maintain outstanding product quality over a wide range of temperatures. Thus, the proposed strategy opens new avenues for the facile synthesis of long-life Ni-rich CG cathodes.

Reference
s
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[1] Y.-K. Sun, S.-T. Myung, B.-C. Park, J. Prakash, I. Belharouak, K. Amine, Nat. Mater. 8 (2009) 320-324.
[2] G.-T. Park, H.-H. Ryu, T.-C. Noh, G.-C. Kang, Y.-K. Sun, Mater. Today 52 (2022) 9-18.
Improvement of Activation Processes for Lithium-Ion Secondary Battery through Electrochemical Characteristics
Authors: Kim Woojin , Shim Jae-Hyun 
Published: August 2024

A lithium-ion secondary battery that has not undergone the activation process may experience compromised cycleability and safety. Therefore, the activation process following the manufacturing of lithium-ion secondary batteries plays a crucial role in enhancing safety and extending cycleability. Through the pre-charging process of the activation procedure, additives within the electrolyte undergo chemical reactions at the anode interface, forming a thin solid layer on the anode surface. The solid layer formed on the anode surface through this process is referred to as the Solid Electrolyte Interphase (SEI) layer. The SEI (Solid Electrolyte Interphase) layer serves to inhibit direct decomposition reactions between the electrolyte and the anode interface, similar to the role of a separator. It can contribute to long-term lifespan and safety. However, if formed beyond a certain thickness, the SEI (Solid Electrolyte Interphase) layer may go beyond the function of a separator and instead develop into a single, thick solid layer. Furthermore, if formed below a certain thickness, the SEI (Solid Electrolyte Interphase) may easily collapse, failing to fulfill the role of the solid layer and leading to issues of capacity loss and safety concerns. Therefore, the process of creating a robust SEI (Solid Electrolyte Interphase) layer with a consistent thickness, without deviation, is of utmost importance.
In this study, to enhance the activation process, a Double Layer Cell (DLC) with a capacity of 80 mAh was manufactured, and the State of Charge (SOC, %) during the pre-charging process was adjusted. To create a robust SEI (Solid Electrolyte Interphase) layer, the State of Charge (SOC, %) was maintained at 20%, 50%, and 80% after pre-charging at temperatures of 25°C, 45°C, and 60°C for a specified duration in each formation process. During these formation processes, impedance analysis (EIS) was employed to evaluate the resistance of the cell itself and the interface resistance in relation to changes in SOC (%) and temperature. Additionally, the crystal structure of the SEI was elucidated through XRD. Furthermore, chemical characteristics and bonding states of the cathode surface were analyzed using XPS. The morphology and composition of the SEI were observed through SEM and EDS, providing an analysis of the components of the SEI. Subsequently, the DLC was subjected to output verification through C-rate at room temperature based on SOC (%). The electrochemical characteristics were evaluated by measuring the cycleability of 1000 cycles at both room temperature and high temperature, assessing the impact of the pre-charging process.