Pub Date : 2024-09-16DOI: 10.1038/s43246-024-00632-y
Manisha Rajput, Sameer Kumar Mallik, Sagnik Chatterjee, Ashutosh Shukla, Sooyeon Hwang, Satyaprakash Sahoo, G. V. Pavan Kumar, Atikur Rahman
Two-dimensional transition metal dichalcogenides (TMDs)-based memristors are promising candidates for realizing artificial synapses in next-generation computing. However, practical implementation faces several challenges, such as high non-linearity and asymmetry in synaptic weight updates, limited dynamic range, and cycle-to-cycle variability. Here, utilizing optimal-power argon plasma treatment, we significantly enhance the performance matrix of memristors fabricated from monolayer MoS2. Our approach not only improves linearity and symmetry in synaptic weight updates but also increases the number of available synaptic weight updates and enhances Spike-Time Dependent Plasticity. Notably, it broadens the switching ratio by two orders, minimizes cycle-to-cycle variability, reduces non-linear factors, and achieves an energy consumption of ~30 fJ per synaptic event. Implementation of these enhancements is demonstrated through Artificial Neural Network simulations, yielding a learning accuracy of ~97% on the MNIST hand-written digits dataset. Our findings underscore the significance of defect engineering as a powerful tool in advancing the synaptic functionality of memristors. Memristors based on 2D materials are promising candidates for realizing artificial synapses in next-generation computing. Here, utilizing optimal-power argon plasma treatment, the authors enhance the performance of memristors fabricated from monolayer MoS2, reducing non-linearity and asymmetry in synaptic weight updates and minimizing cycle-to-cycle variability.
{"title":"Defect-engineered monolayer MoS2 with enhanced memristive and synaptic functionality for neuromorphic computing","authors":"Manisha Rajput, Sameer Kumar Mallik, Sagnik Chatterjee, Ashutosh Shukla, Sooyeon Hwang, Satyaprakash Sahoo, G. V. Pavan Kumar, Atikur Rahman","doi":"10.1038/s43246-024-00632-y","DOIUrl":"10.1038/s43246-024-00632-y","url":null,"abstract":"Two-dimensional transition metal dichalcogenides (TMDs)-based memristors are promising candidates for realizing artificial synapses in next-generation computing. However, practical implementation faces several challenges, such as high non-linearity and asymmetry in synaptic weight updates, limited dynamic range, and cycle-to-cycle variability. Here, utilizing optimal-power argon plasma treatment, we significantly enhance the performance matrix of memristors fabricated from monolayer MoS2. Our approach not only improves linearity and symmetry in synaptic weight updates but also increases the number of available synaptic weight updates and enhances Spike-Time Dependent Plasticity. Notably, it broadens the switching ratio by two orders, minimizes cycle-to-cycle variability, reduces non-linear factors, and achieves an energy consumption of ~30 fJ per synaptic event. Implementation of these enhancements is demonstrated through Artificial Neural Network simulations, yielding a learning accuracy of ~97% on the MNIST hand-written digits dataset. Our findings underscore the significance of defect engineering as a powerful tool in advancing the synaptic functionality of memristors. Memristors based on 2D materials are promising candidates for realizing artificial synapses in next-generation computing. Here, utilizing optimal-power argon plasma treatment, the authors enhance the performance of memristors fabricated from monolayer MoS2, reducing non-linearity and asymmetry in synaptic weight updates and minimizing cycle-to-cycle variability.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00632-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142234031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-14DOI: 10.1038/s43246-024-00633-x
Oleg Makarovsky, Richard J. A. Hill, Tin S. Cheng, Alex Summerfield, Takeshi Taniguchi, Kenji Watanabe, Christopher J. Mellor, Amalia Patanè, Laurence Eaves, Sergei V. Novikov, Peter H. Beton
Graphene placed on hexagonal boron nitride (hBN) has received significant interest due to its excellent electrical performance and physics phenomena, such as superlattice Dirac points. Direct molecular beam epitaxy growth of graphene on hBN offers an alternative fabrication route for hBN/graphene devices. Here, we investigate the electronic transport of moiré field effect transistors (FETs) in which the conducting channel is monolayer graphene grown on hexagonal boron nitride by high temperature molecular beam epitaxy (HT-MBE). Alignment between hBN and HT-MBE graphene crystal lattices gives rise to a moiré-fringed hexagonal superlattice pattern. Its electronic band structure takes the form of a “Hofstadter butterfly”. When a strong magnetic field B is applied perpendicular to the graphene layer, the electrical conductance displays magneto-oscillations, periodic in B−1, over a wide range of gate voltages and temperatures up to 350 K. We attribute this behaviour to the quantisation of electronic charge and magnetic flux within each unit cell of the superlattice, which gives rise to so-called Brown-Zak oscillations, previously reported only in high-mobility exfoliated graphene. Thus, this HT-MBE graphene/hBN heterostructure provides a platform for observation of room temperature quantum effects and device applications. Moiré field-effect transistors based on graphene/hexagonal boron nitride heterostructures are promising for their high room-temperature carrier mobilities and magnetotransport properties. Here, high-temperature molecular beam epitaxy growth of graphene/hBN gives rise to a moiré-fringed hexagonal superlattice with Hofstadter butterfly electronic band structure and quantum magneto-oscillations above room temperature.
置于六方氮化硼（hBN）上的石墨烯因其优异的电气性能和超晶格狄拉克点等物理现象而备受关注。石墨烯在六方氮化硼上的直接分子束外延生长为六方氮化硼/石墨烯器件的制造提供了另一种途径。在这里，我们研究了摩尔场效应晶体管（FET）的电子传输，其中导电通道是通过高温分子束外延（HT-MBE）生长在六方氮化硼上的单层石墨烯。氮化硼和 HT-MBE 石墨烯晶格之间的排列产生了摩尔边六边形超晶格图案。其电子能带结构呈 "霍夫斯塔特蝴蝶 "状。当施加垂直于石墨烯层的强磁场 B 时，电导率在广泛的栅极电压和高达 350 K 的温度范围内显示出以 B-1 为周期的磁振荡。我们将这种行为归因于超晶格每个单元格内的电子电荷和磁通量的量化，从而产生了所谓的布朗-扎克振荡，这种振荡以前只在高迁移率剥离石墨烯中报道过。因此，这种 HT-MBE 石墨烯/hBN 异质结构为观察室温量子效应和器件应用提供了一个平台。基于石墨烯/六方氮化硼异质结构的莫伊里场效应晶体管具有很高的室温载流子迁移率和磁传输特性，因此前景广阔。在这里，石墨烯/六方氮化硼的高温分子束外延生长产生了具有霍夫施塔特蝶形电子能带结构和室温以上量子磁振荡的摩尔边六方超晶格。
{"title":"High-temperature Brown-Zak oscillations in graphene/hBN moiré field effect transistor fabricated using molecular beam epitaxy","authors":"Oleg Makarovsky, Richard J. A. Hill, Tin S. Cheng, Alex Summerfield, Takeshi Taniguchi, Kenji Watanabe, Christopher J. Mellor, Amalia Patanè, Laurence Eaves, Sergei V. Novikov, Peter H. Beton","doi":"10.1038/s43246-024-00633-x","DOIUrl":"10.1038/s43246-024-00633-x","url":null,"abstract":"Graphene placed on hexagonal boron nitride (hBN) has received significant interest due to its excellent electrical performance and physics phenomena, such as superlattice Dirac points. Direct molecular beam epitaxy growth of graphene on hBN offers an alternative fabrication route for hBN/graphene devices. Here, we investigate the electronic transport of moiré field effect transistors (FETs) in which the conducting channel is monolayer graphene grown on hexagonal boron nitride by high temperature molecular beam epitaxy (HT-MBE). Alignment between hBN and HT-MBE graphene crystal lattices gives rise to a moiré-fringed hexagonal superlattice pattern. Its electronic band structure takes the form of a “Hofstadter butterfly”. When a strong magnetic field B is applied perpendicular to the graphene layer, the electrical conductance displays magneto-oscillations, periodic in B−1, over a wide range of gate voltages and temperatures up to 350 K. We attribute this behaviour to the quantisation of electronic charge and magnetic flux within each unit cell of the superlattice, which gives rise to so-called Brown-Zak oscillations, previously reported only in high-mobility exfoliated graphene. Thus, this HT-MBE graphene/hBN heterostructure provides a platform for observation of room temperature quantum effects and device applications. Moiré field-effect transistors based on graphene/hexagonal boron nitride heterostructures are promising for their high room-temperature carrier mobilities and magnetotransport properties. Here, high-temperature molecular beam epitaxy growth of graphene/hBN gives rise to a moiré-fringed hexagonal superlattice with Hofstadter butterfly electronic band structure and quantum magneto-oscillations above room temperature.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00633-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142234035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Most of the van der Waals homo- and hetero-junctions of group VIB two-dimensional (2D) transition-metal dichalcogenides (TMDs; MoS2, WS2, MoSe2, and WSe2) show indirect energy band gaps which hinders some of their applications especially in optoelectronics. In the current work, we demonstrate that most of the bilayers and even few-layers consisting of group VIB TMDs can have direct gaps by efficient weakening of their interlayer interactions via real and/or energy spaces tuning, which is based on insights from quantitative analyses of interlayer electronic hybridizations. Real space tuning here means introducing large-angle rotational misalignment between layers, which has been realized in a very recent experiment; and, energy space tuning means introducing energy mismatch between layers which can be introduced efficiently by different means thanks to the small vertical dielectric constant of 2D semiconducting TMDs. The efficient tuning in both real and energy spaces proposed here paves an avenue for indirect-direct gap regulation of homo- and hetero-junctions of TMDs and other 2D semiconductors. Notably, both tuning can be permanently preserved and hence our work is of great significance for the diverse applications of 2D semiconductors. Most van der Waals homo- and hetero-junctions of 2D transition-metal dichalcogenides of group VIB have indirect bandgaps. Here, the authors demonstrate a way of inducing direct gaps in these systems by tuning interlayer interactions via rotational misalignment or energy mismatch between layers.
{"title":"Toward direct band gaps in typical 2D transition-metal dichalcogenides junctions via real and energy spaces tuning","authors":"Mei-Yan Tian, Yu-Meng Gao, Yue-Jiao Zhang, Meng-Xue Ren, Xiao-Huan Lv, Ke-Xin Hou, Chen-Dong Jin, Hu Zhang, Ru-Qian Lian, Peng-Lai Gong, Rui-Ning Wang, Jiang-Long Wang, Xing-Qiang Shi","doi":"10.1038/s43246-024-00631-z","DOIUrl":"10.1038/s43246-024-00631-z","url":null,"abstract":"Most of the van der Waals homo- and hetero-junctions of group VIB two-dimensional (2D) transition-metal dichalcogenides (TMDs; MoS2, WS2, MoSe2, and WSe2) show indirect energy band gaps which hinders some of their applications especially in optoelectronics. In the current work, we demonstrate that most of the bilayers and even few-layers consisting of group VIB TMDs can have direct gaps by efficient weakening of their interlayer interactions via real and/or energy spaces tuning, which is based on insights from quantitative analyses of interlayer electronic hybridizations. Real space tuning here means introducing large-angle rotational misalignment between layers, which has been realized in a very recent experiment; and, energy space tuning means introducing energy mismatch between layers which can be introduced efficiently by different means thanks to the small vertical dielectric constant of 2D semiconducting TMDs. The efficient tuning in both real and energy spaces proposed here paves an avenue for indirect-direct gap regulation of homo- and hetero-junctions of TMDs and other 2D semiconductors. Notably, both tuning can be permanently preserved and hence our work is of great significance for the diverse applications of 2D semiconductors. Most van der Waals homo- and hetero-junctions of 2D transition-metal dichalcogenides of group VIB have indirect bandgaps. Here, the authors demonstrate a way of inducing direct gaps in these systems by tuning interlayer interactions via rotational misalignment or energy mismatch between layers.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00631-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142234042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1038/s43246-024-00624-y
Ani Vardanyan, Guojun Zhou, Nayoung Kim, Tetyana M. Budnyak, Vadim G. Kessler, Insung S. Choi, Zhehao Huang, Gulaim A. Seisenbaeva
Metal-organic frameworks (MOFs) have emerged as highly promising materials for hosting functional biomolecules. Here, a 1,2,4-benzenetricarboxylate ligand with a flat asymmetric shape is applied to infuse an unusual behavior to a 3D europium MOF (SLU-1). Solvent addition results in the 3D MOF splitting into a 2D one (SLU-2), and in the presence of excess water, gets cross-linked into a different 3D MOF (SLU-3) prone to spontaneous exfoliation. SLU-3 features a combination of highly hydrophilic and hydrophobic spots and serves as an attractive host for incorporating large active species. As a representative demonstration, horseradish peroxidase (HRP) is incorporated into the exfoliated 3D-layered structure by simple mixing, and secured by an outer silica layer in the form of core-shell structures. The resulting HRP-based biocatalyst exhibited enhanced stability and reusability, effectively degrading phenol. This work showcases the potential of reconfigurable MOFs, offering upheld applications through the controlled uptake and retention of biocatalytic agents. Metal-organic frameworks are promising materials for hosting functional biomolecules. Here, a 3D europium metal-organic framework could split into a 2D one upon solvent addition and re-cross-link to 3D with excess solvent which can host enzymes as a biocatalyst.
{"title":"Transformation of europium metal-organic framework from 3D via 2D into exfoliating 3D for enzyme immobilization","authors":"Ani Vardanyan, Guojun Zhou, Nayoung Kim, Tetyana M. Budnyak, Vadim G. Kessler, Insung S. Choi, Zhehao Huang, Gulaim A. Seisenbaeva","doi":"10.1038/s43246-024-00624-y","DOIUrl":"10.1038/s43246-024-00624-y","url":null,"abstract":"Metal-organic frameworks (MOFs) have emerged as highly promising materials for hosting functional biomolecules. Here, a 1,2,4-benzenetricarboxylate ligand with a flat asymmetric shape is applied to infuse an unusual behavior to a 3D europium MOF (SLU-1). Solvent addition results in the 3D MOF splitting into a 2D one (SLU-2), and in the presence of excess water, gets cross-linked into a different 3D MOF (SLU-3) prone to spontaneous exfoliation. SLU-3 features a combination of highly hydrophilic and hydrophobic spots and serves as an attractive host for incorporating large active species. As a representative demonstration, horseradish peroxidase (HRP) is incorporated into the exfoliated 3D-layered structure by simple mixing, and secured by an outer silica layer in the form of core-shell structures. The resulting HRP-based biocatalyst exhibited enhanced stability and reusability, effectively degrading phenol. This work showcases the potential of reconfigurable MOFs, offering upheld applications through the controlled uptake and retention of biocatalytic agents. Metal-organic frameworks are promising materials for hosting functional biomolecules. Here, a 3D europium metal-organic framework could split into a 2D one upon solvent addition and re-cross-link to 3D with excess solvent which can host enzymes as a biocatalyst.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00624-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1038/s43246-024-00576-3
Farshad Jafarzadeh, Luigi Angelo Castriotta, Emanuele Calabrò, Pierpaolo Spinelli, Amanda Generosi, Barbara Paci, David Becerril Rodriguez, Marco Luce, Antonio Cricenti, Francesco Di Giacomo, Fabio Matteocci, Francesca Brunetti, Aldo Di Carlo
Perovskite solar cells have rapidly advanced, achieving over 26% power conversion efficiency on the laboratory scale. However, transitioning to large-scale production remains a challenge due to limitations in conventional fabrication methods like spin coating. Here, we introduce an optimized blade coating process for the scalable fabrication of large-area (15 cm × 15 cm) perovskite solar modules with a nickel oxide hole transport layer, performed in ambient air and utilizing a non-toxic solvent system. Self-assembled monolayers between the nickel oxide and perovskite layer improve the uniformity and morphology of the perovskite film. Perovskite solar modules with a 110 cm2 active area achieve a power conversion efficiency of 12.6%. Moreover, encapsulated modules retained 84% of their initial efficiency after 1,000 hours at 85 °C in air (ISOS-T-1). This study demonstrates progress in the large-scale production of perovskite solar cells that combine efficiency with long-term stability. Perovskite solar cells and have shown great promise on the lab scale, but work is needed to scale-up their fabrication. Here, blade coating is used to fabricate 15 cm×15 cm perovskite modules with a nickel oxide hole transport layer, achieving high power conversion efficiency and stability.
{"title":"Stable and sustainable perovskite solar modules by optimizing blade coating nickel oxide deposition over 15 × 15 cm2 area","authors":"Farshad Jafarzadeh, Luigi Angelo Castriotta, Emanuele Calabrò, Pierpaolo Spinelli, Amanda Generosi, Barbara Paci, David Becerril Rodriguez, Marco Luce, Antonio Cricenti, Francesco Di Giacomo, Fabio Matteocci, Francesca Brunetti, Aldo Di Carlo","doi":"10.1038/s43246-024-00576-3","DOIUrl":"10.1038/s43246-024-00576-3","url":null,"abstract":"Perovskite solar cells have rapidly advanced, achieving over 26% power conversion efficiency on the laboratory scale. However, transitioning to large-scale production remains a challenge due to limitations in conventional fabrication methods like spin coating. Here, we introduce an optimized blade coating process for the scalable fabrication of large-area (15 cm × 15 cm) perovskite solar modules with a nickel oxide hole transport layer, performed in ambient air and utilizing a non-toxic solvent system. Self-assembled monolayers between the nickel oxide and perovskite layer improve the uniformity and morphology of the perovskite film. Perovskite solar modules with a 110 cm2 active area achieve a power conversion efficiency of 12.6%. Moreover, encapsulated modules retained 84% of their initial efficiency after 1,000 hours at 85 °C in air (ISOS-T-1). This study demonstrates progress in the large-scale production of perovskite solar cells that combine efficiency with long-term stability. Perovskite solar cells and have shown great promise on the lab scale, but work is needed to scale-up their fabrication. Here, blade coating is used to fabricate 15 cm×15 cm perovskite modules with a nickel oxide hole transport layer, achieving high power conversion efficiency and stability.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00576-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1038/s43246-024-00611-3
Max L. Neveau, William R. Meier, Hyojin Park, Michael J. Thompson, Nitish Bibhanshu, Catrin Böcher, Tomer Fishman, David Weiss, Matthew F. Chisholm, Orlando Rios, Gerd Duscher
Alloying in metal castings is one of the principal methods of strengthening an alloy for various structural and functional applications, but very rarely does it modify an alloy’s elastic modulus. We report a methodology of combining isostructural Laves phases to form a multi-component, high symmetry, isotropic phase that was discovered to enhance the elastic modulus of a cast aluminum alloy to 91.5 ± 7.4 GPa. Flux grown single crystals of the rhombicuboctahedron phase (RCO), so named for the observed morphology, were used to enhance understanding of the structure and mechanical properties of the phase. The pure RCO phase’s structure and site occupancies were co-refined using x-ray and neutron diffraction. Dynamic nanomechanical testing of the cast alloy shows the primary RCO phase has a high, relatively isotropic, elastic modulus. This RCO containing aluminum alloy is found to have a specific modulus that exceeds that of the leading Al, Mg, Steel, and Ti alloys. The elastic properties of alloys are typically insensitive to changes in microstructure. Here, an as-cast Al-Ce alloy achieves a large Young’s modulus of approximately 92 GPa, due to the presence of isotropic, high symmetry secondary phase.
{"title":"Secondary phase increases the elastic modulus of a cast aluminum-cerium alloy","authors":"Max L. Neveau, William R. Meier, Hyojin Park, Michael J. Thompson, Nitish Bibhanshu, Catrin Böcher, Tomer Fishman, David Weiss, Matthew F. Chisholm, Orlando Rios, Gerd Duscher","doi":"10.1038/s43246-024-00611-3","DOIUrl":"10.1038/s43246-024-00611-3","url":null,"abstract":"Alloying in metal castings is one of the principal methods of strengthening an alloy for various structural and functional applications, but very rarely does it modify an alloy’s elastic modulus. We report a methodology of combining isostructural Laves phases to form a multi-component, high symmetry, isotropic phase that was discovered to enhance the elastic modulus of a cast aluminum alloy to 91.5 ± 7.4 GPa. Flux grown single crystals of the rhombicuboctahedron phase (RCO), so named for the observed morphology, were used to enhance understanding of the structure and mechanical properties of the phase. The pure RCO phase’s structure and site occupancies were co-refined using x-ray and neutron diffraction. Dynamic nanomechanical testing of the cast alloy shows the primary RCO phase has a high, relatively isotropic, elastic modulus. This RCO containing aluminum alloy is found to have a specific modulus that exceeds that of the leading Al, Mg, Steel, and Ti alloys. The elastic properties of alloys are typically insensitive to changes in microstructure. Here, an as-cast Al-Ce alloy achieves a large Young’s modulus of approximately 92 GPa, due to the presence of isotropic, high symmetry secondary phase.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00611-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Formation of a single crystalline oxide semiconductor on an insulating film as a channel material capable of three-dimensional (3D) stacking would enable 3D very-large-scale integration circuits. This study presents a technique for forming single-crystalline In2O3 having no grain boundaries in a channel formation region on an insulating film using the (001) plane of c-axis-aligned crystalline indium gallium zinc oxide as a seed. Vertical field-effect transistors using the single-crystalline In2O3 had an off-state current of 10−21 A μm−1 and electrical characteristics were improved compared with those using non-single-crystalline In2O3: the subthreshold slope was improved from 95.7 to 86.7 mV dec.−1, the threshold voltage showing normally-off characteristics (0.10 V) was obtained, the threshold voltage standard deviation was improved from 0.11 to 0.05 V, the on-state current was improved from 22.5 to 28.8 μA, and a 17-digit on/off ratio was obtained at 27 °C. Three-dimensional stacking of single-crystalline oxide semiconductors on insulating films is key to large-scale integration of electronic circuits. Here, a technique is reported for single-crystalline In2O3 formation over an insulting film with no grain boundaries, achieving high processing speed and low power consumption.
在绝缘薄膜上形成单晶氧化物半导体作为能够进行三维（3D）堆叠的沟道材料，可实现三维超大规模集成电路。本研究提出了一种在绝缘薄膜上的沟道形成区域形成没有晶界的单晶 In2O3 的技术，该技术以 c 轴对齐的晶体氧化铟镓锌的 (001) 平面为种子。与使用非单晶 In2O3 的晶体管相比，使用单晶 In2O3 的垂直场效应晶体管的离态电流为 10-21 A μm-1，电气特性也有所改善：阈下斜率从 95.7 mV dec.-阈值电压显示正常关断特性（0.10 V），阈值电压标准偏差从 0.11 V 减小到 0.05 V，导通电流从 22.5 μA 减小到 28.8 μA，并且在 27 °C 时获得了 17 位数的导通/关断比。
{"title":"High-performance single-crystalline In2O3 field effect transistor toward three-dimensional large-scale integration circuits","authors":"Shunpei Yamazaki, Fumito Isaka, Toshikazu Ohno, Yuji Egi, Sachiaki Tezuka, Motomu Kurata, Hiromi Sawai, Ryosuke Motoyoshi, Etsuko Asano, Satoru Saito, Tatsuya Onuki, Takanori Matsuzaki, Michio Tajima","doi":"10.1038/s43246-024-00625-x","DOIUrl":"10.1038/s43246-024-00625-x","url":null,"abstract":"Formation of a single crystalline oxide semiconductor on an insulating film as a channel material capable of three-dimensional (3D) stacking would enable 3D very-large-scale integration circuits. This study presents a technique for forming single-crystalline In2O3 having no grain boundaries in a channel formation region on an insulating film using the (001) plane of c-axis-aligned crystalline indium gallium zinc oxide as a seed. Vertical field-effect transistors using the single-crystalline In2O3 had an off-state current of 10−21 A μm−1 and electrical characteristics were improved compared with those using non-single-crystalline In2O3: the subthreshold slope was improved from 95.7 to 86.7 mV dec.−1, the threshold voltage showing normally-off characteristics (0.10 V) was obtained, the threshold voltage standard deviation was improved from 0.11 to 0.05 V, the on-state current was improved from 22.5 to 28.8 μA, and a 17-digit on/off ratio was obtained at 27 °C. Three-dimensional stacking of single-crystalline oxide semiconductors on insulating films is key to large-scale integration of electronic circuits. Here, a technique is reported for single-crystalline In2O3 formation over an insulting film with no grain boundaries, achieving high processing speed and low power consumption.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00625-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10DOI: 10.1038/s43246-024-00616-y
Jacob P. Tavenner, Ankit Gupta, Gregory B. Thompson, Edward M. Kober, Garritt J. Tucker
Although continuum-scale segregation is a well-documented behavior in multi-species materials, detailed site-specific behavior remains largely unexplored. This is partially due to the complexity of analyzing materials at the requisite time and length scales for describing segregation with full atomic accuracy. Here, we better evaluate the segregation behavior of disordered grain boundary (GB) atomic environments through leveraging a set of Strain Functional Descriptors (SFDs) to generate an atomic descriptor (i.e., fingerprint). Using this atomic fingerprint, we resolve key relationships between atomic structure and segregation energy. Machine learning (ML) techniques are utilized in concert with this SFD fingerprint to elucidate complex relationships relating segregation potential to changes in specific features of the local Gaussian density captured by the SFDs. Finally, we identify relationships that indicate both individual and joint structure-property correlations. Linking atomic segregation energy to key structural features demonstrates the value of higher-order descriptors for uncovering complex structure-property relationships at an atomic scale. Describing site-specific segregation in multi-species materials is a computationally complex task that typically requires model simplification, at the expense of atomic accuracy, or limitation to small samples. Here, the relationships between local atomic environments at grain boundaries and their segregation energies are investigated by developing suitable machine learning atomic descriptors.
{"title":"Learning grain boundary segregation behavior through fingerprinting complex atomic environments","authors":"Jacob P. Tavenner, Ankit Gupta, Gregory B. Thompson, Edward M. Kober, Garritt J. Tucker","doi":"10.1038/s43246-024-00616-y","DOIUrl":"10.1038/s43246-024-00616-y","url":null,"abstract":"Although continuum-scale segregation is a well-documented behavior in multi-species materials, detailed site-specific behavior remains largely unexplored. This is partially due to the complexity of analyzing materials at the requisite time and length scales for describing segregation with full atomic accuracy. Here, we better evaluate the segregation behavior of disordered grain boundary (GB) atomic environments through leveraging a set of Strain Functional Descriptors (SFDs) to generate an atomic descriptor (i.e., fingerprint). Using this atomic fingerprint, we resolve key relationships between atomic structure and segregation energy. Machine learning (ML) techniques are utilized in concert with this SFD fingerprint to elucidate complex relationships relating segregation potential to changes in specific features of the local Gaussian density captured by the SFDs. Finally, we identify relationships that indicate both individual and joint structure-property correlations. Linking atomic segregation energy to key structural features demonstrates the value of higher-order descriptors for uncovering complex structure-property relationships at an atomic scale. Describing site-specific segregation in multi-species materials is a computationally complex task that typically requires model simplification, at the expense of atomic accuracy, or limitation to small samples. Here, the relationships between local atomic environments at grain boundaries and their segregation energies are investigated by developing suitable machine learning atomic descriptors.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00616-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stimuli-responsive materials constructed via the self-assembly of small biomolecules are attracting increasing attention because of their biocompatibility, sustainability, and variety of (bio)applications. Nevertheless, the research on oligosaccharide-based molecular designs for such stimuli-responsive materials (or stimuli-responsive glyco-materials) is limited, partly due to the intrinsic structural diversity of oligosaccharides and the difficulty associated with their selective chemical syntheses. Herein, we report the construction of photodegradable glyco-microfibers by the self-assembly of cellobiose derivatives bearing nitrobenzyl groups. The atomic-scale, self-assembled architecture of the photodegradable glyco-microfibers is unveiled and compared with those of pristine cellobiose and cellulose polymorphs in previous reports. Stimuli-responsive oligosaccharide-based molecular designs are limited due to their intrinsic structural diversity and difficulties in selective synthesis. Here, photodegradable glyco-microfibers are synthesized by the selfassembly of cellobiose derivatives bearing nitrobenzyl groups.
{"title":"Photodegradable glyco-microfibers fabricated by the self-assembly of cellobiose derivatives bearing nitrobenzyl groups","authors":"Bioru Okumura, Eriko Yamaguchi, Naoko Komura, Taku Ohtomi, Shin-ichiro Kawano, Hiroyasu Sato, Hiroshi Katagiri, Hiromune Ando, Masato Ikeda","doi":"10.1038/s43246-024-00622-0","DOIUrl":"10.1038/s43246-024-00622-0","url":null,"abstract":"Stimuli-responsive materials constructed via the self-assembly of small biomolecules are attracting increasing attention because of their biocompatibility, sustainability, and variety of (bio)applications. Nevertheless, the research on oligosaccharide-based molecular designs for such stimuli-responsive materials (or stimuli-responsive glyco-materials) is limited, partly due to the intrinsic structural diversity of oligosaccharides and the difficulty associated with their selective chemical syntheses. Herein, we report the construction of photodegradable glyco-microfibers by the self-assembly of cellobiose derivatives bearing nitrobenzyl groups. The atomic-scale, self-assembled architecture of the photodegradable glyco-microfibers is unveiled and compared with those of pristine cellobiose and cellulose polymorphs in previous reports. Stimuli-responsive oligosaccharide-based molecular designs are limited due to their intrinsic structural diversity and difficulties in selective synthesis. Here, photodegradable glyco-microfibers are synthesized by the selfassembly of cellobiose derivatives bearing nitrobenzyl groups.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00622-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
At present, adhesives widely used in various industries are mainly synthesized from organic chemical raw materials, and research on replacing traditional chemical raw materials with renewable biomass resources to synthesize adhesives is urgently needed. Adhesives possessing colloidal properties are highly favored due to their distinctive self-assembly capability, and robust reinforcement effects. Here, using cellulose as the sole raw material and following a simple and inexpensive strategy, we prepare a high-performance all-cellulose colloidal adhesive that is resistant to boiling water. We achieve a dry-shear strength of 1.97 MPa with this adhesive and a bonding strength of 0.81 MPa after a cycle of boiling-drying-boiling. The curing mechanism of the adhesive are verified using molecular dynamics simulations. These all-cellulose colloidal adhesives demonstrate great potential to replace traditional adhesives in the near future. Adhesives are commonly made from chemically synthesized raw materials. Here, a colloidal adhesive made entirely from cellulose shows strong mechanical properties and resistance to boiling water.
{"title":"All-cellulose colloidal adhesive","authors":"Xin Zhao, Zeyu Zhang, Tian Ju, Yuyan Jiang, Ming Wei, Jian Li, Yanjun Xie, Shaoliang Xiao","doi":"10.1038/s43246-024-00630-0","DOIUrl":"10.1038/s43246-024-00630-0","url":null,"abstract":"At present, adhesives widely used in various industries are mainly synthesized from organic chemical raw materials, and research on replacing traditional chemical raw materials with renewable biomass resources to synthesize adhesives is urgently needed. Adhesives possessing colloidal properties are highly favored due to their distinctive self-assembly capability, and robust reinforcement effects. Here, using cellulose as the sole raw material and following a simple and inexpensive strategy, we prepare a high-performance all-cellulose colloidal adhesive that is resistant to boiling water. We achieve a dry-shear strength of 1.97 MPa with this adhesive and a bonding strength of 0.81 MPa after a cycle of boiling-drying-boiling. The curing mechanism of the adhesive are verified using molecular dynamics simulations. These all-cellulose colloidal adhesives demonstrate great potential to replace traditional adhesives in the near future. Adhesives are commonly made from chemically synthesized raw materials. Here, a colloidal adhesive made entirely from cellulose shows strong mechanical properties and resistance to boiling water.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00630-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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