Nanotechnology最新文献

{"title":"Direct observations of nucleation and early-stage growth of Au-catalyzed GaAs nanowires on Si(111).","authors":"Christopher R Y Andersen, Sebastian Lehmann, Marcus Tornberg, Carina B Maliakkal, Daniel Jacobsson, Kristian S Mølhave, Kimberly A Dick","doi":"10.1088/1361-6528/adae17","DOIUrl":"10.1088/1361-6528/adae17","url":null,"abstract":"<p><p>Developing a reliable procedure for the growth of III-V nanowires (NW) on silicon (Si) substrates remains a significant challenge, as current methods rely on trial-and-error approaches with varying interpretations of critical process steps such as sample preparation, Au-Si alloy formation in the growth reactor, and NW alignment. Addressing these challenges is essential for enabling high-performance electronic and optoelectronic devices that combine the superior properties of III-V NW semiconductors with the well-established Si-based technology. Combining conventional scalable growth methods, such as metalorganic chemical vapor deposition (MOCVD) with<i>in situ</i>characterization using environmental transmission electron microscopy (ETEM-MOCVD) enables a deeper understanding of the growth dynamics, if that knowledge is transferable to the scalable processes. We report on successful epitaxial growth of Au-catalyzed GaAs NWs on Si(111) substrates using micro-electromechanical system chips with monocrystalline Si-cantilevers in both conventional MOCVD and ETEM-MOCVD systems. The conventional MOCVD provided a framework for initial parameter tuning, while ETEM-MOCVD offered valuable insights into early nucleation and catalyst-substrate interactions. Our findings show that nucleation is significantly influenced by the removal of native oxide layers and the initial formation of the Au-Si alloy. Our<i>in situ</i>studies revealed different NW-substrate interfaces, essential for optimizing the epitaxial growth process. We identified three typical configurations of NW 'roots', each impacted by growth conditions and preparation steps, affecting the structural and potentially the optical properties of the NWs. Similarly, doping from the Si-substrate may affect both optical and electrical properties; however, compositional analysis revealed no traces of Si in NWs post-nucleation and a small amount in the catalytic droplet. Our research highlights the importance of<i>in situ</i>studies for a comprehensive understanding of nucleation mechanisms, paving the way for optimizing III-V NW growth on Si substrates and developing high-performance III-V/Si devices.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143033688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combined feature of enhanced stability and multi-level switching observed in TiN/Ta₂O₅/Ag-NPs/ITO/PET structure.","authors":"Su Hu, Kang'an Jiang, Yunyang He, Peng Bao, Nan Su, Xinhui Zhao, Hui Wang","doi":"10.1088/1361-6528/ada9a3","DOIUrl":"10.1088/1361-6528/ada9a3","url":null,"abstract":"<p><p>Both stability and multi-level switching are crucial performance aspects for resistive random-access memory (RRAM), each playing a significant role in improving overall device performance. In this study, we successfully integrate these two features into a single RRAM configuration by embedding Ag-nanoparticles (Ag-NPs) into the TiN/Ta₂O₅/ITO structure. The device exhibits substantially lower switching voltages, a larger switching ratio, and multi-level switching phenomena compared to many other nanoparticle-embedded devices. We attribute it to the embedded Ag-NPs effectively switching the mechanism of conductive filaments and the controlled distribution of Ag-NPs facilitates the occurrence of multi-level switching. Additionally, the fabricated structure demonstrated an impressive optical transmittance of nearly 85%. Undoubtedly, this combined feature of RRAM not only enhances stability but also enables multi-level switching, thereby demonstrating an approach to fabricating versatile and practical electronic devices aimed at boosting storage capacity and speed.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143008785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Infrared photoresponse of GeSiSn p-i-n photodiodes based on quantum dots, quantum wells, pseudomorphic and relaxed layers.","authors":"V A Timofeev, I V Skvortsov, V I Mashanov, A A Bloshkin, I D Loshkarev, V V Kirienko, T M Zalyalov, K A Lozovoy","doi":"10.1088/1361-6528/ada9a6","DOIUrl":"10.1088/1361-6528/ada9a6","url":null,"abstract":"<p><p>Structural and photoelectric properties of p-i-n photodiodes based on GeSiSn/Si multiple quantum dots (QDs) both on Si and silicon-on-insulator substrates were investigated. Elastic strained state of grown films was demonstrated by x-ray diffractometry. Annealing of p-i-n structures before the mesa fabrication can improve the ideality factor of current-voltage characteristics. The lowest dark current density of p-i-n photodiodes based on QDs at the reverse bias of 1 V reaches the value of 0.8 mA cm^-2. The cutoff wavelength shifts to the long-wavelength region with the Sn content increase. Maximum cutoff wavelength value is found to be 2.6<i>μ</i>m. Moreover, multilayer periodic structures with GeSiSn/Ge quantum wells and GeSiSn relaxed layers on Ge substrates were obtained. Reciprocal space maps were used to study the strained state of GeSiSn layers. The optimal growth parameters were determined to obtain slightly relaxed GeSiSn layers. Designed p-i-n photodiodes based on these structures demonstrated the minimal dark current density of 0.7 mA cm^-2and the cutoff wavelength of about 2<i>μ</i>m.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143008795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spontaneous heat current and ultra-high thermal rectification in asymmetric graphene: a molecular dynamics simulation.","authors":"Farrokh Yousefi, Omid Farzadian, Mehdi Shafiee","doi":"10.1088/1361-6528/ada9a5","DOIUrl":"10.1088/1361-6528/ada9a5","url":null,"abstract":"<p><p>Non-equilibrium molecular dynamics simulations reveal the existence of a spontaneous heat current (SHC) in the absence of a temperature gradient and demonstrate ultra-high thermal rectification in asymmetric trapezoid-shaped graphene. These unique properties have potential applications in power generation and thermal circuits, functioning as thermal diodes. Our findings also show the presence of negative and zero thermal conductivity in this system. The negative thermal conductivity could enable the design of a conductive heat machine that pumps heat from the cold side to the hot side without additional energy consumption, functioning as a 'full-free refrigerator'. Meanwhile, zero thermal conductivity paves the way for the development of high-efficiency thermoelectric devices. Simulations were performed in two scenarios: with hydrogenated edges and without them. To ensure the reliability of the results, Reactive Empirical Bond Order and Tersoff potentials were employed. Finally, we examined how the SHC and the temperature difference at which the heat current is zero depend on the sample length, system width, and system temperature.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143008806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bimetallic AuPd alloy nanoparticles on TiO₂ nanotube arrays: a highly efficient photocatalyst for hydrogen generation.","authors":"Harshitha Rajashekhar, Damini Vrushabendrakumar, Md Masud Rana, Kazi Mohammad Alam, Reitesh Kv Raman, Charlin Xinhong Li, Narendra Chaulagain, Karthik Shankar","doi":"10.1088/1361-6528/adb15f","DOIUrl":"https://doi.org/10.1088/1361-6528/adb15f","url":null,"abstract":"<p><p>Decoration of TiO2 nanotube (TNT) arrays by AuPd nanoparticles (NPs) produces a dramatic enhancement in the rate of hydrogen generation through photocatalytic water-splitting under solar illumination. XRD and TEM confirmed alloy formation in bimetallic AuPd NPs while XPS ruled out a core-shell architecture in the AuPd NPs. Well-dispersed, size-controlled AuPd NPs were formed by sequential physical vapor deposition of Au and Pd on TNTs followed by spontaneous thermal dewetting (TNT-AuPd). TNT-AuPd samples were characterized by small tensile microstrains. For comparison purposes and to derive physical insights, an identical method was used to form TNT-Au and TNT-Pd samples wherein TNTs were decorated by monometallic Au and Pd NPs respectively. In every case, an accumulation-type heterointerface between TiO2 and the metallic/bimetallic NPs was indicated by binding energy shifts in the Ti2p high resolution x-ray photoelectron spectra (HR-XPS). Initial and final state effects in the Au4f HR-XPS pointed to a large number of Au atoms in low coordinate sites such as edges, kinks and corners as well as a slower excited atom relaxation in the alloy. A similar preponderance of Pd atoms at low coordinate sites was found along with the presence of a small amount of palladium oxide. TNT-AuPd demonstrated the highest photocatalytic H₂ production rate of 2920 µmol g⁻¹ h⁻¹, which is 8.9 times higher than that of TNTs, 2.1 times that of TNT-Au, and 1.69 times that of TNT-Pd under solar illumination. We studied H₂ generation under UV-filtered solar illumination with TNT-AuPd outperforming monometallic Au- and Pd-NP decorated TNTs, which is attributed to the enhancement of the catalytic activity of Pd in an Au environment, the presence of Pd and Au atoms at low coordinate sites, and photoinduced electron transfer between TNTs and AuPd alloy NPs, where AuPd acts as an efficient electron sink, in turn reducing carrier recombination losses.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143123266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Percolation theory-based KMC simulation for scaled Fe-FET based multi-bit computing-in-memory with temperature compensation strategy.","authors":"Qingxiao Zhu, Lihua Xu, Zhidao Zhou, Wei Wei, Pan Xv, Chunmeng Dou, Lingfei Wang, Qing Luo, Ling Li","doi":"10.1088/1361-6528/ada4b8","DOIUrl":"10.1088/1361-6528/ada4b8","url":null,"abstract":"<p><p>In this letter, we investigate the impact of percolation transport mechanisms on ferroelectric field effect transistor (FeFET) multi-value storage with kinetic Monte-Carlo (KMC) simulation considering aspect ratio and temperature dependencies. It is found that the portion of the ferroelectric polarization, which dominates the threshold voltage shift of the FeFET, increases when aspect ratio of device decreases. Moreover, randomness of percolation path formation and variations of equivalent conductance can be suppressed, indicating mitigation of device-to-device variations and enhancement of separation of individual states. Besides, to further investigate an amorphous channel promising in multi-bit applications, disorder effects in channel contribute to intrinsic percolation transport, coupling with multi-domain dynamics in Fe-layer, are studied by the high temperature characterization. On this basis, the KMC scheme is further modified to predict multi-value distribution from 300 K to 400 K. To tackle such critical reliability issues induced inaccuracy for in-memory computing (CIM), an efficient write-verify scheme is proposed to mitigate state overlapping and provide in-depth insights for co-design of device reliability and multi-bit CIM performances.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142920590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Serum metabolic fingerprinting on Ag@AuNWs for traumatic brain injury diagnosis.","authors":"Jing-Ling Qiang, Yan-Ling Liu, Jian Zhu","doi":"10.1088/1361-6528/ada9f2","DOIUrl":"10.1088/1361-6528/ada9f2","url":null,"abstract":"<p><p>Accurate and rapid diagnosis of traumatic brain injury (TBI) is very important for high quality medical services. Nonetheless, the current diagnostic platform still has challenges in the rapid and accurate analysis of clinical samples. Here, we prepared a highly stable, repeatable and sensitive gold-plated silver core-shell nanowire (Ag@AuNWs) for surface-enhanced Raman spectroscopy (SERS) metabolic fingerprint diagnosis of TBI. The core-shell structure significantly enhanced SERS intensity and enables the direct detection of 10<i>μ</i>l serum within seconds. The principal component analysis-linear discriminant analysis (PCA-LDA) and partial least squares-DA (PLS-DA) are used to evaluate the classification effect of this technology on TBI, respectively. The diagnosis accuracy rate of PCA-LDA and PLS-DA is 73.3% and 86.7% for diagnosing TBI, respectively. Consequently, the PLS-DA model is the optimal selection for distinguishing between the TBI and sham groups. This research will facilitate the application-oriented creation of novel materials with tailored structural designs and the formulation of innovative precision medical protocols in the imminent future.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142984195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent advances in graphitic carbon nitride-based nanocomposites for energy storage and conversion applications.","authors":"Shuxian Tang, Yiwen Xing, Yan Wang, Gang Wei","doi":"10.1088/1361-6528/adad7c","DOIUrl":"10.1088/1361-6528/adad7c","url":null,"abstract":"<p><p>Graphitic carbon nitride (g-C₃N₄) has gained significant attention as a promising nonmetallic semiconductor photocatalyst due to its photochemical stability, favorable electronic properties, and efficient light absorption. Nevertheless, its practical applications are hindered by limitations such as low specific surface area, rapid recombination of photogenerated charge carriers, poor electrical conductivity, and restricted photo-response ranges. This review explores recent advancements in the synthesis, modification and application of g-C₃N₄and its nanocomposites with a focus on addressing these challenges. Key strategies for enhancing g-C₃N₄include various synthesis methods (solvothermal, microwave-assisted, sol-gel, and vapor deposition), doping, defect engineering, heterojunction formation, and surface modifications. Their potential in energy storage and conversion applications, including photocatalytic hydrogen production, carbon dioxide reduction, nitrogen fixation, and electrochemical energy storage are also highlighted. Overall, the review underscores the importance of structural and morphological modifications in improving the photoelectrochemical performance of g-C₃N₄-based nanocomposites, providing insights for future development and optimization.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143029229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hybrid combination of advanced oxidation process with membrane technology for wastewater treatment: gains and problems.","authors":"Chhabilal Regmi, Yuwaraj Khatri Kshetri, S Ranil Wickramasinghe","doi":"10.1088/1361-6528/adb040","DOIUrl":"https://doi.org/10.1088/1361-6528/adb040","url":null,"abstract":"<p><p>Over the past few decades, significant efforts have been dedicated to advancing technologies for the removal of micropollutants from water. Achieving complete pure water with a single treatment process is challenging and nearly impossible. One promising approach among various alternatives is adopting hybrid technology, which is considered as a win-win technology. It utilizes the advantages of each technique, resulting in the enhancement of wastewater treatment. This pioneering idea is designed to significantly enhance water quality, addressing real-world implementation hurdles, and offer a promising solution to the worldwide issue of water scarcity. This review assesses the merits and drawbacks of the hybrid photocatalytic membrane technology employed in wastewater treatment. Notably, this hybrid process not only improves the membrane filtration capacity and permeates water quality but also enhances the antifouling performance of the membrane. However, it is crucial to acknowledge potential drawbacks, such as membrane structure degradation and photocatalytic activity loss in nanoparticles during the operation period. While improvements in wastewater treatment efficiency are evident, there remains ample room for further enhancements. The review summarizes the future directions and challenges of implementing such an integrated system.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143066857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Targeted therapy for glioblastoma utilizing hyaluronic acid-engineered liposomes for adriamycin delivery.","authors":"Yanping Wang, Peiyan Qi, Shenbao Shi, Cong Pang, Weijie Wang, Dazhao Fang","doi":"10.1088/1361-6528/adacef","DOIUrl":"10.1088/1361-6528/adacef","url":null,"abstract":"<p><p>Glioblastoma (GBM) is a malignant tumor with highly heterogeneous and invasive characteristics leading to a poor prognosis. The CD44 molecule, which is highly expressed in GBM, has emerged as a highly sought-after biological marker. Therapeutic strategies targeting the cell membrane protein CD44 have emerged, demonstrating novel therapeutic potential. In this study, we constructed a nanodrug system (HA-Liposome@Dox) based on hyaluronic acid-engineered liposomes delivering adriamycin to target GBM. The system efficiently encapsulated Dox inside the liposomes through a hydrophilic-hydrophobic interaction mechanism, and the resulting HA-Liposome@Dox exhibited excellent loading efficacy, attributed to its uniform particle size distribution and negatively charged surface. Further evaluation revealed that HA-Liposome@Dox possessed excellent stability and safety and could promote the effective uptake of drug particles by CD44-overexpressing tumor cells, thus exerting a more potent cell-killing effect. Notably, in the treatment of GBM, HA-Liposome@Dox demonstrated significantly greater tumor growth inhibition compared to free Dox and prolonged the survival of tumor-bearing mice. Taken together, the present study not only verified the feasibility of HA-Liposome@Dox as an effective therapeutic tool against GBM and other CD44-positively expressing tumors, but also opened a promising new avenue for the clinical treatment of this type of refractory malignancies.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143024208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}