Article
Chemistry, Physical
Dongke Li, Jiaming Chen, Zhaoguo Xue, Teng Sun, Junnan Han, Wanghua Chen, Etienne Talbot, Remi Demoulin, Wei Li, Jun Xu, Kunji Chen
Summary: Understanding the distribution and behavior of dopants in silicon nanocrystals is crucial for achieving controllable doping at the nanoscale and developing next-generation optoelectronic devices. This study investigates the atomic-scale distributions of phosphorus and boron dopants in silicon nanocrystal multilayers. The results show that phosphorus dopants mainly concentrate on the surfaces of silicon nanocrystals to passivate dangling bonds and provide free electrons, while boron dopants exhibit a different distribution pattern, forming a dopant-shell covering on the surfaces of silicon nanocrystals and leading to damage in the crystalline lattice.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Koichiro Suzuki, Toshihiro Kuzuya, Yasushi Hamanaka
Summary: Surface modification plays a crucial role in improving fluorescence properties of semiconductor nanoparticles. The bandedge emission characteristic has been observed in AgInS2 NPs but not in most other I-III-VI2 NPs. In this study, luminescence modifications of CuInS2 NPs were examined after postsynthesis treatment with TOP ligands. Although the bandedge emission was not generated, the TOP treatment significantly improved the luminescence quantum yield.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Tobias Hartl, Daniel Herrmann, Moritz Will, Yannic Falke, Alexander Grueneis, Thomas Michely, Pantelis Bampoulis
Summary: This article reports on the fabrication of stable silicon nanocluster arrays on a special surface. The cluster binding sites, electronic structure, and thermal stability were studied using scanning tunneling microscopy and spectroscopy. The findings show that the clusters have a size-dependent bandgap and are stable up to 577 K.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Optics
Mengyang Hao, Shun Cheng, Ye He, Weidong Xiang, Nan Ding, Wen Xu, Chong-Geng Ma, Xiaojuan Liang
Summary: A Dy3+-CPCB NCsG material is synthesized in borosilicate glass, which greatly improves the photoluminescence quantum yield and stability of Si photodetectors through the doping of Dy3+.
LASER & PHOTONICS REVIEWS
(2023)
Article
Physics, Applied
Yupengxue Ma, Ruoyu Wang, Xiaoru Qin, Qing Zhang, Xiaoxia Zhong
Summary: Environmentally friendly and fast synthesis of silicon quantum dots (SiQDs) is achieved with the help of plasma. The optimization of precursor concentration, reaction time, and other parameters can effectively improve the quantum yield (QY) of SiQDs. By utilizing the amidation and condensation reactions of DAMO and citric acid, this study successfully increases the QY of SiQDs from 4.23% to 23.9%, providing a promising approach for further improvement.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Multidisciplinary Sciences
Shuo Wang, Qian Zhao, Abhijit Hazarika, Simiao Li, Yue Wu, Yaxin Zhai, Xihan Chen, Joseph M. Luther, Guoran Li
Summary: A detailed picture of temperature dependent behavior of Cs(x)FA(1-x)PbI(3) perovskite quantum dots is constructed by in situ optical spectroscopic and structural measurements. The thermal degradation mechanism depends on both the exact chemical composition and the ligand binding energy. Cs-rich quantum dots undergo a phase transition from black gamma-phase to yellow delta-phase, while FA-rich quantum dots directly decompose into PbI2. Quantum dot growth is observed at elevated temperatures. FA-rich quantum dots exhibit stronger electron-longitudinal optical phonon coupling, leading to a higher probability of exciton dissociation compared to Cs-rich quantum dots. Surface ligand-induced strain enables full-range A-site tuning.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Natalia Bushlanova, Vladimir Baturin, Sergey Lepeshkin, Yurii Uspenskii
Summary: Silicon nanocrystals have significant potential in various applications, with their structural morphology and photo-physical characteristics being sensitive to hydrogenation degree. The clusters of hydrogen-passivated silicon can undergo different structural types, with a key importance on removing dangling bonds and passivating surface broken bonds.
Article
Chemistry, Multidisciplinary
Nande Mgedle, Olanrewaju A. Aladesuyi, Thabang Calvin Lebepe, Vuyelwa Ncapayi, Oluwatobi Samuel Oluwafemi
Summary: In this study, ZnCuInS/ZnS-ZnS multi-shell quaternary quantum dots (QDs) were synthesized as a nanosensor for the selective detection of Cu2+ ions. The as-synthesized QDs were spherical with a particle diameter of 3.66 +/- 0.81 nm and emitted in the first near-infrared window (725 nm) with an average decay PL lifetime of 43.69 ns. The developed multi-shell QDs exhibited selectivity towards Cu2+ ions through fluorescence quenching, with a detection limit of 1.4 mu M, which is below the acceptable limit in drinking water.
GREEN PROCESSING AND SYNTHESIS
(2023)
Article
Chemistry, Multidisciplinary
Surendra B. Anantharaman, Joachim Kohlbrecher, Gabriele Raino, Sergii Yakunin, Thilo Stoferle, Jay Patel, Maksym Kovalenko, Rainer F. Mahrt, Frank A. Nuesch, Jakob Heier
Summary: The photoluminescence quantum yield of cyanine J-aggregates can increase by an order of magnitude in blend solutions of water and alkylamines at room temperature. Time-resolved photoluminescence studies show an increased exciton lifetime as a result of suppressing non-radiative processes. Small-angle neutron scattering studies suggest the formation of highly emissive J-aggregates requires a sharp water/amine interface and the coexistence of nanoscale-sized water and amine domains.
Article
Crystallography
Wanying Gu, Yicheng Zeng, Yuan Deng, Pan Huang, Geyu Jin, Fangze Liu, Jing Wei, Hongbo Li
Summary: In this study, we successfully synthesized orthorhombic Cs2CuCl4 nanocrystals with a well-defined cubic shape and an average diameter of 24±2.1 nm via a colloidal synthesis route. The Cs2CuCl4 nanocrystals exhibited bright, deep blue photoluminescence, attributed to Cu(II) defects. Furthermore, passivating the Cs2CuCl4 nanocrystals with Ag+ effectively improved the photoluminescence quantum yield (PLQY) and environmental stability.
Review
Chemistry, Multidisciplinary
Yize Su, Chenhao Wang, Zijian Hong, Wei Sun
Summary: Silicon nanocrystals have drawn significant attention in recent decades for their unique luminescent properties, with thermal disproportionation method offering precise control over their size and structure, showing promising industrial applications. Research has shown that factors such as temperature, Si/O ratio, and surface groups play a crucial role in determining the properties of silicon nanocrystals.
FRONTIERS IN CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Youhui Zhou, Yao Cheng, Ju Xu, Hang Lin, Yuansheng Wang
Summary: Recent discoveries have uncovered the temperature-dependent upconversion luminescence behavior of inert-core/active-shell UCNPs, where both the sensitizer and activator are located near the nanoparticle surface, leading to a stronger luminescence thermal enhancement tendency compared to active-core UCNPs. This thermal enhancement behavior appears to be core-size dependent and is suggested to be attributed to the alleviation of surface quenching induced by lattice thermal expansion, based on the relationship between size-dependent luminescence and lattice expansion coefficient.
Article
Chemistry, Physical
Chang-Xu Li, Seung-Bum Cho, Dong-Hwan Kim, Il-Kyu Park
Summary: The lead-free copper-based perovskite Cs3Cu2X5 nano-crystals have garnered significant interest as active materials in optoelectronic devices due to their high emission stability, unique self-trap exciton emission, and high quantum yield. A strategy for increasing the yield and controlling the size of Cs3Cu2X5 nano-crystals by utilizing a metal halide additive has been proposed, leading to the synthesis of monodisperse Cs3Cu2I5 nanocubes with a photoluminescence quantum yield of 72.4%. This unique approach highlights the critical role of the metal halide additive in increasing synthesis yield and controlling the size of copper-based Cs3Cu2I5 nano-crystals based on precise mechanistic studies.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Xavier Le Guevel, K. David Wegner, Christian Wuerth, Vladimir A. Baulin, B. Musnier, V Josserand, U. Resch-Genger, Jean-luc Coll
Summary: This study investigates the influence of solvent polarity and surface ligand rigidification on the SWIR emission profile of gold nanoclusters with an anisotropic surface. The results show a significant enhancement of the SWIR emission band at 1200 nm in different local environments: solution, polymer composites, and solids. SWIR in vivo imaging of mice after intravenous administration of these gold nanoclusters, assisted by deep learning, provides high definition pseudo-3D views of vascular blood vessels.
CHEMICAL COMMUNICATIONS
(2022)
Article
Optics
Dongke Li, Jiaming Chen, Teng Sun, Yangyi Zhang, Jun Xu, Wei Li, Kunji Chen
Summary: Phosphorus/boron co-doping in Si quantum dots/SiO2 multilayers enhances subband light emission, with increasing B co-doping ratio resulting in improved emission intensity nearly two orders of magnitude stronger than solely P-doped samples. This enhancement is attributed to B dopants passivating surface dangling bonds, leading to suppressed phosphorus-related deep level emission and appearance of emission centered around 1400 nm in high B co-doping ratios.
Article
Microscopy
Xiaohui Huang, Dzmitry Hlushkou, Di Wang, Ulrich Tallarek, Christian Kubel
Summary: This study systematically investigates the reconstruction reliability of three mainstream algorithms in mesoporous materials. The results show that DART outperforms the other two methods in reliably revealing small pores and narrow channels, especially when the number of projections is strongly constrained.
Article
Nanoscience & Nanotechnology
L. Morsdorf, A. Kashiwar, C. Kuebel, C. C. Tasan
Summary: Tempering is commonly used in high strength steel microstructures to rearrange carbon atoms, but its nano-scale interaction with crystallographic defects is challenging to observe experimentally. In this study, we investigate the redistribution of carbon atoms along martensite grain boundaries in low carbon steel after quenching and tempering using transmission electron microscopy (TEM) and atom probe tomography (APT). Our findings reveal that the amount of carbon segregation to martensite grain boundaries depends on the boundary type, and the growth behavior of cementite precipitates differs at low- and high-angle grain boundaries due to crystallographic constraints. We also demonstrate the impact of carbon redistribution on the mechanical properties by comparing hardness results from boundary-containing probe volumes to nanoindentation results from pure bulk martensite volumes.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Chemistry, Physical
Till Ortmann, Simon Burkhardt, Janis Kevin Eckhardt, Till Fuchs, Ziming Ding, Joachim Sann, Marcus Rohnke, Qianli Ma, Frank Tietz, Dina Fattakhova-Rohlfing, Christian Kuebel, Olivier Guillon, Christian Heiliger, Juergen Janek
Summary: In recent years, reversible alkali metal anodes using solid electrolytes have been explored to increase the energy density of next-generation batteries. Na3.4Zr2Si2.4P0.6O12 has demonstrated potential as a solid electrolyte for solid-state sodium batteries due to its high ionic conductivity and stability with sodium metal. Analysis techniques such as impedance analysis, X-ray photoelectron spectroscopy, and transmission electron microscopy have revealed the formation of a stable interphase at the Na|Na3.4Zr2Si2.4P0.6O12 interface. The study provides valuable insights into the evaluation of sodium metal anode performance in solid-state batteries.
ADVANCED ENERGY MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Fabian Schackmar, Felix Laufer, Roja Singh, Ahmed Farag, Helge Eggers, Saba Gharibzadeh, Bahram Abdollahi Nejand, Uli Lemmer, Gerardo Hernandez-Sosa, Ulrich W. Paetzold
Summary: Vacuum-assisted growth (VAG) control is a promising method for controlling nucleation and crystallization of lead halide perovskite-based layers. Real-time monitoring of the VAG process is crucial for fabricating high-quality thin films. A multichannel photoluminescence and reflection imaging system is developed and used for in situ analysis of drying, nucleation, and crystal growth during VAG.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Chemistry, Multidisciplinary
Xiaohui Huang, Ilaria Barlocco, Alberto Villa, Christian Kuebel, Di Wang
Summary: Electron tomography was utilized to investigate the leaching and redeposition of a Pd@CMK3 catalyst during formic acid decomposition in batch and fixed bed reactors. The 3D distribution of Pd nanoparticles on CMK3 was determined by quantitative tomographic analysis, and the determined structural changes were correlated with the observed differences in activity and stability of formic acid decomposition using batch and fixed bed reactors.
NANOSCALE ADVANCES
(2023)
Article
Chemistry, Multidisciplinary
Sangjun Kang, Di Wang, Arnaud Caron, Christian Minnert, Karsten Durst, Christian Kuebel, Xiaoke Mu
Summary: Scanning/transmission electron microscopy (S/TEM) techniques have been used to analyze shear bands in metallic glasses for decades in order to improve their mechanical properties. However, conventional S/TEM lacks the ability to directly characterize the local strain and atomic structure of amorphous materials. In this study, 4-dimensional-STEM (4D-STEM) is applied to directly map and correlate the local strain and atomic structure at the nanometer scale in deformed metallic glasses. The results provide a new understanding of the formation of shear bands in metallic glasses.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Jasmin-Clara Burger, Sebastian Gutsch, Vanessa Wollersen, Di Wang, Bjorn Christian, Zhe Fu, Oliver Ambacher, Christian Kubel, Margit Zacharias
Summary: SnO2 nanowires were grown on r-plane sapphire substrates and characterized by scanning electron microscopy and atomic force microscopy, which revealed their highly oriented growth towards the substrate edges. High-resolution transmission electron microscopy and strain mapping were used to analyze the crystallographic alignment and defect distribution within the nanowire cross section. The findings were compared to freestanding SnO2 nanowires and SnO2 thin films on sapphire substrates.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Applied
J. Proff, M. Mail, A. Lindner, A. Scheuer, M. Bendrich, E. Quinet, A. Schuler, T. Scherer, C. Kuebel, M. Votsmeier
Summary: The diffusivity in the upper Cu-Chabazite layer of a dual layer ammonia oxidation catalyst with a lower Pt layer was investigated using FIB-SEM and CO oxidation measurements. FIB-SEM data showed an estimated effective diffusivity of 0.31, while CO oxidation experiments yielded a lower value of 0.11. NH3 oxidation experiments confirmed the effectiveness of the CO-derived diffusivity coefficient. The reason for the discrepancy between FIB-SEM and CO oxidation results requires further investigation.
TOPICS IN CATALYSIS
(2023)
Article
Multidisciplinary Sciences
Kai Wang, Weibo Hua, Xiaohui Huang, David Stenzel, Junbo Wang, Ziming Ding, Yanyan Cui, Qingsong Wang, Helmut Ehrenberg, Ben Breitung, Christian Kuebel, Xiaoke Mu
Summary: High entropy oxides (HEOs) with chemically disordered multi-cation structure have attracted significant attention as negative electrode materials for batteries. However, the mechanisms behind their outstanding electrochemical performance and the so-called 'cocktail effect' have not been fully understood. In this study, the authors investigate the behavior of each element in the HEO Mg0.2Co0.2Ni0.2Cu0.2Zn0.2O during electrochemical reaction and connect it to the nanoscale structure, revealing the multi-cations synergy and explaining the 'cocktail effect'. The findings demonstrate the importance of elemental diversity in optimizing multi-cation electrode materials for batteries.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Antonio Gentile, Stefanie Arnold, Chiara Ferrara, Stefano Marchionna, Yushu Tang, Julia Maibach, Christian Kuebel, Volker Presser, Riccardo Ruffo
Summary: The use of composites with two-dimensional materials and conversion/alloying materials, such as SnO2, can improve the performance of lithium-ion batteries and overcome the mechanical instability issue. This study presents a 50/50 SnO2/Ti3C2Tz nanocomposite that demonstrates excellent cycling and rate performance. The synergistic behavior of the two components in the nanocomposite enables partial reversibility of the conversion reaction.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Mehrdad Jalali, Matthias Mail, Rossella Aversa, Christian Kubel
Summary: This paper introduces the MSLE ontology, a new ontology for Materials Science Laboratory Equipment, which aims to unify the description and guide the appropriate use of lab equipment. It integrates the Semantic Sensor Network (SSN) and the Material Vocabulary (MatVoc) into the MSLE core and utilizes the Simple Knowledge Organization System (SKOS) to represent the hierarchical structure of equipment terms. The development of the ontology involved collaboration with domain experts and focused on materials characterization devices.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Beatriz Mendoza-Sanchez, Enrique Samperio-Niembro, Oleksandr Dolotko, Thomas Bergfeldt, Christian Ku''bel, Michael Knapp, Christopher E. Shuck
Summary: This study comprehensively investigates the synthesis of MXene, with a specific focus on the properties of etched materials. Through different experimental conditions and various characterization techniques, it is found that the elemental composition, particle size, and crystal structure of the MAX precursor are critically relevant to the etching process and properties of etched materials. Additionally, XRD studies reveal the advantages of using a HF/HCl mix over only HF, in terms of crystal-structure-type of acid correlations.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Tobias Braun, Sirshendu Dinda, Guruprakash Karkera, Georgian Melinte, Thomas Diemant, Christian Kuebel, Maximilian Fichtner, Frank Pammer
Summary: The development of commercially viable fuel cells and metal-air batteries requires effective and cheap bifunctional catalysts for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). Multi-component Pt-Fe-Co-Ni nanoparticles on multi-walled carbon nanotubes (MWCNTs) synthesized by wet chemistry route show excellent ORR activity and promising OER activity, comparable to Pt/C or RuO2. The catalyst also has outstanding long-term stability in ORR and OER, indicating the significant effect of Pt substitution by transition metal (TM) and the formation of nanoparticles on catalytic performance.
Article
Chemistry, Physical
Ziming Ding, Yushu Tang, Till Ortmann, Janis Kevin Eckhardt, Yuting Dai, Marcus Rohnke, Georgian Melinte, Christian Heiliger, Juergen Janek, Christian Kuebel
Summary: This study investigates the influence of microstructure on sodium filament growth and ion transport in sodium-based all-solid-state batteries using polycrystalline Na-beta ''-alumina as a model material. In-situ transmission electron microscopy (TEM) measurements are combined with crystal orientation analysis to explore the relationship between microstructure, grain boundaries, and sodium filament growth. The study also validates the in-situ TEM analysis using post-mortem secondary ion mass spectrometer (SIMS) analysis.
ADVANCED ENERGY MATERIALS
(2023)
Article
Microscopy
Sangjun Kang, Di Wang, Christian Kuebel, Xiaoke Mu
Summary: Transmission electron microscopy is a valuable tool for assessing strain fields within materials. However, using thin specimens in TEM analysis can affect atomic configuration and deformation structure.
