Hohan Bae, Gyeong Duk Nam, Yeon Namgung, Kwangho Park, Jun-Young Park, José M. Serra, Jong Hoon Joo, Sun-Ju Song
This study focuses on mixed-conducting perovskite membranes for efficient oxygen supply, aiming to replace energy-intensive cryogenic distillation with a more practical alternative. A La and Nb co-doped BaCoO3−δ perovskite is introduced, Ba0.95La0.05Co0.8Fe0.12Nb0.08O3−δ (BLCFN) with a record-breaking oxygen permeation flux, surpassing all known single-phase perovskite membranes. To elucidate its superior membrane performance, the mass/charge transport properties and equilibrium bulk properties are investigated and quantitative indicators (DO = 5.8 × 10−6 cm2 s−1, kO = 1.0 × 10−4 cm s−1, σion = 0.93 S cm−1 at 900 °C) reveal fast diffusion and excellent surface gas-exchange kinetics. The oxygen permeability of 12.4 mL cm−2 min−1 and over 200 h of long-term stability is achieved in an air/He atmosphere at 900 °C. By presenting a material that demonstrates higher performance than Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF), currently known for its highest permeability, it is believed that this marks a significant step toward innovative performance enhancement of perovskite oxide-based membranes.
本研究的重点是用于高效供氧的混合导电包晶膜，旨在用一种更实用的替代品取代高能耗的低温蒸馏。本文介绍了一种镧和铌共掺杂的 BaCoO3-δ 包晶石--Ba0.95La0.05Co0.8Fe0.12Nb0.08O3-δ（BLCFN），其氧气渗透通量打破了记录，超过了所有已知的单相包晶石膜。为了阐明其卓越的膜性能，我们对其质量/电荷传输特性和平衡体积特性进行了研究，定量指标（DO = 5.8 × 10-6 cm2 s-1，kO = 1.0 × 10-4 cm s-1，σion = 0.93 S cm-1，900 °C）显示了快速扩散和出色的表面气体交换动力学。在 900 °C 的空气/He 环境中，氧气渗透率达到 12.4 mL cm-2 min-1，长期稳定性超过 200 小时。通过展示一种比目前以最高渗透性著称的 Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) 性能更高的材料，相信这标志着向创新性地提高基于过氧化物的膜的性能迈出了重要一步。
{"title":"Exceptional High-Performance Oxygen Transport Membrane and Comprehensive Study on Mass/Charge Transport Properties","authors":"Hohan Bae, Gyeong Duk Nam, Yeon Namgung, Kwangho Park, Jun-Young Park, José M. Serra, Jong Hoon Joo, Sun-Ju Song","doi":"10.1002/sstr.202400095","DOIUrl":"https://doi.org/10.1002/sstr.202400095","url":null,"abstract":"This study focuses on mixed-conducting perovskite membranes for efficient oxygen supply, aiming to replace energy-intensive cryogenic distillation with a more practical alternative. A La and Nb co-doped BaCoO<sub>3−<i>δ</i></sub> perovskite is introduced, Ba<sub>0.95</sub>La<sub>0.05</sub>Co<sub>0.8</sub>Fe<sub>0.12</sub>Nb<sub>0.08</sub>O<sub>3−<i>δ</i></sub> (BLCFN) with a record-breaking oxygen permeation flux, surpassing all known single-phase perovskite membranes. To elucidate its superior membrane performance, the mass/charge transport properties and equilibrium bulk properties are investigated and quantitative indicators (<i>D</i><sub>O</sub> = 5.8 × 10<sup>−6</sup> cm<sup>2</sup> s<sup>−1</sup>, <i>k</i><sub>O</sub> = 1.0 × 10<sup>−4</sup> cm s<sup>−1</sup>, <i>σ</i><sub>ion</sub> = 0.93 S cm<sup>−1</sup> at 900 °C) reveal fast diffusion and excellent surface gas-exchange kinetics. The oxygen permeability of 12.4 mL cm<sup>−2</sup> min<sup>−1</sup> and over 200 h of long-term stability is achieved in an air/He atmosphere at 900 °C. By presenting a material that demonstrates higher performance than Ba<sub>0.5</sub>Sr<sub>0.5</sub>Co<sub>0.8</sub>Fe<sub>0.2</sub>O<sub>3−<i>δ</i></sub> (BSCF), currently known for its highest permeability, it is believed that this marks a significant step toward innovative performance enhancement of perovskite oxide-based membranes.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141257501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Topological materials are currently considered excellent catalysts for heterogeneous processes because of their surface metallic states and excellent carrier mobility. This work will show that cubic palladium bronze LaPd3S4 is an ideal topological material with multifold fermions, Fermi arcs on the (001) surface, and high catalytic performance for electrochemical hydrogen evolution reactions (HER). A direct correlation has been discovered between the position of the multifold fermions (related to the Fermi level) and Gibbs free energy (ΔGH*). Moreover, by applying the vertical electric field and uniaxial strain to the LaPd3S4, the multifold fermions disappear, and the |ΔGH*| increases, weakening the HER activity. This correlation establishes a clear connection between increased catalytic performance and topological states and fully elucidates the underlying process in topological catalysis.
拓扑材料因其表面金属态和出色的载流子迁移率，目前被认为是异相过程的极佳催化剂。这项研究将表明，立方钯青铜 LaPd3S4 是一种理想的拓扑材料，具有多折费米子、（001）表面费米弧和高催化性能，可用于电化学氢进化反应（HER）。研究发现，多折费米子的位置（与费米级有关）与吉布斯自由能（ΔGH*）之间存在直接关联。此外，通过对 LaPd3S4 施加垂直电场和单轴应变，多折费米子消失，|ΔGH*|增加，从而削弱了 HER 活性。这种相关性在催化性能的提高与拓扑态之间建立了明确的联系，并充分阐明了拓扑催化的基本过程。
{"title":"Multifold Fermions Boosted Hydrogen Evolution Reaction Catalysis in Cubic Palladium Bronze LaPd3S4","authors":"Yang Li, Jialin Gong, Xiaotian Wang","doi":"10.1002/sstr.202400175","DOIUrl":"https://doi.org/10.1002/sstr.202400175","url":null,"abstract":"Topological materials are currently considered excellent catalysts for heterogeneous processes because of their surface metallic states and excellent carrier mobility. This work will show that cubic palladium bronze LaPd<sub>3</sub>S<sub>4</sub> is an ideal topological material with multifold fermions, Fermi arcs on the (001) surface, and high catalytic performance for electrochemical hydrogen evolution reactions (HER). A direct correlation has been discovered between the position of the multifold fermions (related to the Fermi level) and Gibbs free energy (Δ<i>G</i><sub>H*</sub>). Moreover, by applying the vertical electric field and uniaxial strain to the LaPd<sub>3</sub>S<sub>4</sub>, the multifold fermions disappear, and the |Δ<i>G</i><sub>H*</sub>| increases, weakening the HER activity. This correlation establishes a clear connection between increased catalytic performance and topological states and fully elucidates the underlying process in topological catalysis.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141259823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiaxin Rui, Meng Chen, Tingting Wu, Xuzhi Shi, Wei Lu, Meng Dang, Xiaolin Han, Ning Wang, Yuru Wang, Xiaodan Su, Zhaogang Teng
3D superstructures (3DSs) have attracted increasing interest because of the collective synergistic effects of individual building units, but their customization relies on tedious multistep strategy or high-end nanofabrication technology. Herein, for the first time, a facile block copolymer micelle-mediated anisotropic growth approach is reported to fabricate gold 3DSs consisting of tunable and intersecting lamellae with sawtooth-like edges. The preparation of the 3DSs depends on the mediation of reduction kinetics of gold precursors and adsorption of block copolymer micelles on gold crystal surfaces using disulfiram as ligands. The thickness of lamellae in the 3DSs is controllable from ≈21 to 102 nm by adjusting the weight fraction of the micellar hydrophobicity blocks and the composed lamellar number is regulated from ≈3 to ≈30. Additional morphologies, such as a dendritic mesoporous structure and meatball-like shapes, are obtained through controlling the extent of micelle swelling. Finite-difference time-domain simulations demonstrate that the unique 3DSs of gold lamellae with sawtooth-like edges form abundant hotspots giving rise to surface-enhanced Raman scattering (SERS). The 3DSs exhibit strong electromagnetic field enhancement and excellent performance as SERS substrates for detecting 4-mercaptobenzoic acid.
{"title":"3D Superstructures Consisting of Intersecting Gold Lamellae Formed by a Micelle-Mediated Anisotropic Growth Approach","authors":"Jiaxin Rui, Meng Chen, Tingting Wu, Xuzhi Shi, Wei Lu, Meng Dang, Xiaolin Han, Ning Wang, Yuru Wang, Xiaodan Su, Zhaogang Teng","doi":"10.1002/sstr.202400072","DOIUrl":"https://doi.org/10.1002/sstr.202400072","url":null,"abstract":"3D superstructures (3DSs) have attracted increasing interest because of the collective synergistic effects of individual building units, but their customization relies on tedious multistep strategy or high-end nanofabrication technology. Herein, for the first time, a facile block copolymer micelle-mediated anisotropic growth approach is reported to fabricate gold 3DSs consisting of tunable and intersecting lamellae with sawtooth-like edges. The preparation of the 3DSs depends on the mediation of reduction kinetics of gold precursors and adsorption of block copolymer micelles on gold crystal surfaces using disulfiram as ligands. The thickness of lamellae in the 3DSs is controllable from ≈21 to 102 nm by adjusting the weight fraction of the micellar hydrophobicity blocks and the composed lamellar number is regulated from ≈3 to ≈30. Additional morphologies, such as a dendritic mesoporous structure and meatball-like shapes, are obtained through controlling the extent of micelle swelling. Finite-difference time-domain simulations demonstrate that the unique 3DSs of gold lamellae with sawtooth-like edges form abundant hotspots giving rise to surface-enhanced Raman scattering (SERS). The 3DSs exhibit strong electromagnetic field enhancement and excellent performance as SERS substrates for detecting 4-mercaptobenzoic acid.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141173024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Diogo V. Saraiva, Steven N. Remiëns, Ethan I. L. Jull, Ivo R. Vermaire, Lisa Tran
Most paints contain pigments that absorb light and fade over time. A robust alternative can be found in nature, where structural coloration arises from the interference of light with submicron features. Plant-derived, cellulose nanocrystals (CNCs) mimic these features by self-assembling into a cholesteric liquid crystal that exhibits structural coloration when dried. While much research has been done on CNCs in aqueous solutions, less is known about transferring CNCs to apolar solvents that are widely employed in paints. This study uses a common surfactant in agricultural and industrial products to suspend CNCs in toluene . Surprisingly, a stable liquid crystal phase is formed within hours, even with concentrations of up to 50 wt%. Evaporating the apolar CNC suspensions results in photonic films with peak wavelengths ranging from 660 to 920 nm. The resulting flexible films have variable mechanical properties with surfactant content, allowing for an optical response with applied force. The films also act as humidity sensors, with increasing relative humidity swelling the films, yielding a redshift in the reflected wavelength. With the addition of a single surfactant, CNCs can be made compatible with existing production methods of industrial coatings, while improving the strength and responsiveness of structurally colored films to external stimuli.
{"title":"Flexible, Photonic Films of Surfactant-Functionalized Cellulose Nanocrystals for Pressure and Humidity Sensing","authors":"Diogo V. Saraiva, Steven N. Remiëns, Ethan I. L. Jull, Ivo R. Vermaire, Lisa Tran","doi":"10.1002/sstr.202400104","DOIUrl":"https://doi.org/10.1002/sstr.202400104","url":null,"abstract":"Most paints contain pigments that absorb light and fade over time. A robust alternative can be found in nature, where structural coloration arises from the interference of light with submicron features. Plant-derived, cellulose nanocrystals (CNCs) mimic these features by self-assembling into a cholesteric liquid crystal that exhibits structural coloration when dried. While much research has been done on CNCs in aqueous solutions, less is known about transferring CNCs to apolar solvents that are widely employed in paints. This study uses a common surfactant in agricultural and industrial products to suspend CNCs in toluene . Surprisingly, a stable liquid crystal phase is formed within hours, even with concentrations of up to 50 wt%. Evaporating the apolar CNC suspensions results in photonic films with peak wavelengths ranging from 660 to 920 nm. The resulting flexible films have variable mechanical properties with surfactant content, allowing for an optical response with applied force. The films also act as humidity sensors, with increasing relative humidity swelling the films, yielding a redshift in the reflected wavelength. With the addition of a single surfactant, CNCs can be made compatible with existing production methods of industrial coatings, while improving the strength and responsiveness of structurally colored films to external stimuli.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141172914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Near‐infrared (NIR) phosphors have been widely used in biomedical applications based on their deep tissue penetration. However, the lack of blue‐pumped NIR phosphors with emission ranges beyond 1000 nm has greatly limited the development of NIR phosphor‐converted light‐emitting diodes (pc‐LEDs). Herein, a facile way to boost the luminescence efficiency and thermal stability by introducing the promoters of Ce3+ and Na+ into Nd3+‐doped SrS NIR phosphor is demonstrated, thus achieving light emitting at 850–1500 nm with a peak wavelength of ≈1070 nm. Through sensitization by the allowed 4f → 5d transition of Ce3+, the SrS: Nd3+ phosphors are excitable by using a commercial blue LED, attributing to the effective energy transfer between Nd3+ and Ce3+. Besides, the structural analysis and density functional theory calculations reveal the lattice distortion mechanism and geometry of doping ions contributed to the weakened thermal quenching effect and the increasing of internal quantum efficiency. The optimized NIR phosphor luminescence intensity remains at 91.8% of the initial intensity at 393 K, and the internal quantum efficiency increases to 42.8% from 31.7% of the sample without Na+ doping. The present exploration of Nd3+‐doped NIR phosphors will provide a reference for designing NIR pc‐LEDs with enhanced properties.
{"title":"Enabling Highly Efficient Neodymium Luminescence for Near‐Infrared Phosphor‐Converted Light‐Emitting Diode Applications","authors":"Kaina Wang, Jipeng Fu, Hongliang Dong, Bingyu Huang, Jinru Liu, Long Tian, Jing Feng, Chunzhen Yang, Chenjie Lou, Ligang Xu, Tianyi Sun, Huajie Luo, Shiqing Xu, Guowei Yin, Hongjie Zhang, Mingxue Tang","doi":"10.1002/sstr.202400092","DOIUrl":"https://doi.org/10.1002/sstr.202400092","url":null,"abstract":"Near‐infrared (NIR) phosphors have been widely used in biomedical applications based on their deep tissue penetration. However, the lack of blue‐pumped NIR phosphors with emission ranges beyond 1000 nm has greatly limited the development of NIR phosphor‐converted light‐emitting diodes (pc‐LEDs). Herein, a facile way to boost the luminescence efficiency and thermal stability by introducing the promoters of Ce3+ and Na+ into Nd3+‐doped SrS NIR phosphor is demonstrated, thus achieving light emitting at 850–1500 nm with a peak wavelength of ≈1070 nm. Through sensitization by the allowed 4f → 5d transition of Ce3+, the SrS: Nd3+ phosphors are excitable by using a commercial blue LED, attributing to the effective energy transfer between Nd3+ and Ce3+. Besides, the structural analysis and density functional theory calculations reveal the lattice distortion mechanism and geometry of doping ions contributed to the weakened thermal quenching effect and the increasing of internal quantum efficiency. The optimized NIR phosphor luminescence intensity remains at 91.8% of the initial intensity at 393 K, and the internal quantum efficiency increases to 42.8% from 31.7% of the sample without Na+ doping. The present exploration of Nd3+‐doped NIR phosphors will provide a reference for designing NIR pc‐LEDs with enhanced properties.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"20 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141104932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Graf, D. Pluta, Adrian Hannebauer, Jakob Schlenkrich, N. Bigall
Cadmium chalcogenide nanoplatelets (NPLs) are not only known due to their unique optical properties but also because of their ability to self‐assemble into stacks with new collective properties. Only recently, a stacking process in an aqueous medium has been demonstrated, which opens up possible applications and methods such as gelation. Nanoparticle‐based aerogels gain a lot of attention due to their high relative surface areas and porosity and thus, high potential for catalytic applications. Herein, the positive properties of aerogels to the NPL‐stack system by cryoaerogelation of destabilized NPL dispersions are introduced. After the addition of an antisolvent to initiate the stacking, the dispersion is flash‐frozen with liquid nitrogen and freeze‐dried. By this method, porous cryoaerogel networks result in high surface areas and retained stacking of the NPLs. The formed stack‐gels are investigated by electron microscopy and physisorption measurements. Optical and photoelectrochemical measurements verify the charge carrier transport within the stack‐gel network.
{"title":"Synthesis of Porous Connected Cryoaerogel Networks from Cadmium Chalcogenide Nanoplatelet Stacks","authors":"R. Graf, D. Pluta, Adrian Hannebauer, Jakob Schlenkrich, N. Bigall","doi":"10.1002/sstr.202300554","DOIUrl":"https://doi.org/10.1002/sstr.202300554","url":null,"abstract":"Cadmium chalcogenide nanoplatelets (NPLs) are not only known due to their unique optical properties but also because of their ability to self‐assemble into stacks with new collective properties. Only recently, a stacking process in an aqueous medium has been demonstrated, which opens up possible applications and methods such as gelation. Nanoparticle‐based aerogels gain a lot of attention due to their high relative surface areas and porosity and thus, high potential for catalytic applications. Herein, the positive properties of aerogels to the NPL‐stack system by cryoaerogelation of destabilized NPL dispersions are introduced. After the addition of an antisolvent to initiate the stacking, the dispersion is flash‐frozen with liquid nitrogen and freeze‐dried. By this method, porous cryoaerogel networks result in high surface areas and retained stacking of the NPLs. The formed stack‐gels are investigated by electron microscopy and physisorption measurements. Optical and photoelectrochemical measurements verify the charge carrier transport within the stack‐gel network.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"48 34","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141102961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Chesnyak, Srdjan Stavrić, M. Panighel, Daniele Povoledo, S. del Puppo, M. Peressi, Giovanni Comelli, C. Africh
To improve reactivity and achieve a higher material efficiency, catalysts are often used in the form of clusters with nanometer dimensions, down to single atoms. Since the corresponding properties are highly structure‐dependent, a suitable support is thus required to ensure cluster stability during operating conditions. Herein, an efficient method to stabilize cobalt nanoclusters on graphene grown on nickel substrates, exploiting the anchoring effect of nickel atoms incorporated in the carbon network is presented. The anchored nanoclusters are studied by in situ variable temperature scanning tunneling microscopy at different temperatures and upon gas exposure. Cluster stability upon annealing up to 200 °C and upon CO exposure at least up to 1 × 10−6 mbar CO partial pressure is demonstrated. Moreover, the dimensions of the cobalt nanoclusters remain surprisingly small (<3 nm diameter) with a narrow size distribution. Density functional theory calculations demonstrate that the interplay between the low diffusion barrier on graphene on nickel and the strong anchoring effect of the nickel atoms leads to the increased stability and size selectivity of these clusters. This anchoring technique is expected to be applicable also to other cases, with clear advantages for transition metals that are usually difficult to stabilize.
{"title":"Exceptionally Stable Cobalt Nanoclusters on Functionalized Graphene","authors":"V. Chesnyak, Srdjan Stavrić, M. Panighel, Daniele Povoledo, S. del Puppo, M. Peressi, Giovanni Comelli, C. Africh","doi":"10.1002/sstr.202400055","DOIUrl":"https://doi.org/10.1002/sstr.202400055","url":null,"abstract":"\u0000To improve reactivity and achieve a higher material efficiency, catalysts are often used in the form of clusters with nanometer dimensions, down to single atoms. Since the corresponding properties are highly structure‐dependent, a suitable support is thus required to ensure cluster stability during operating conditions. Herein, an efficient method to stabilize cobalt nanoclusters on graphene grown on nickel substrates, exploiting the anchoring effect of nickel atoms incorporated in the carbon network is presented. The anchored nanoclusters are studied by in situ variable temperature scanning tunneling microscopy at different temperatures and upon gas exposure. Cluster stability upon annealing up to 200 °C and upon CO exposure at least up to 1 × 10−6 mbar CO partial pressure is demonstrated. Moreover, the dimensions of the cobalt nanoclusters remain surprisingly small (<3 nm diameter) with a narrow size distribution. Density functional theory calculations demonstrate that the interplay between the low diffusion barrier on graphene on nickel and the strong anchoring effect of the nickel atoms leads to the increased stability and size selectivity of these clusters. This anchoring technique is expected to be applicable also to other cases, with clear advantages for transition metals that are usually difficult to stabilize.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"65 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141105939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Brognara, Ankush Kashiwar, C. Jung, Xukai Zhang, Ali Ahmadian, N. Gauquelin, J. Verbeeck, Philippe Djemia, Damien Faurie, G. Dehm, H. Idrissi, J. P. Best, M. Ghidelli
The design of high‐performance structural thin films consistently seeks to achieve a delicate equilibrium by balancing outstanding mechanical properties like yield strength, ductility, and substrate adhesion, which are often mutually exclusive. Metallic glasses (MGs) with their amorphous structure have superior strength, but usually poor ductility with catastrophic failure induced by shear bands (SBs) formation. Herein, we introduce an innovative approach by synthesizing MGs characterized by large and tunable mechanical properties, pioneering a nanoengineering design based on the control of nanoscale chemical/structural heterogeneities. This is realized through a simplified model Zr24Cu76/Zr61Cu39, fully amorphous nanocomposite with controlled nanoscale periodicity (Λ, from 400 down to 5 nm), local chemistry, and glass–glass interfaces, while focusing in‐depth on the SB nucleation/propagation processes. The nanolaminates enable a fine control of the mechanical properties, and an onset of crack formation/percolation (>1.9 and 3.3%, respectively) far above the monolithic counterparts. Moreover, we show that SB propagation induces large chemical intermixing, enabling a brittle‐to‐ductile transition when Λ ≤ 50 nm, reaching remarkably large plastic deformation of 16% in compression and yield strength ≈2 GPa. Overall, the nanoengineered control of local heterogeneities leads to ultimate and tunable mechanical properties opening up a new approach for strong and ductile materials.
{"title":"Tailoring Mechanical Properties and Shear Band Propagation in ZrCu Metallic Glass Nanolaminates Through Chemical Heterogeneities and Interface Density","authors":"A. Brognara, Ankush Kashiwar, C. Jung, Xukai Zhang, Ali Ahmadian, N. Gauquelin, J. Verbeeck, Philippe Djemia, Damien Faurie, G. Dehm, H. Idrissi, J. P. Best, M. Ghidelli","doi":"10.1002/sstr.202400011","DOIUrl":"https://doi.org/10.1002/sstr.202400011","url":null,"abstract":"The design of high‐performance structural thin films consistently seeks to achieve a delicate equilibrium by balancing outstanding mechanical properties like yield strength, ductility, and substrate adhesion, which are often mutually exclusive. Metallic glasses (MGs) with their amorphous structure have superior strength, but usually poor ductility with catastrophic failure induced by shear bands (SBs) formation. Herein, we introduce an innovative approach by synthesizing MGs characterized by large and tunable mechanical properties, pioneering a nanoengineering design based on the control of nanoscale chemical/structural heterogeneities. This is realized through a simplified model Zr24Cu76/Zr61Cu39, fully amorphous nanocomposite with controlled nanoscale periodicity (Λ, from 400 down to 5 nm), local chemistry, and glass–glass interfaces, while focusing in‐depth on the SB nucleation/propagation processes. The nanolaminates enable a fine control of the mechanical properties, and an onset of crack formation/percolation (>1.9 and 3.3%, respectively) far above the monolithic counterparts. Moreover, we show that SB propagation induces large chemical intermixing, enabling a brittle‐to‐ductile transition when Λ ≤ 50 nm, reaching remarkably large plastic deformation of 16% in compression and yield strength ≈2 GPa. Overall, the nanoengineered control of local heterogeneities leads to ultimate and tunable mechanical properties opening up a new approach for strong and ductile materials.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"35 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141123477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yifeng Shi, Yifan Zheng, Xun Xiao, Yan Li, Dianfu Feng, Guodong Zhang, Yang Zhang, Tao Li, Yuchuan Shao
Ion migration presents a formidable obstacle to the stability and performance of perovskite solar cells (PSCs), hindering their progress toward commercial feasibility. Herein, the degradation mechanism of PSCs caused by iodide ion migration, which leads to abnormal changes in photoluminescence transients at the buried interface of perovskite films, is investigated. In light of this problem, a novel strategy is proposed to mitigate ion migration by introducing poly(2‐vinylnaphthalene) into poly[bis(4‐phenyl)(2,4,6‐trimethylphenyl)amine] as the hole transport layer with improved ion‐blocking capability. Consequently, this layer effectively reduces defect concentration, suppresses ion migration, and modulates energy level alignment, leading to an impressive efficiency exceeding 23% for doctor‐bladed FAPbI3 PSCs. Moreover, the corresponding unencapsulated devices demonstrate remarkable durability, maintaining over 80% of their initial value after undergoing rigorous stress tests in accordance with the International Electrotechnical Commission 61215 standard for temperature, humidity, and illumination. These tests include 1000 h of thermal cycling and a long‐term operational test lasting 600 h under maximum power point tracking.
{"title":"Improving Thermal Stability of Perovskite Solar Cells by Suppressing Ion Migration","authors":"Yifeng Shi, Yifan Zheng, Xun Xiao, Yan Li, Dianfu Feng, Guodong Zhang, Yang Zhang, Tao Li, Yuchuan Shao","doi":"10.1002/sstr.202400132","DOIUrl":"https://doi.org/10.1002/sstr.202400132","url":null,"abstract":"Ion migration presents a formidable obstacle to the stability and performance of perovskite solar cells (PSCs), hindering their progress toward commercial feasibility. Herein, the degradation mechanism of PSCs caused by iodide ion migration, which leads to abnormal changes in photoluminescence transients at the buried interface of perovskite films, is investigated. In light of this problem, a novel strategy is proposed to mitigate ion migration by introducing poly(2‐vinylnaphthalene) into poly[bis(4‐phenyl)(2,4,6‐trimethylphenyl)amine] as the hole transport layer with improved ion‐blocking capability. Consequently, this layer effectively reduces defect concentration, suppresses ion migration, and modulates energy level alignment, leading to an impressive efficiency exceeding 23% for doctor‐bladed FAPbI3 PSCs. Moreover, the corresponding unencapsulated devices demonstrate remarkable durability, maintaining over 80% of their initial value after undergoing rigorous stress tests in accordance with the International Electrotechnical Commission 61215 standard for temperature, humidity, and illumination. These tests include 1000 h of thermal cycling and a long‐term operational test lasting 600 h under maximum power point tracking.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"28 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140969776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhuotong Sun, Ziyi Yuan, Ming Xiao, Simon M. Fairclough, Atif Jan, Giuliana Di Martino, Caterina Ducati, N. Strkalj, Judith L. MacManus‐Driscoll
As Si electronics hits fundamental performance limits, oxide integration emerges as a solution to augment the next generation of electronic and optical devices. Specifically, oxide perovskites provide diverse functionalities with a potential to create, tune, and combine emergent phenomena at interfaces. High‐level crystalline order is needed to realize these functionalities, often achieved through epitaxy. However, large‐scale implementation in consumer devices faces challenges due to the need for high‐temperature deposition in complex vacuum systems. Herein, this challenge is addressed using atmospheric pressure spatial chemical vapor deposition, a thin‐film fabrication technique that can rapidly produce uniform films at sub‐400 °C temperatures under atmospheric conditions over ≈cm2 areas. Thus, the deposition of epitaxial perovskite tungsten trioxide, WO3, thin films is demonstrated at a rate of 5 nm min−2 on single‐crystal substrates at 350 °C in open‐air conditions enabling a high‐throughput process. The resulting films exhibit crystallographic and electronic properties comparable to vacuum‐based growth above 500 °C. The high‐quality epitaxy is attributed to the energetics of the exothermic decomposition reaction of the W[CO]6 precursors combined with the stabilization of a hot zone near the substrate surface. From this work, the way can be paved for low‐temperature atmospheric‐pressure epitaxy of a wide range of other perovskite thin films.
随着硅电子器件的基本性能达到极限，氧化物集成成为增强下一代电子和光学器件的解决方案。具体来说，氧化物包晶提供了多种功能，有可能在界面上创造、调整和组合新出现的现象。要实现这些功能，需要较高的晶序，通常通过外延来实现。然而，由于需要在复杂的真空系统中进行高温沉积，消费类设备的大规模应用面临着挑战。在此，我们采用大气压空间化学气相沉积技术来应对这一挑战，这种薄膜制造技术可在大气条件下以低于 400 °C 的温度在 ≈cm2 的面积上快速生成均匀的薄膜。因此，在 350 °C 的露天条件下，以 5 nm min-2 的速度在单晶基底上沉积外延包晶三氧化钨（WO3）薄膜，实现了高通量工艺。所得薄膜的晶体学和电子特性可与 500 °C 以上的真空生长相媲美。高质量的外延归功于 W[CO]6 前驱体放热分解反应的能量学原理，以及基底表面附近热区的稳定。从这项工作出发，可以为其他各种包晶体薄膜的低温常压外延铺平道路。
{"title":"Low‐Temperature Epitaxy of Perovskite WO3 Thin Films under Atmospheric Conditions","authors":"Zhuotong Sun, Ziyi Yuan, Ming Xiao, Simon M. Fairclough, Atif Jan, Giuliana Di Martino, Caterina Ducati, N. Strkalj, Judith L. MacManus‐Driscoll","doi":"10.1002/sstr.202400089","DOIUrl":"https://doi.org/10.1002/sstr.202400089","url":null,"abstract":"As Si electronics hits fundamental performance limits, oxide integration emerges as a solution to augment the next generation of electronic and optical devices. Specifically, oxide perovskites provide diverse functionalities with a potential to create, tune, and combine emergent phenomena at interfaces. High‐level crystalline order is needed to realize these functionalities, often achieved through epitaxy. However, large‐scale implementation in consumer devices faces challenges due to the need for high‐temperature deposition in complex vacuum systems. Herein, this challenge is addressed using atmospheric pressure spatial chemical vapor deposition, a thin‐film fabrication technique that can rapidly produce uniform films at sub‐400 °C temperatures under atmospheric conditions over ≈cm2 areas. Thus, the deposition of epitaxial perovskite tungsten trioxide, WO3, thin films is demonstrated at a rate of 5 nm min−2 on single‐crystal substrates at 350 °C in open‐air conditions enabling a high‐throughput process. The resulting films exhibit crystallographic and electronic properties comparable to vacuum‐based growth above 500 °C. The high‐quality epitaxy is attributed to the energetics of the exothermic decomposition reaction of the W[CO]6 precursors combined with the stabilization of a hot zone near the substrate surface. From this work, the way can be paved for low‐temperature atmospheric‐pressure epitaxy of a wide range of other perovskite thin films.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140966674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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