bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Exploring and Manipulating Luminescence Centers in Lead Halide Perovskites through Hydrostatic Pressure
Authors: Bao Jiming 
Published: August 2024

The application of hydrostatic pressure to materials induces changes in lattice constants, vibrational spectra, and electron-phonon interactions, thereby altering the optoelectronic properties of semiconductors. Consequently, hydrostatic pressure has become a widely utilized tool for investigating and enhancing the optical properties of organic/inorganic halide perovskites and their nanostructures. In this presentation, I will discuss the impact of hydrostatic pressure on two distinct types of luminescence centers in perovskite materials. The first type of luminescence centers originates from excitons within perovskite nanocrystals. I will discuss how hydrostatic pressure serves as a valuable tool for elucidating the origin of luminescence in low-dimensional perovskites, including 2D CsPb2Br5, 0D Cs4PbBr6, and 2D Ruddlesden-Popper Hybrid Perovskite Crystals. The second type of luminescence centers exhibit broadband optical emission from self-trapped excitons in low-dimensional perovskites. I will present our findings on the observation of strong exciton-phonon coupling and demonstrate how hydrostatic pressure can be employed to modulate electron-phonon coupling, offering a means to finely tune the broad emission spectrum.
References:
[1] J. Bao, V. G. Hadjiev, “Origin of Luminescent Centers and Edge States in Low-Dimensional Lead Halide Perovskites: Controversies, Challenges and Instructive Approaches”. Nano-Micro Lett. 11,
26 (2019).
[2] Chong Wang, Yanan Wang, Xinghua Su, Viktor G. Hadjiev, Shenyu Dai, Zhaojun Qin, Hector A Calderon Benavides, Yizhou Ni, Qiang Li, Jie Jian, Md Kamrul Alam, Haiyan Wang, Francisco C. Robles-Hernandez, Yan Yao, Shuo Chen, Qingkai Yu, Guoying Feng, Zhiming Wang, Jiming Bao, “Extrinsic Green Photoluminescence from the Edges of Two-dimensional Cesium Lead Halides”, Advanced Materials
31, 1902492 (2019).
[3] Zhaojun Qin, Shenyu Dai, Viktor G. Hadjiev, Chong Wang, Lixin Xie, Yizhou Ni, Chunzheng Wu, Guang Yang, Shuo Chen, Liangzi Deng, Qingkai Yu, Guoying Feng, Zhiming M. Wang, Jiming Bao, “Revealing the Origin of Luminescence Center in 0D Cs4PbBr6 Perovskite”, Chem. Mater.
31, 9098-9104 (2019).
[4] Zhaojun Qin, Shenyu Dai, Chalapathi Charan Gajjela, Chong Wang, Viktor G Hadjiev, Guang Yang, Jiabing Li, Xin Zhong, Zhongjia Tang, Yan Yao, Arnold M Guloy, Rohith Reddy, David Mayerich, Liangzi Deng, Qingkai Yu, Guoying Feng, Hector A Calderon, Francisco C Robles Hernandez, Zhiming M Wang, Jiming Bao, “Spontaneous Formation of 2D/3D Heterostructures on the Edges of 2D Ruddlesden-Popper Hybrid Perovskite Crystals”, Chem. Mater. 32, 5009 (2020).
[5] Shenyu Dai, Xinxin Xing, Viktor G. Hadjiev, Zhaojun Qin, Tian Tong, Guang Yang, Chong Wang, Lijuan Hou, Liangzi Deng, Zhiming Wang, Guoying Feng, Jiming Bao, “Theory and experiments of pressure-tunable broadband light emission from self-trapped excitons in metal halide crystals”, Materials Today Physics
30, 100926 (2023).
Probing Interfacial Degradation in Solid-State Batteries Using Machine Learning Force Fields
Authors: Kim Kwangnam , Yuan Suyue , Dive Aniruddha Mukund , Grieder Andrew , Adelstein Nicole , Kang Shinyoung , Wood Brandon C. , Wan Liwen 
Published: August 2024

Solid-state batteries (SSBs) are next-generation energy storage technologies with improved safety and potentially higher energy densities compared to conventional Li-ion batteries, which is enabled by using fast ion-conducting solid electrolytes (SEs). However, practical applications of SSBs are hindered by the electro-chemo-mechanical instabilities at interfaces within the SEs (grain boundaries (GBs)) and between SEs and the electrodes, which deteriorates Li transport and the chemical and mechanical integrity of the cell. To mitigate, fundamental understanding of the intrinsic physico-chemical properties at interfaces is required. To this end, we directly probe atomic structures of the interfaces and GBs by performing large-scale atomistic simulations, enabled by validated machine-learning force fields (MLFFs) and resolve the structure-property relationship at complex interfaces that governs Li-ion transport and stability of SSBs.
In this talk, we will discuss the characteristics of garnet Li7La3Zr2O12 (LLZO) SE/LiCoO2 (LCO) cathode interfaces as well as the internal interfaces within the LLZO (GBs). It is observed from our simulations that the propensities for interfacial degradation strongly depend on the surface chemistry of LLZO and LCO. Doping LLZO is found to have a segregation effect at the LLZL GBs, here we will discuss its implication towards secondary phase formation and Li transport kinetics. At last, we will address the impact of interfaces on micro-crack propagation behavior in the LLZO-LCO system. In summary, our results reveal how atomic details of the dynamically evolving interfaces dictate the performance of SSBs, and provide guidance for processing and interface design to achieve desired performance .
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract number DEAC52-07NA27344. Authors acknowledge funding support from the Vehicle Technologies Office, Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy and computational resource support from the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program. This research used resources of the Argonne Leadership Computing Facility, which is a DOE Office of Science User Facility supported under Contract DE-AC02-06CH11357.
Stable Hydroborate Solid-State Lithium Battery with High-Voltage NMC811 Cathode
Authors: Braun Hugo , Asakura Ryo , Remhof Arndt , Battaglia Corsin 
Published: August 2024

Hydroborate solid electrolytes offer high ionic conductivity and are stable in contact with alkali metal anodes, but are challenging to integrate into batteries with high-voltage cathodes [1-3]. Here, we demonstrate stable dis-/charge cycling of solid-state lithium-ion batteries combining a Li3(CB11H12)2(CB9H10) hydroborate electrolyte with a 4 V-class LiNi0.8Mn0.1Co0.1O2 (NMC811) cathode, exploiting the enhanced kinetic stability of the LiCB11H12-rich and LiCB9H10-poor electrolyte composition [4]. Cells with lithium metal and indium/lithium anodes achieve a discharge capacity at C/10 of ~145 mAh g–1 at room temperature and ~175 mAh g–1 at 60 °C. Indium/lithium cells retain 98% of their initial discharge capacity after 100 cycles at C/5 and 70% after 1000 cycles at C/2. Capacity retention of 97% after 100 cycles at C/5 and 75% after 350 cycles at C/2 is also achieved with a graphite anode without any excess lithium. The energy density per cathode composite weight of 460 Wh kg–1 is on par with the best solid-state batteries reported to date.
[1] L. Duchêne, A. Remhof, H. Hagemann, D. Battaglia, Energy Storage Materials, 2020, 225, 782
[2] L. Duchêne, R.-S. Kühnel, E. Stilp, E. Cuervo Reyes, A. Remhof, H. Hagemann, C. Battaglia, Energy & Environ. Science, 2017, 10, 2609
[3] R. Asakura, D. Reber, L. Duchêne, S. Payandeh, A. Remhof, H. Hagemann, C. Battaglia, Energy & Environ. Science, 2020, 13, 5048
[4] H. Braun, Ryo Asakura, A. Remhof, C. Battaglia, ACS Energy Lett. in press
Understanding Ni-Rich Layered Cathode Materials for Fast-Charging Li-Ion Batteries
Authors: Ryu Hoon-Hee , Murugan Vivekanantha , Chen Guoying 
Published: August 2024

The market for electric vehicles (EVs) has experienced significant growth, and this trend is expected to continue in the coming years. While the lithium-ion battery (LIB) technologies for EVs have made significant progress so far, they still face several disadvantages compared to the internal combustion engines. A predominate challenge is reducing battery charging time. [1]

Traditional LIBs typically use Li[Ni1-x-yCox(Mn and/or Al)y]O2 as cathode materials. To improve the driving range of EVs, energy density has been the focus of research and development in the past decade, which led to the wide adoption of Ni-rich (Ni content > 80%) layered oxide cathodes in LIBs.[2] With increasing Ni content, however, the structural changes that the cathode material undergoes during electrochemical reactions also become more severe, which negatively impact their fast-charging performances.[3-5]

It is evident that addressing the fast charging limitations requires a deep understanding of the active materials. In this presentation, we show our recent effort in improving fast charging performances of Ni-rich layered cathodes. As the reactivity of Li[Ni1-x-yCox(Mn and/or Al)y]O2 cathodes vary with the states of dis/charges, their fast charging performances are directly linked to the charging/discharging protocol. In addition, we report how various physical properties of the cathode materials, such as microstructures and facets, can affect kinetics and charging rates. Our perspectives on future development strategies for fast charging Ni-rich layered cathode materials will also be discussed.
[1] X. Wang, Y.-L. Ding, Y.-P. Deng, Z. Chen, Adv. Energy Mater. 2020, 10, 1903864.
[2] S.-T. Myung; F. Maglia; K.-J. Park; C. S. Yoon; P. Lamp; S.-J. Kim; Y.-K. Sun, ACS Energy Lett. 2017, 2, 196.
[3] F. Schipper; E. M. Erickson; C. Erk; J.-Y. Shin; F. F. Chesneau; D. Aurbach, J. Electrochem. Soc. 2017, 164, A6220.
[4] H.-H. Ryu, K.-J. Park, C. S. Yoon, Y.-K. Sun, Chem. Mater. 2018, 30, 1155.
[5] J. Park, H. Zhao, S. D. Kang, K. Lim, C.-C. Chen, Y.-S. Yu, R. D. Braatz, D. A. Shapiro, J. Hong, M. F. Toney, M. Z. Bazant, W. C. Chueh, Nat. Mater. 2021, 20, 991.
Effect of Water–Soluble Polyimide (w-PI) Type Binders on the Performance of High-Capacity Silicon Anodes of Lithium-Ion Batteries
Authors: Cheon Sehwa , Park Eun-jin , Park Se-Jin , Lee Ho-bong , Gendensuren Bolormaa , OH Eun-Suok 
Published: August 2024

In order to enhance rapid charging and driving range for electric vehicles, the high-capacity of lithium-ion batteries (LIBs) is imperative. Commercially available graphite as an anode material has long cycle life, abundance, and low cost. However, it has a limitation in its theoretical specific capacity (372 mAh g−1).
To overcome this limitation, much attention has been paid to silicon (Si), which offers a high theoretical specific capacity of 4,200 mAh g−1. Nevertheless, silicon suffers from excessive volume expansion, resulting in issues such as pulverization of active alloy particles, delamination, and the formation of an unstable Solid Electrolyte Interphase layer. This lead to a limitation to use the silicon in large amount in an electrode. A polymeric binder has a critical role in improving the high-capacity Si anode. Conventional polyimide (PI), one of various super-engineering plastics, was applied to the Si anodes, but it is still challenged to water-insolublity and high temperature imidization process around 300 oC. In this study, a water-soluble PI (w-PI) is designed by the polycondensation between dianhydrides and diamine in water environment. In addition, a relatviely low-temperature imidization temperature below 200 oC will be appled by the introduction of dimethylimidazole. This study will briefly outline the direction for implementing a w-PI binder and improving electrochemical performance of high-capacity anode compared to conventional binders such as PVdF and CMC/SBR.

Keyword: high-capacity Si anode; dianhydrides and diamine; Polyimide (PI); and water-soluble PI

Figure 1
Investigating of Carbon Agent Distribution Using Long-Chain Alkyl in Grafted Binder for High-Capacity SiOx/Graphite Anode
Authors: Gendensuren Bolormaa , KIM Minjae , Sugartseren Nyambayar , OH Eun-Souk 
Published: August 2024

A small amount of the conductive carbon agent in lithium-ion battery (LIB) formulation has a significantly impact on the rate capability performance of battery but the distribution problem of the carbon conductive material is issued in the electrode slurry due to its hydrophobic and inert characteristics. To overcome this problem, the use of dispersant agent was proposed in the electrode fabrication process.
In this study, the grafting of adhesive acrylamide monomer (AM) and a long-chain alkyl monomer onto carboxymethyl cellulose (CMC) is applied to binder to improve the conductive agent distribution in a high-capacity SiOx/C anode. The long alkyl chain in the monomer of the graft copolymer binder exhibits good dispersibility of the carbon agent and improved conductive matrix compared to the binder with no alkyl monomer. This may be explained by CH-π integration between the alkyl monomer in graft polymer and carbon agent. The high-capacity SiOx/C anode with the long-alkyl chain introduced graft binder is examined in the slurry level with rheology and dispersion stability, in the electrode sheet level with electric resistance, peel-off, and coin-cell level with various electrochemical performance, charge/discharge performance.

Keywords: Silicon oxide; Graphite; Carbon agent distribution, long-chain alkyl monomer; Acrylamide; Graft copolymer

Figure 1
Rapid in-Situ Electrochemical Formation of Partially Disordered Spinel from Mn-Rich Disordered Rocksalt Cathodes
Authors: Holstun Tucker , Mishra Tara , Huang Liliang , Yang Xiaochen , Ceder Gerbrand 
Published: August 2024

We present the development of an electrochemical formation method that enables rapid and in-situ formation of a partially disordered spinel phase from an initially disordered rocksalt (DRX) cathode. Recent studies on Mn-rich DRX materials have demonstrated the emergence of a spinel-like phase during cycling, resulting in improved capacity retention, energy density, and rate capability compared to materials which do not transform1,2,3. However, this transformation process typically requires weeks of cycling at relatively low rates, posing significant challenges for the commercialization of such materials.
To gain a deeper understanding of this transformation process, we carry-out a systematic study to determine whether the formation process of these spinel-like materials can be accelerated through a precycling formation process. By employing a novel electrochemical approach to purposefully stimulate the transformation, we successfully reduce the time required from several weeks to as little as one day for Mn-rich DRX. Extended cycling and synchrotron X-ray diffraction confirm that these materials exhibit both equivalent performance and resulting structure to those obtained through conventional cycling over a much longer duration. Further characterization of this material using HAADF and 4-D STEM reveals the complex local structure of the spinel-like partial ordering. It is hoped that such a practical electrochemical formation method will allow for an acceleration of research on these earth-abundant and energy-dense materials.

Li, L.; Lun, Z.; Chen, D.; Yue, Y.; Tong, W.; Chen, G.; Ceder, G.; Wang, C. Fluorination-Enhanced Surface Stability of Cation-Disordered Rocksalt Cathodes for Li-Ion Batteries. Adv Funct Mater 2021, 31 (25), 2101888. https://doi.org/10.1002/adfm.202101888.

Ahn, J.; Giovine, R.; Wu, V. C.; Koirala, K. P.; Wang, C.; Clément, R. J.; Chen, G. Ultrahigh-Capacity Rocksalt Cathodes Enabled by Cycling-Activated Structural Changes. Adv. Energy Mater. 2023. https://doi.org/10.1002/aenm.202300221.

Cai, Z.; Ouyang, B.; Hau, H.-M.; Chen, T.; Giovine, R.; Koirala, K. P.; Li, L.; Ji, H.; Ha, Y.; Sun, Y.; Huang, J.; Chen, Y.; Wu, V.; Yang, W.; Wang, C.; Clément, R. J.; Lun, Z.; Ceder, G. In Situ Formed Partially Disordered Phases as Earth-Abundant Mn-Rich Cathode Materials. Nat. Energy 2023, 1–10. https://doi.org/10.1038/s41560-023-01375-9.
Low-Temperature Anodization: An Electrochemical Route to Tailored Nanostructures in Heavily Doped p-Type Silicon for Forming Quantum Dots
Authors: Chiou Yu-Sheng , Liu Cheng-Ying , Wu Chun-Huang , Li Shu-Cheng , Huang Wei-Chi , Cheng Chao-Chia , Lee Benjamin T.-H. 
Published: August 2024

This study presents a pioneering electrochemical approach to tailor the anodization outcomes of heavily doped p-type silicon, a subset of low-resistivity semiconductor materials, via low-temperature anodization. Conventionally, anodizing such silicon in hydrofluoric acid at room temperature leads to the formation of coarse porous silicon with negligible photoluminescence (PL) upon exposure to ultraviolet (UV) radiation.
In this investigation, we embark on an unconventional path by conducting the anodization process at an exceptionally low temperature of -20°C. This seemingly subtle adjustment, however, triggers a remarkable transformation in the optical characteristics of the silicon substrate. Strikingly, the anodized surface, when illuminated with UV radiation, emits a vibrant and distinct red PL signal (Figure 1), signifying the emergence of quantum confinement effects attributable to nanocrystals, i.e., quantum dots.
To substantiate the existence of these nanostructures, we employ advanced characterization techniques, with a focus on transmission electron microscopy (TEM). These rigorous analyses confirm the presence of well-defined silicon nanocrystals, typically measuring within the 3~4 nm range (Figure 2), meeting the prerequisites for quantum confinement effects. Notably, it is worth mentioning that the formation of such nanostructures is unattainable on heavily boron-doped silicon due to its high etching rate.
In conclusion, our findings underscore the potential of low-temperature anodization as a versatile tool to tailor the luminescent properties of porous silicon at the nanoscale. This breakthrough not only advances our fundamental comprehension of semiconductor electrochemistry but also holds the promise of driving progress in electrochemical fabricating semiconductor quantum dots and optoelectronics.

Figure 1
(Invited) Heavy-Metal-Free Quantum Dot Thin-Film Photodetectors for SWIR Imaging: A Comprehensive Analysis for Performance Enhancement
Authors: Lieberman Itai 
Published: August 2024

Various emerging technologies investigate the ability to sense and detect light in the shortwave infrared spectrum (wavelengths between 1100nm and 2500nm). Autonomous cars, smart agriculture, eye tracking for AR and VR applications, face recognition, surveillance, machine vision and new microscopy techniques can take advantage of additional information found in SWIR.
Thin film photodetectors, based on quantum dot photodiodes, show promise in bringing SWIR sensing to the mass markets by offering simpler and cheaper processes and higher resolution than existing technologies. However, the prevalent use of lead (Pb), Cadmium (Cd) and mercury (Hg) in existing quantum dot thin film photodetectors poses safety, environmental and regulatory challenges, limiting their widespread adoption.
InAs quantum dots emerge as a leading alternative, offering a heavy metal free solution and paving the way for the next generation of SWIR imaging devices. Nevertheless, a nuanced understanding of InAs-based devices is imperative for unlocking their full potential and optimizing performance. This work presents a meticulous and extensive analysis conducted in our laboratories, encompassing both devices and materials. The resulting insights empower an agile and informed redesign of the photodiode, showcasing tangible improvements in performance metrics.
(Invited) Development of Ag- and Sn-Based Colloidal Quantum Dots for Near Infrared Photodetection
Authors: Ouyang Jianying , Graddage Neil , Lu Jianping , Martin Barbara , Davidson-Hall Tyler , Tao Ye , Ding Jianfu , Malenfant Patrick 
Published: August 2024

Low-cost photodetectors with sensitivity in the second near-infrared window (NIR-II, 1000–1700 nm) are highly demanded. Recently, we made the first demonstration of an Ag2Se colloidal quantum dots (QDs) photodiode with sensitivity up to 1200 nm. By employing secondary phosphine to elevate the precursor reactivity, the Ag2Se QDs with a distinct excitonic absorption peak was achieved. These nanocrystals were deposited from solution into a mesoporous TiO2 scaffold to increase the light absorption and charge separation and reduce the exciton diffusion length. By incorporating a suitable hole-transporting layer between the active layer and Ag anode, the resulting devices showed a responsivity of 4.17 mA/W at 1200 nm.1 Also, Ag2Te QDs are excellent for advancing the detection wavelength. Their synthesis with desired particle sizes, narrow size distribution and high photoluminescence quantum yield (PL QY) is challenging. We systematically investigate critical parameters affecting the synthesis in an organic phase. It shows that high Ag/Te feed ratio leads to smaller size and higher PL QY; under 4:1 Ag/Te feed molar ratio, addition of secondary phosphine leads to narrower size distribution and excellent colloidal stability; under 6:1 Ag/Te feed molar ratio, excess 1-dodecanethiol as a strong ligand slows the nucleation and results in fewer nuclei, leading to a broad size distribution and poor optical properties; additional n-trioctyl phosphine as a weak ligand provides better colloidal stability; and another weak ligand n-tributylphosphine improves Ag2Te QD colloidal stability, focuses size distribution, and enhances PL QY. After optimization relatively large Ag2Te QDs with distinct excitonic absorption peaks (~1050 – 1450 nm) and PL emission peak 1.3 – 1.7 µm (QY up to 6.2%) were obtained. NIR-II photodetection has been demonstrated with a responsivity of ~1.5 mA/W at 1400 nm.2 More recently, we have been developing Sn-based chalcogenide QDs and obtained preliminary photodetection results. These results demonstrate that Ag and Sn chalcogenide QDs offer a low-toxicity route for low-cost fabrication of NIR-II photodetection.

Reference:

[1] Graddage N, Ouyang J, Lu J, Chu TY, Zhang Y, Li Z, Wu X, Malenfant PRL, Tao Y. Near-Infrared-II Photodetectors Based on Silver Selenide Quantum Dots on Mesoporous TiO2 Scaffolds. ACS Applied Nano Materials 2020, 3: 12209–12217.
[2] Ouyang J, Graddage N, Lu J, Zhong Y, Chu TY, Zhang Y, Wu X, Kodra O, Li Z, Tao Y, Ding J. Ag2Te Colloidal Quantum Dots for Near-Infrared-II Photodetectors. ACS Applied Nano Materials 2021, 4: 13587–13601.

Keywords: Environmentally Friendly; Near Infrared; Quantum Dots; Photodetection.