Nanotechnology最新文献

{"title":"Estimation of local variation in Young's modulus over a gold nanocontact using microscopic nanomechanical measurement method.","authors":"Jiaming Liu, Jiaqi Zhang, Kohei Aso, Toyoko Arai, Masahiko Tomitori, Yoshifumi Oshima","doi":"10.1088/1361-6528/ad83d6","DOIUrl":"10.1088/1361-6528/ad83d6","url":null,"abstract":"<p><p>Nanoscale materials tend to have a single crystal domain, leading to not only size dependence but also orientation dependence of their mechanical properties. Recently, we developed a microscopic nanomechanical measurement method (MNMM), which enabled us to obtain equivalent spring constants (force gradients) of nanocontacts (NCs) while observing their atomic structures by transmission electron microscopy (TEM). Therein, we evaluated Young's modulus based on a model that a newly introduced layer at the thinnest section of a NC determined the change in the measured equivalent spring constant, and discussed their size dependence. However, this model is not general for other nanomaterials that do not exhibit the introduction of a new atomic layer while stretching. In this study, using MNMM, we propose a new analytical method to directly retrieve the local Young's modulus of nanomaterials by measuring initial lattice spacing and its displacement of a local region in the TEM image during the stretching of the NC. This reveals the size dependence of local Young's modulus at various positions of the NC at once. As a result, our estimated Young's modulus for a gold [111] NC showed a size dependence similar to the one previously reported. This indicates that this analytical method benefits in revealing the mechanical properties of not only nanomaterials but also structurally heterogeneous materials such as high-entropy alloys.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142391988","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":"Study on the effects of strain and electrostatic doping on the magnetic anisotropy of GaN/VTe₂van der waals heterostructure.","authors":"Junjun Xue, Wei Chen, Shanwen Hu, Zhouyu Chen, Haoyu Fang, Ting Zhi, Pengfei Shao, Qing Cai, Guofeng Yang, Yan Gu, Jin Wang, Dunjun Chen","doi":"10.1088/1361-6528/ad8450","DOIUrl":"10.1088/1361-6528/ad8450","url":null,"abstract":"<p><p>Using a first-principles approach, this study delves into the effects of strain and electrostatic doping on the electronic and magnetic properties of the GaN/VTe₂van der Waals (vdW) heterostructure. The results reveal that when the GaN/VTe₂vdW heterostructure is doped with 0.1<i>h</i>/0.2<i>h</i>of electrostatic charge, its magnetization direction undergoes a remarkable reversal, shifting from out-of-plane orientation to in-plane direction. Therefore, we conduct a thorough investigation into the influence of electron orbitals on magnetic anisotropy energy. In addition, as the strain changes from -1% to 1%, the 100% spin polarization region of the GaN/VTe₂vdW heterostructure becomes smaller. It is worth noting that at a doping concentration of 0.1<i>h</i>, the GaN/VTe₂vdW heterostructure has a Curie temperature of 30 K above room temperature. This comprehensive study provides valuable insights and provides a reference for analyzing the electronic and magnetic properties of low-dimensional systems.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142391995","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":"Electric field simulation, structure and properties of nanofiber- coated yarn prepared by multi-needle water bath electrospinning.","authors":"Xiaohu Wang, Xinru Zhou, Xiaoman Zhao, Xiao Han, Jianhan Hong","doi":"10.1088/1361-6528/ad8422","DOIUrl":"10.1088/1361-6528/ad8422","url":null,"abstract":"<p><p>To address the issue of low yield in the preparation of nanofiber materials using single-needle electrospinning technology, multi-needle electrospinning technology has emerged as a crucial solution for mass production. However, the mutual interference of multiple electric fields between the needles can cause significant randomness in the morphology of the produced nanofibers. To better predict the influence of electric field distribution on nanofiber morphology, simulation analysis of the multi-needle arrangement was conducted using finite element analysis (FEA) software. Nanofiber-coated yarn was produced continuously with the core yarn rotating. The water bath was utilized as the receiver of nanofibers on self-made water bath electrospinning equipment. The electric field distribution and mutual interference under seven different needle arrangements was simulated and analyzed by FEA software ANSYS Maxwell. The results indicated that when the needles were arranged diagonally in a staggered pattern and directly above the core yarn, the simulated electric field distribution was relatively uniform, with less mutual interference. The produced nanofibers exhibited a finer diameter and the diameter distribution was more concentrated. In addition, the nanofiber coating showed higher crystallinity and better mechanical properties.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142391986","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":"Engineering Fano resonances in plasmonic metasurfaces for colorimetric sensing and structural colors.","authors":"Reza Kohandani, Simarjeet Singh Saini","doi":"10.1088/1361-6528/ad83d7","DOIUrl":"10.1088/1361-6528/ad83d7","url":null,"abstract":"<p><p>In this paper, we present the design and fabrication of a plasmonic metasurface based on titanium dioxide (TiO₂) nanowire arrays integrated with plasmonic layers. The structure is engineered to produce Fano resonances within the visible spectrum, resulting from the coupling of localized surface plasmon resonances, lattice modes, and nanowire's optical modes. Experimentally, we show that by tuning the geometrical features of the metasurface, such as the length, diameter, and period of the nanowires, a high-quality factor single peak can be achieved in the reflection spectra, resulting in vivid structural colors in bright field. To our knowledge, this is the first demonstration of such vivid colors with nanowire arrays in bright field reflections. When characterized by refractive index fluids around the refractive index of water, the plasmonic metasurface also showed great potential for biochemical colorimetric sensing. The best design demonstrated a bulk sensitivity of 183 nm/RIU with high Q resonance features and linear changes in color values using image processing.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142391987","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":"Effect of anisotropy and length dispersity on electrical and optical properties of nanowire network based transparent electrodes: a computational study.","authors":"Yugam Bharti, Vikas Malik, Preeti Bhandari, Shruti Aggarwal","doi":"10.1088/1361-6528/ad8166","DOIUrl":"10.1088/1361-6528/ad8166","url":null,"abstract":"<p><p>We have studied the impact of nanowire alignment and measurement direction at the percolation threshold on the effective resistance (<i>R</i>) of two-dimensional (2D) films. This helps us to analyze the effect of anisotropy on the conductivity and transmittance of the nanowire-based network characterized by the disorder parameter (<i>s</i>). These optoelectronic properties are determined for systems with monodisperse and bimodal length distribution (a combination of two fixed lengths of nanowires). The 2D systems simulated using our computational approach are assumed to be transparent and conductive in which percolative transport is the primary conduction mechanism. We obtain our results numerically using a computational and geometrical approach, i.e. a Discrete (grid) method that is advantageous in algorithm speed. For a particular disorder parameter<i>s</i>, the conductivity and transmittance increase as the length fraction (<i>LF</i>) increases for the bimodal distribution of the length of nanowires in networks. We have observed the maximum conductivity when the nanowires are highly aligned along the measurement direction of percolation, in contrast to the isotropic arrangement of nanowires. Significantly, alignment introduced in nanowires leads to a higher percolation threshold which leads to a decrease in the transmittance of the network. We show that the resistivity of the monodisperse network in the direction parallel (perpendicular) to the alignment decreases (increases) with the disorder parameter and scales as<i>s</i>(<i>s</i>²). This scaling holds true for the bimodal distribution of nanowires as well. For a particular<i>LF</i>, the electrical anisotropy increases with<i>s</i>. The anisotropy is maximum for nearly aligned nanowires in a bimodal network with the highest proportion of the longest wire considered. For the maximally aligned wires and highest<i>LF</i>, we obtained an approximately 50%enhancement in the figure of merit, denoted by<i>φ</i>. Hence, incorporating longer-length wires and increasing the alignment in nanowire networks can increase the conductivity, anisotropy, and figure of merit which may benefit a vast range of applications.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142350570","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":"Enhancement of photoresponse for InGaAs infrared photodetectors using plasmonic WO3-x/Cs_<i>y</i>WO3-xnanocrystals.","authors":"Zach D Merino, Gyorgy Jaics, Andrew W M Jordan, Arjun Shetty, Penghui Yin, Man C Tam, Xinning Wang, Zbig R Wasilewski, Pavle V Radovanovic, Jonathan Baugh","doi":"10.1088/1361-6528/ad82f1","DOIUrl":"10.1088/1361-6528/ad82f1","url":null,"abstract":"<p><p>Fast and accurate detection of light in the near-infrared (NIR) spectral range plays a crucial role in modern society, from alleviating speed and capacity bottlenecks in optical communications to enhancing the control and safety of autonomous vehicles through NIR imaging systems. Several technological platforms are currently under investigation to improve NIR photodetection, aiming to surpass the performance of established III-V semiconductor p-i-n (PIN) junction technology. These platforms include<i>in situ</i>-grown inorganic nanocrystals (NCs) and nanowire arrays, as well as hybrid organic-inorganic materials such as graphene-perovskite heterostructures. However, challenges remain in NC and nanowire growth, large-area fabrication of high-quality 2D materials, and the fabrication of devices for practical applications. Here, we explore the potential for tailored semiconductor NCs to enhance the responsivity of planar metal-semiconductor-metal (MSM) photodetectors. MSM technology offers ease of fabrication and fast response times compared to PIN detectors. We observe enhancement of the optical-to-electric conversion efficiency by up to a factor of ∼2.5 through the application of plasmonically-active semiconductor nanorods and NCs. We present a protocol for synthesizing and rapidly testing the performance of non-stoichiometric tungsten oxide (WO3-x) nanorods and cesium-doped tungsten oxide (Cs_<i>y</i>WO3-x) hexagonal nanoprisms prepared in colloidal suspensions and drop-cast onto photodetector surfaces. The results demonstrate the potential for a cost-effective and scalable method exploiting tailored NCs to improve the performance of NIR optoelectronic devices.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142372363","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":"Fabrication and characterization of bioresorbable, electroactive and highly regular nanomodulated cell interfaces.","authors":"Alice Lunghi, Federica Velluto, Luana Di Lisa, Matteo Genitoni, Fabio Biscarini, Maria Letizia Focarete, Chiara Gualandi, Michele Bianchi","doi":"10.1088/1361-6528/ad8096","DOIUrl":"10.1088/1361-6528/ad8096","url":null,"abstract":"<p><p>Biomaterial-based implantable scaffolds capable of promoting physical and functional reconnection of injured spinal cord and nerves represent the latest frontier in neural tissue engineering. Here, we report the fabrication and characterization of self-standing, biocompatible and bioresorbable substrates endowed with both controlled nanotopography and electroactivity, intended for the design of transient implantable scaffolds for neural tissue engineering. In particular, we obtain conductive and nano-modulated poly(D,L-lactic acid) (PLA) and poly(lactic-<i>co</i>-glycolic acid) free-standing films by simply iterating a replica moulding process and coating the polymer with a thin layer of poly(3,4-ethylendioxythiophene) polystyrene sulfonate. The capability of the substrates to retain both surface patterning and electrical properties when exposed to a liquid environment has been evaluated by atomic force microscopy, electrochemical impedance spectroscopy and thermal characterizations. In particular, we show that PLA-based films maintain their surface nano-modulation for up to three weeks of exposure to a liquid environment, a time sufficient for promoting axonal anisotropic sprouting and growth during neuronal cell differentiation. In conclusion, the developed substrates represent a novel and easily-tunable platform to design bioresorbable implantable devices featuring both topographic and electrical cues.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142350572","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":"Low temperature atomic layer deposition of PbO₂for electrochemical applications.","authors":"Ashley R Bielinski, Jonathan D Emery, Frederick Agyapong-Fordjour, Jessica Jones, Pietro Papa Lopes, Alex B F Martinson","doi":"10.1088/1361-6528/ad8163","DOIUrl":"https://doi.org/10.1088/1361-6528/ad8163","url":null,"abstract":"<p><p>A low temperature atomic layer deposition (ALD) process for PbO₂was developed using bis(1-dimethylamino-2-methyl-2-propanolate)lead(II), Pb(DMAMP)₂, and O₃as the reactants, with a high growth rate of 2.6 Å/cycle. PbO₂readily reduces under low oxygen partial pressures at moderate temperatures making it challenging to deposit ALD PbO₂from Pb²⁺precursors. However, thin films deposited with this process showed small crystalline grains of α-PbO₂and β-PbO₂, without signs of reduced PbO<i>_x</i>phases. The ALD PbO₂thin films show the high electrical conductivity characteristic of bulk PbO₂. In situ measurements of ALD PbO₂film conductivity during growth suggest a reaction mechanism by which sub-surface oxygen mobility contributes to the growth of resistive PbO or PbO<i>_x</i>during the Pb(DMAMP)₂surface reaction step, which is only fully oxidized from Pb²⁺to Pb⁴⁺during the O₃reaction step. These films were electrochemically reduced to PbSO₄in H₂SO₄and then reoxidized to PbO₂, demonstrating their suitability for use as an electrode material for fundamental battery research and other electrochemical applications.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":"35 50","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142400820","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":"Robust topological insulating property in C₂X-functionalized III-V monolayers.","authors":"Xianghong Xue, Zhihua Lin, Rui Gao, Bingzhuo Yang, Haoyu Wang, Mengmeng Han, Nannan Han","doi":"10.1088/1361-6528/ad8098","DOIUrl":"10.1088/1361-6528/ad8098","url":null,"abstract":"<p><p>Two-dimensional topological insulators (TIs) show great potential applications in low-power quantum computing and spintronics due to the spin-polarized gapless edge states. However, the small bandgap limits their room-temperature applications. Based on first-principles calculations, a series of C₂X (X = H, F, Cl, Br and I) functionalized III-V monolayers are investigated. The nontrivial bandgaps of GaBi-(C₂X)₂, InBi-(C₂X)₂, TlBi-(C₂X)₂and TlSb-(C₂X)₂are found to between 0.223 and 0.807 eV. For GaBi-(C₂X)₂and InBi-(C₂X)₂, the topological insulating properties originate from the<i>s-px,y</i>band inversion induced by the spin-orbital coupling (SOC) effect. While for TlBi-(C₂X)₂and TlSb-(C₂X)₂, the topological insulating properties are attributed to the SOC effect-induced band splitting. The robust topological characteristics are further confirmed by topological invariants<i>Z</i>₂and the test under biaxial strain. Finally, two ideal substrates are predicted to promote the applications of these TIs. These findings indicate that GaBi-(C₂X)₂, InBi-(C₂X)₂, TlBi-(C₂X)₂and TlSb-(C₂X)₂monolayers are good candidates for the fabrication of spintronic devices.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142350577","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":"Tailoring efficient manganese bromide-based scintillator films with ethyl acetate assistance.","authors":"Kun Zhou, Muhammad Bilal, Kaiyu Xia, Yuting Xie, Ting Chen, Xiaofeng Hu, Xiuyuan Chen, Chenchen Yang, Shicheng Pan, Gang Xu, Xinxin Miao, Qingquan He, He Tengyue, Omar F Mohammed, Jun Pan","doi":"10.1088/1361-6528/ad8580","DOIUrl":"https://doi.org/10.1088/1361-6528/ad8580","url":null,"abstract":"<p><p>Metal halide scintillators serve as a compelling substitute for traditional scintillators in X-ray detection and imaging due to their low-temperature fabrication process, high light yield and mechanical flexibility. Nevertheless, the spatial resolution and photoluminescence quantum yield (PLQY) of these films are hindered by the agglomeration and uneven distribution of metal halides crystal particles during the fabrication process. We introduce a modified fabrication approach for metal halide scintillator films involving an additional step of ethyl acetate (EA) treatment, resulting in the preparation of a smooth EA-treated (Ph4P)2MnBr4/Polydimethylsiloxane film. The carbonyl groups within EA interact with elements of the (Ph4P)2MnBr4 microcrystals powder, ensuring uniform dispersion and preventing agglomeration. The EA-treated composite film demonstrates a remarkable PLQY of approximately 95% and an impressive spatial resolution of 14 lp/mm, with enhanced stability under harsh environments. These characteristics ensure its suitability as a high-performance X-ray imaging scintillator.&#xD.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142400818","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}