Pub Date : 2025-01-01Epub Date: 2025-08-22DOI: 10.1038/s41427-025-00614-7
Junsang Lee, Jinheon Jeong, Van Phuc Nguyen, Seokkyoon Hong, Yannis M Paulus, Chi Hwan Lee
Microneedles (MNs) have emerged as a promising technology for minimally invasive drug delivery, offering significant advantages in the treatment of ocular diseases. These miniaturized needles enable precise, localized drug delivery directly into specific tissues of the eye, such as the cornea, sclera, vitreous, or retina, while minimizing pain and discomfort. MNs can be fabricated from various biocompatible materials, including metals, silicon, and biodegradable polymers, making them highly adaptable to various clinical applications. Recent advancements in MN design include the integration of 3D printing technologies to create highly customized geometries for improved drug delivery precision, the use of smart materials that enable stimuli-responsive and sustained drug release, and the development of hybrid microneedles combining different polymers to enhance both mechanical strength and controlled drug release. These innovations have established MNs as a superior alternative to traditional methods like eye drops or intravitreal injections, which often face issues of limited bioavailability and patient compliance. This review summarizes the current state of research on MN-based ocular drug delivery, focusing on material developments, fabrication methods, drug release mechanisms, and implantation techniques. Future directions for MN technology in ophthalmology are also discussed, highlighting its potential to improve treatment outcomes for complex ocular diseases.
{"title":"Microneedles for controlled and sustained intraocular drug delivery.","authors":"Junsang Lee, Jinheon Jeong, Van Phuc Nguyen, Seokkyoon Hong, Yannis M Paulus, Chi Hwan Lee","doi":"10.1038/s41427-025-00614-7","DOIUrl":"10.1038/s41427-025-00614-7","url":null,"abstract":"<p><p>Microneedles (MNs) have emerged as a promising technology for minimally invasive drug delivery, offering significant advantages in the treatment of ocular diseases. These miniaturized needles enable precise, localized drug delivery directly into specific tissues of the eye, such as the cornea, sclera, vitreous, or retina, while minimizing pain and discomfort. MNs can be fabricated from various biocompatible materials, including metals, silicon, and biodegradable polymers, making them highly adaptable to various clinical applications. Recent advancements in MN design include the integration of 3D printing technologies to create highly customized geometries for improved drug delivery precision, the use of smart materials that enable stimuli-responsive and sustained drug release, and the development of hybrid microneedles combining different polymers to enhance both mechanical strength and controlled drug release. These innovations have established MNs as a superior alternative to traditional methods like eye drops or intravitreal injections, which often face issues of limited bioavailability and patient compliance. This review summarizes the current state of research on MN-based ocular drug delivery, focusing on material developments, fabrication methods, drug release mechanisms, and implantation techniques. Future directions for MN technology in ophthalmology are also discussed, highlighting its potential to improve treatment outcomes for complex ocular diseases.</p>","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"17 1","pages":"33"},"PeriodicalIF":8.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12370535/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144963178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01Epub Date: 2025-03-07DOI: 10.1038/s41427-025-00590-y
Gyanendra Panchal, Federico Stramaglia, Pawan Kumar, Enrico Schierle, Klaus Habicht, Carlos A F Vaz, Katharina Fritsch
Controlling the correlations and electronic reconstruction at the interface of transition metal oxide heterostructures provides a new pathway for tuning their unique physical properties. Here, we investigate the effects of interfacial nonstoichiometry and vertical phase separation on the magnetic properties and proximity-induced magnetism of epitaxial La0.7Sr0.3MnO3 (LSMO)/SrTiO3(001) oxide heterostructures. We also reinvestigate the recently observed inverse hysteresis behavior reported for this system, which we find emanates from the remanent field of the superconducting solenoid and not from antiferromagnetic intra-layer exchange coupling in low coercivity LSMO thin films. Combined atomically resolved electron energy loss spectroscopy, element-specific X-ray magnetic circular dichroism, and interface-sensitive polarized soft X-ray resonant magnetic reflectivity show the formation of a Mn3+-enriched interfacial LSMO layer, of a Ti3+-derived magnetic interface layer coupled ferromagnetically to La0.7Sr0.3MnO3, together with a small density of O-vacancies at the interface. These results not only advance the understanding of the magnetism and spin structure of correlated oxide interfaces but also hold promise for practical applications, especially in devices where the performance relies on the control and influence of spin polarization currents by the interfacial spin structure.
{"title":"Atomic scale determination of magnetism and stoichiometry at the La<sub>0.7</sub>Sr<sub>0.3</sub>MnO<sub>3</sub>/SrTiO<sub>3</sub> interface: investigation of inverse hysteresis.","authors":"Gyanendra Panchal, Federico Stramaglia, Pawan Kumar, Enrico Schierle, Klaus Habicht, Carlos A F Vaz, Katharina Fritsch","doi":"10.1038/s41427-025-00590-y","DOIUrl":"10.1038/s41427-025-00590-y","url":null,"abstract":"<p><p>Controlling the correlations and electronic reconstruction at the interface of transition metal oxide heterostructures provides a new pathway for tuning their unique physical properties. Here, we investigate the effects of interfacial nonstoichiometry and vertical phase separation on the magnetic properties and proximity-induced magnetism of epitaxial La<sub>0.7</sub>Sr<sub>0.3</sub>MnO<sub>3</sub> (LSMO)/SrTiO<sub>3</sub>(001) oxide heterostructures. We also reinvestigate the recently observed inverse hysteresis behavior reported for this system, which we find emanates from the remanent field of the superconducting solenoid and not from antiferromagnetic intra-layer exchange coupling in low coercivity LSMO thin films. Combined atomically resolved electron energy loss spectroscopy, element-specific X-ray magnetic circular dichroism, and interface-sensitive polarized soft X-ray resonant magnetic reflectivity show the formation of a Mn<sup>3+</sup>-enriched interfacial LSMO layer, of a Ti<sup>3+</sup>-derived magnetic interface layer coupled ferromagnetically to La<sub>0.7</sub>Sr<sub>0.3</sub>MnO<sub>3</sub>, together with a small density of O-vacancies at the interface. These results not only advance the understanding of the magnetism and spin structure of correlated oxide interfaces but also hold promise for practical applications, especially in devices where the performance relies on the control and influence of spin polarization currents by the interfacial spin structure.</p>","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"17 1","pages":"9"},"PeriodicalIF":8.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11885156/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wadsley–Roth phase TiNb2O7, with an octahedral network consisting of TiO6 and NbO6, has attracted significant attention as a negative electrode material for lithium-ion batteries in recent years owing to its excellent safety and high discharge capacity. In this work, we investigated the effect of the network structure (intermediate-range structure), which is considered to form Li+ conduction pathways, on the electrode properties of TiNb2O7. To this end, we prepared TiNb2O7 samples with different charge/discharge properties and generated atomic configurations that simultaneously reproduce both total scattering and Bragg profile data. Topological analyses based on persistent homology demonstrated that the network disorder hidden in the average structure (crystal structure) significantly degrades the negative electrode properties. In conclusion, controlling the network topology is considered the key to improving the negative electrode properties of TiNb2O7. In recent years, the need for safer and more efficient rechargeable batteries has grown due to the increasing use of renewable energy. Traditional lithium-ion batteries have safety risks, such as catching fire, especially when charged quickly. Researchers are exploring new materials to improve battery safety and performance. They studied a material called TiNb2O7, which could be a safer alternative for battery electrodes. Researchers prepared TiNb2O7 using different methods and tested its performance in batteries. They used advanced techniques to analyze the material’s structure at the atomic level. This study focused on how the arrangement of atoms affects the battery’s ability to store and release energy. The results showed TiNb2O7 has potential as a battery electrode, offering good capacity and safety. The study concluded that understanding the atomic structure can guide the development of better battery materials. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author. In this work, we focused on Wadsley–Roth phase TiNb2O7 with an octahedral network as a negative electrode material for lithium-ion batteries and investigated the effect of the network structure, which is considered to form Li+ conduction pathways, on the electrode properties. To this end, we prepared samples with different charge/discharge properties and generated atomic configurations that simultaneously reproduce both total scattering and Bragg profile data. Topological analyses based on persistent homology demonstrated that the network disorder significantly degrades the electrode properties.
{"title":"Relationship between network topology and negative electrode properties in Wadsley–Roth phase TiNb2O7","authors":"Naoto Kitamura, Hikari Matsubara, Koji Kimura, Ippei Obayashi, Yohei Onodera, Ken Nakashima, Hidetoshi Morita, Motoki Shiga, Yasuhiro Harada, Chiaki Ishibashi, Yasushi Idemoto, Koichi Hayashi","doi":"10.1038/s41427-024-00581-5","DOIUrl":"10.1038/s41427-024-00581-5","url":null,"abstract":"Wadsley–Roth phase TiNb2O7, with an octahedral network consisting of TiO6 and NbO6, has attracted significant attention as a negative electrode material for lithium-ion batteries in recent years owing to its excellent safety and high discharge capacity. In this work, we investigated the effect of the network structure (intermediate-range structure), which is considered to form Li+ conduction pathways, on the electrode properties of TiNb2O7. To this end, we prepared TiNb2O7 samples with different charge/discharge properties and generated atomic configurations that simultaneously reproduce both total scattering and Bragg profile data. Topological analyses based on persistent homology demonstrated that the network disorder hidden in the average structure (crystal structure) significantly degrades the negative electrode properties. In conclusion, controlling the network topology is considered the key to improving the negative electrode properties of TiNb2O7. In recent years, the need for safer and more efficient rechargeable batteries has grown due to the increasing use of renewable energy. Traditional lithium-ion batteries have safety risks, such as catching fire, especially when charged quickly. Researchers are exploring new materials to improve battery safety and performance. They studied a material called TiNb2O7, which could be a safer alternative for battery electrodes. Researchers prepared TiNb2O7 using different methods and tested its performance in batteries. They used advanced techniques to analyze the material’s structure at the atomic level. This study focused on how the arrangement of atoms affects the battery’s ability to store and release energy. The results showed TiNb2O7 has potential as a battery electrode, offering good capacity and safety. The study concluded that understanding the atomic structure can guide the development of better battery materials. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author. In this work, we focused on Wadsley–Roth phase TiNb2O7 with an octahedral network as a negative electrode material for lithium-ion batteries and investigated the effect of the network structure, which is considered to form Li+ conduction pathways, on the electrode properties. To this end, we prepared samples with different charge/discharge properties and generated atomic configurations that simultaneously reproduce both total scattering and Bragg profile data. Topological analyses based on persistent homology demonstrated that the network disorder significantly degrades the electrode properties.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"16 1","pages":"1-13"},"PeriodicalIF":8.6,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-024-00581-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143187394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Polarization-sensitive photodetection enhances scene information capture, crucial for modern optoelectronic devices. One-dimensional (1D) materials with intrinsic anisotropy, capable of directly sensing polarized light, are promising for such photodetectors. NbTe4, a quasi-1D transition metal tetra-chalcogenide, offers significant benefits for polarization-sensitive photodetection due to its structural anisotropy. Nonetheless, to date, the anisotropic properties of 1D NbTe4 have not been reported. Herein, NbTe4 nanobelts were synthesized via mechanical exfoliation from needle-like bulk crystals, and their anisotropic and optoelectronic properties were comprehensively studied. Angle-resolved polarized Raman spectroscopy, in conjunction with azimuth-dependent reflectance difference microscopy, confirmed that 1D NbTe₄ exhibits intrinsic structural and in-plane optical anisotropy. The 1D NbTe4 device demonstrated characteristic anisotropic photodetection behavior, achieving dichroic ratios of 1.16 at 671 nm and 1.25 at 1064 nm. Meanwhile, the device exhibits a pronounced photothermoelectric effect, conferring a broad spectral photoresponse ranging from visible to near-infrared wavelengths (532-1064 nm), with a rapid response time of 158 ms. This study demonstrates that NbTe4 inherently possesses in-plane anisotropy, making it a promising candidate for polarization-sensitive photodetection applications. The 1D transition metal tetra-chalcogenides, NbTe4, with inherent structural and optical anisotropy, has been used to develop a polarization-sensitive photodetector. The NbTe4 flakes-based device displays pronounced anisotropic photodetection properties with a dichroic ratio of 1.16 at 671 nm and 1.25 at 1064 nm. It also demonstrates a significant photothermoelectric effect, enabling a broad spectral response from the visible to near-infrared spectrum (532-1064 nm).
{"title":"Intrinsically anisotropic 1D NbTe4 for self-powered polarization-sensitive photodetection","authors":"Huahu Luo, Fafa Wu, Chaowei He, Wanfu Shen, Chunguang Hu, Weina Zhao, Peng Yu, Guowei Yang","doi":"10.1038/s41427-024-00580-6","DOIUrl":"10.1038/s41427-024-00580-6","url":null,"abstract":"Polarization-sensitive photodetection enhances scene information capture, crucial for modern optoelectronic devices. One-dimensional (1D) materials with intrinsic anisotropy, capable of directly sensing polarized light, are promising for such photodetectors. NbTe4, a quasi-1D transition metal tetra-chalcogenide, offers significant benefits for polarization-sensitive photodetection due to its structural anisotropy. Nonetheless, to date, the anisotropic properties of 1D NbTe4 have not been reported. Herein, NbTe4 nanobelts were synthesized via mechanical exfoliation from needle-like bulk crystals, and their anisotropic and optoelectronic properties were comprehensively studied. Angle-resolved polarized Raman spectroscopy, in conjunction with azimuth-dependent reflectance difference microscopy, confirmed that 1D NbTe₄ exhibits intrinsic structural and in-plane optical anisotropy. The 1D NbTe4 device demonstrated characteristic anisotropic photodetection behavior, achieving dichroic ratios of 1.16 at 671 nm and 1.25 at 1064 nm. Meanwhile, the device exhibits a pronounced photothermoelectric effect, conferring a broad spectral photoresponse ranging from visible to near-infrared wavelengths (532-1064 nm), with a rapid response time of 158 ms. This study demonstrates that NbTe4 inherently possesses in-plane anisotropy, making it a promising candidate for polarization-sensitive photodetection applications. The 1D transition metal tetra-chalcogenides, NbTe4, with inherent structural and optical anisotropy, has been used to develop a polarization-sensitive photodetector. The NbTe4 flakes-based device displays pronounced anisotropic photodetection properties with a dichroic ratio of 1.16 at 671 nm and 1.25 at 1064 nm. It also demonstrates a significant photothermoelectric effect, enabling a broad spectral response from the visible to near-infrared spectrum (532-1064 nm).","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"16 1","pages":"1-10"},"PeriodicalIF":8.6,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-024-00580-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143187393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-29DOI: 10.1038/s41427-024-00579-z
Lingyong Zeng, Longfu Li, Kuan Li, Rui Chen, Huixia Luo
High-entropy materials (HEMs) exhibit significant potential for diverse applications owing to their tunable properties, which can be precisely engineered through the selection of specific elements and the modification of stoichiometric ratios. The discovery of superconductivity in HEMs has garnered considerable interest, leading to accelerated advancements in this field in recent years. This review provides an overview of various high-entropy superconductors, highlighting their distinct features, such as disordered crystal structure, factors affecting the critical temperature (Tc), unconventional superconductivity, and topological bands. A perspective on this field is subsequently proposed, drawing upon insights from recently published academic literature. The objective is to provide researchers with a comprehensive and clear understanding of the newly developed high-entropy superconductivity, thereby catalyzing further advancements in this domain. The discovery of superconductivity in high-entropy materials has garnered considerable interest, leading to accelerated advancements in this field in recent years. Some interesting phenomena have been found in high-entropy superconductors, such as the robustness of superconductivity to pressure, large upper critical field, strong coupling behavior, and topological band structure. Accordingly, the present review article is dedicated to summarizing the recently reported works on the structural type and physical properties of high-entropy superconductors, as well as their potential applications. Finally, we provide our perspective on the future challenges of high-entropy superconductors.
{"title":"Recent advances in high-entropy superconductors","authors":"Lingyong Zeng, Longfu Li, Kuan Li, Rui Chen, Huixia Luo","doi":"10.1038/s41427-024-00579-z","DOIUrl":"10.1038/s41427-024-00579-z","url":null,"abstract":"High-entropy materials (HEMs) exhibit significant potential for diverse applications owing to their tunable properties, which can be precisely engineered through the selection of specific elements and the modification of stoichiometric ratios. The discovery of superconductivity in HEMs has garnered considerable interest, leading to accelerated advancements in this field in recent years. This review provides an overview of various high-entropy superconductors, highlighting their distinct features, such as disordered crystal structure, factors affecting the critical temperature (Tc), unconventional superconductivity, and topological bands. A perspective on this field is subsequently proposed, drawing upon insights from recently published academic literature. The objective is to provide researchers with a comprehensive and clear understanding of the newly developed high-entropy superconductivity, thereby catalyzing further advancements in this domain. The discovery of superconductivity in high-entropy materials has garnered considerable interest, leading to accelerated advancements in this field in recent years. Some interesting phenomena have been found in high-entropy superconductors, such as the robustness of superconductivity to pressure, large upper critical field, strong coupling behavior, and topological band structure. Accordingly, the present review article is dedicated to summarizing the recently reported works on the structural type and physical properties of high-entropy superconductors, as well as their potential applications. Finally, we provide our perspective on the future challenges of high-entropy superconductors.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"16 1","pages":"1-13"},"PeriodicalIF":8.6,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-024-00579-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143187392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1038/s41427-024-00578-0
Imhwan Kim, Jinseok Ryu, Eunsu Lee, Sangmin Lee, Seokje Lee, Wonwoo Suh, Jamin Lee, Miyoung Kim, Hong seok Oh, Gyu-Chul Yi
We report on the electrical characteristics of field-effect transistors (FETs) and Schottky diodes based on In2Te3 grown on hexagonal boron nitride (h-BN) substrates utilizing molecular beam epitaxy (MBE). A two-step growth method was used to increase surface coverage and large grain sizes for high-quality In2Te3. Scanning transmission electron microscopy (STEM) imaging revealed an atomically clean and abrupt interface between the In2Te3 and h-BN substrates. Compared with the previously reported In2Te3 FETs, the MBE-grown In2Te3 FETs exhibited superior electrical properties, including a mobility of 6.07 cm2 V−1 s−1, a subthreshold swing close to 6 V dec−1, and an impressive on/off ratio of approximately 105. Furthermore, the Ti/In2Te3 Schottky diodes exhibit a low saturation current of 0.4 nA, an ideality factor of 26.7, and a Schottky barrier height of 0.68 eV. We report on the fabrication and electrical characteristics of In2Te3 thin films grown on h-BN using molecular beam epitaxy(MBE). Cross-sectional scanning transmission electron microscopy images showed an atomically clean and abrupt interface between In2Te3 and h-BN substrates. The MBE-grown In2Te3 electronic devices exhibited superior electrical properties compared to previously reported In2Te3 field effect transistors(FETs) and In2Te3-based Schottky diodes.
本文报道了利用分子束外延技术（MBE）在六方氮化硼（h-BN）衬底上生长的基于In2Te3的场效应晶体管（fet）和肖特基二极管的电学特性。采用两步生长法制备了高质量的In2Te3，增加了表面覆盖度和晶粒尺寸。扫描透射电子显微镜（STEM）成像显示In2Te3和h-BN衬底之间有一个原子清洁和突然的界面。与先前报道的In2Te3 fet相比，mbe生长的In2Te3 fet具有优异的电学性能，包括迁移率为6.07 cm2 V−1 s−1，亚阈值摆幅接近6 V dec−1，以及令人印象深刻的约105的开/关比。此外，Ti/In2Te3肖特基二极管的饱和电流为0.4 nA，理想因数为26.7，肖特基势垒高度为0.68 eV。本文报道了利用分子束外延（MBE）在h-BN上生长的In2Te3薄膜的制备及其电学特性。横断面扫描透射电子显微镜图像显示，In2Te3和h-BN衬底之间有一个原子清洁和突然的界面。与先前报道的In2Te3场效应晶体管（fet）和基于In2Te3的肖特基二极管相比，mbe生长的In2Te3电子器件表现出优越的电学性能。
{"title":"Molecular beam epitaxial In2Te3 electronic devices","authors":"Imhwan Kim, Jinseok Ryu, Eunsu Lee, Sangmin Lee, Seokje Lee, Wonwoo Suh, Jamin Lee, Miyoung Kim, Hong seok Oh, Gyu-Chul Yi","doi":"10.1038/s41427-024-00578-0","DOIUrl":"10.1038/s41427-024-00578-0","url":null,"abstract":"We report on the electrical characteristics of field-effect transistors (FETs) and Schottky diodes based on In2Te3 grown on hexagonal boron nitride (h-BN) substrates utilizing molecular beam epitaxy (MBE). A two-step growth method was used to increase surface coverage and large grain sizes for high-quality In2Te3. Scanning transmission electron microscopy (STEM) imaging revealed an atomically clean and abrupt interface between the In2Te3 and h-BN substrates. Compared with the previously reported In2Te3 FETs, the MBE-grown In2Te3 FETs exhibited superior electrical properties, including a mobility of 6.07 cm2 V−1 s−1, a subthreshold swing close to 6 V dec−1, and an impressive on/off ratio of approximately 105. Furthermore, the Ti/In2Te3 Schottky diodes exhibit a low saturation current of 0.4 nA, an ideality factor of 26.7, and a Schottky barrier height of 0.68 eV. We report on the fabrication and electrical characteristics of In2Te3 thin films grown on h-BN using molecular beam epitaxy(MBE). Cross-sectional scanning transmission electron microscopy images showed an atomically clean and abrupt interface between In2Te3 and h-BN substrates. The MBE-grown In2Te3 electronic devices exhibited superior electrical properties compared to previously reported In2Te3 field effect transistors(FETs) and In2Te3-based Schottky diodes.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"16 1","pages":"1-6"},"PeriodicalIF":8.6,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-024-00578-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143187391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1038/s41427-024-00576-2
A. D’Elia, V. Polewczyk, A. Y. Petrov, G. Vinai, L. Li, C. W. Zou, S. J. Rezvani, A. Marcelli
We explore how strain impacts the band structure of metallic-phase VO2 thin films deposited on TiO2(101) substrates. Employing a combination of X-ray absorption linear dichroism and valence band measurements, we demonstrate that strain can alter the intrinsic band structure anisotropy of metallic VO2. Our findings reveal that reducing the thickness of VO2 films leads to a more isotropic band structure. This observation is further supported by an analysis of the electronic population redistribution in the $${d}_{{||}}{-}{pi }^{* }$$ bands, which affects the screening length and induces effective mass renormalization. Overall, our results underscore the potential of strain manipulation in tailoring the electronic structure uniformity of thin films, thereby expanding the scope for engineering VO2 functionalities. In this article we studied the evolution of band anisotropy in strained VO2(101) thin films. We found out that strain works as a control agent for the anisotropy and thus controls the features of VO2 bands structure. For this crystal orientation a large strain corresponds to a more homogeneous electronic structure of VO2. This impacts the electrons population redistribution between d|| and π bands, the screening length and the effective mass. By controlling the anisotropy and the band structure properties our results can ease the integration of VO2 into complex electronics.
{"title":"Band anisotropy and effective mass renormalization in strained metallic VO2 (101) thin films","authors":"A. D’Elia, V. Polewczyk, A. Y. Petrov, G. Vinai, L. Li, C. W. Zou, S. J. Rezvani, A. Marcelli","doi":"10.1038/s41427-024-00576-2","DOIUrl":"10.1038/s41427-024-00576-2","url":null,"abstract":"We explore how strain impacts the band structure of metallic-phase VO2 thin films deposited on TiO2(101) substrates. Employing a combination of X-ray absorption linear dichroism and valence band measurements, we demonstrate that strain can alter the intrinsic band structure anisotropy of metallic VO2. Our findings reveal that reducing the thickness of VO2 films leads to a more isotropic band structure. This observation is further supported by an analysis of the electronic population redistribution in the $${d}_{{||}}{-}{pi }^{* }$$ bands, which affects the screening length and induces effective mass renormalization. Overall, our results underscore the potential of strain manipulation in tailoring the electronic structure uniformity of thin films, thereby expanding the scope for engineering VO2 functionalities. In this article we studied the evolution of band anisotropy in strained VO2(101) thin films. We found out that strain works as a control agent for the anisotropy and thus controls the features of VO2 bands structure. For this crystal orientation a large strain corresponds to a more homogeneous electronic structure of VO2. This impacts the electrons population redistribution between d|| and π bands, the screening length and the effective mass. By controlling the anisotropy and the band structure properties our results can ease the integration of VO2 into complex electronics.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"16 1","pages":"1-8"},"PeriodicalIF":8.6,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-024-00576-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143187390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-15DOI: 10.1038/s41427-024-00577-1
Katsuaki Nakazawa, Kazutaka Mitsuishi, Konstantin Iakoubovskii, Shinji Kohara, Koichi Tsuchiya
Dynamical and structural heterogeneities play an important role in glass transition phenomena. However, the relation between these heterogeneities is not fully revealed. In this study, we simultaneously observed these heterogeneities near the glass transition temperature in Zr50Cu40Al10 using five-dimensional scanning transmission electron microscopy, which can record the spatiotemporal distribution of diffraction patterns. The heterogeneities were visualized with sub-nanometer resolution, and a correlation between them was measured up to the glass transition temperature. We verified that ordered structures had slow dynamics, and the order decreased as the temperature increased. Dynamical and structural heterogeneities play important roles in glass transition. However, the relationship between these heterogeneities has not been fully revealed. In this study, we simultaneously observed these heterogeneities near the glass transition temperature in Zr50Cu40Al10 via five-dimensional scanning transmission electron microscopy (5D-STEM), which can record the spatiotemporal distribution of diffraction patterns. We estimated local dynamics from the temporal series of diffraction patterns and local structural orders from the diffraction patterns themselves. By performing this estimation for all scanning points, we visualized the heterogeneities and found the correlation between them, which indicated that ordered structures tended to have slow dynamics.
{"title":"Structure-dynamics relation in metallic glass revealed by 5-dimensional scanning transmission electron microscopy","authors":"Katsuaki Nakazawa, Kazutaka Mitsuishi, Konstantin Iakoubovskii, Shinji Kohara, Koichi Tsuchiya","doi":"10.1038/s41427-024-00577-1","DOIUrl":"10.1038/s41427-024-00577-1","url":null,"abstract":"Dynamical and structural heterogeneities play an important role in glass transition phenomena. However, the relation between these heterogeneities is not fully revealed. In this study, we simultaneously observed these heterogeneities near the glass transition temperature in Zr50Cu40Al10 using five-dimensional scanning transmission electron microscopy, which can record the spatiotemporal distribution of diffraction patterns. The heterogeneities were visualized with sub-nanometer resolution, and a correlation between them was measured up to the glass transition temperature. We verified that ordered structures had slow dynamics, and the order decreased as the temperature increased. Dynamical and structural heterogeneities play important roles in glass transition. However, the relationship between these heterogeneities has not been fully revealed. In this study, we simultaneously observed these heterogeneities near the glass transition temperature in Zr50Cu40Al10 via five-dimensional scanning transmission electron microscopy (5D-STEM), which can record the spatiotemporal distribution of diffraction patterns. We estimated local dynamics from the temporal series of diffraction patterns and local structural orders from the diffraction patterns themselves. By performing this estimation for all scanning points, we visualized the heterogeneities and found the correlation between them, which indicated that ordered structures tended to have slow dynamics.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"16 1","pages":"1-7"},"PeriodicalIF":8.6,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-024-00577-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143187389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
IoT sensors are crucial for visualizing multidimensional and multimodal information and enabling future IT applications/services such as cyber-physical spaces, digital twins, autonomous driving, smart cities and virtual/augmented reality (VR or AR). However, IoT sensors need to be battery-free to realistically manage and maintain the growing number of available sensing devices. Here, we provide a novel sensor design approach that employs metasurfaces to enable multifunctional sensing without requiring an external power source. Importantly, unlike existing metasurface-based sensors, our metasurfaces can sense multiple physical parameters even at a fixed frequency by breaking classic harmonic oscillations in the time domain, making the proposed sensors viable for usage with limited frequency resources. Moreover, we provide a method for predicting physical parameters via the machine learning-based approach of random forest regression. The sensing performance was confirmed by estimating the temperature and light intensity, and excellent determination coefficients larger than 0.96 were achieved. Our study affords new opportunities for sensing multiple physical properties without relying on an external power source or requiring multiple frequencies, which markedly simplifies and facilitates the design of next-generation wireless communication systems. Metasurface-based sensors provide a battery-free sensing solution for maintaining numerous IoT devices with little human resources. However, the conventional method exploited resonant mechanisms associated with multiple physical parameters through different frequencies, although available frequencies were strictly limited. We report the first sensor design approach using circuit-based metasurfaces that offer a higher degree of freedom to design time-varying scattering profiles associated with multiple physical properties at a single frequency. Our prototype detects light intensity and temperature with an excellent determination coefficient above 0.96 via a machine-learning technique.
{"title":"Metasurface-enabled multifunctional single-frequency sensors without external power","authors":"Masaya Tashiro, Kosuke Ide, Kosei Asano, Satoshi Ishii, Yuta Sugiura, Akira Uchiyama, Hiroki Wakatsuchi","doi":"10.1038/s41427-024-00574-4","DOIUrl":"10.1038/s41427-024-00574-4","url":null,"abstract":"IoT sensors are crucial for visualizing multidimensional and multimodal information and enabling future IT applications/services such as cyber-physical spaces, digital twins, autonomous driving, smart cities and virtual/augmented reality (VR or AR). However, IoT sensors need to be battery-free to realistically manage and maintain the growing number of available sensing devices. Here, we provide a novel sensor design approach that employs metasurfaces to enable multifunctional sensing without requiring an external power source. Importantly, unlike existing metasurface-based sensors, our metasurfaces can sense multiple physical parameters even at a fixed frequency by breaking classic harmonic oscillations in the time domain, making the proposed sensors viable for usage with limited frequency resources. Moreover, we provide a method for predicting physical parameters via the machine learning-based approach of random forest regression. The sensing performance was confirmed by estimating the temperature and light intensity, and excellent determination coefficients larger than 0.96 were achieved. Our study affords new opportunities for sensing multiple physical properties without relying on an external power source or requiring multiple frequencies, which markedly simplifies and facilitates the design of next-generation wireless communication systems. Metasurface-based sensors provide a battery-free sensing solution for maintaining numerous IoT devices with little human resources. However, the conventional method exploited resonant mechanisms associated with multiple physical parameters through different frequencies, although available frequencies were strictly limited. We report the first sensor design approach using circuit-based metasurfaces that offer a higher degree of freedom to design time-varying scattering profiles associated with multiple physical properties at a single frequency. Our prototype detects light intensity and temperature with an excellent determination coefficient above 0.96 via a machine-learning technique.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":"16 1","pages":"1-10"},"PeriodicalIF":8.6,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41427-024-00574-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143187396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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