{"title":"Electrical characterization of an individual nanowire using flexible nanoprobes fabricated by atomic force microscopy-based manipulation","authors":"Yilin Wang, Enxiu Wu, Jirui Liu, Mengke Jia, Rui Zhang, Sen Wu","doi":"10.1063/10.0021195","DOIUrl":"https://doi.org/10.1063/10.0021195","url":null,"abstract":"Nanowires have emerged as promising one-dimensional materials with which to construct various nanocircuits and nanosensors. However, measuring the electrical properties of individual nanowires directly remains challenging because of their small size, thereby hindering the comprehensive understanding of nanowire-based device performance. A crucial factor in achieving reliable electrical characterization is establishing well-determined contact conditions between the nanowire sample and the electrodes, which becomes particularly difficult for soft nanowires. Introduced here is a novel technique for measuring the conductivity of an individual nanowire with the aid of automated nanomanipulation using an atomic force microscope. In this method, two nanowire segments cut from the same silver nanowire are positioned onto a pair of gold electrodes, serving as flexible nanoprobes to establish controllable contact with the sample. By changing the contact points along the nanowire sample, conductivity measurements can be performed on different regions, thereby eliminating the influence of contact resistance by analyzing multiple current–voltage curves. Using this approach, the resistivity of a 100-nm-diameter silver nanowire is determined to be 3.49 × 10−8 Ω m.","PeriodicalId":87330,"journal":{"name":"Nanotechnology and Precision Engineering","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135967657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Nanostructure enabled extracellular vesicles separation and detection","authors":"Xinyuan He, Wei Wei, Xuexin Duan","doi":"10.1063/10.0020885","DOIUrl":"https://doi.org/10.1063/10.0020885","url":null,"abstract":"Extracellular vesicles (EVs) have recently attracted significant research attention owing to their important biological functions, including cell-to-cell communication. EVs are a type of membrane vesicles that are secreted into the extracellular space by most types of cells. Several biological biomolecules found in EVs, such as proteins, microRNA, and DNA, are closely related to the pathogenesis of human malignancies, making EVs valuable biomarkers for disease diagnosis, treatment, and prognosis. Therefore, EV separation and detection are prerequisites for providing important information for clinical research. Conventional separation methods suffer from low levels of purity, as well as the need for cumbersome and prolonged operations. Moreover, detection methods require trained operators and present challenges such as high operational expenses and low sensitivity and specificity. In the past decade, platforms for EV separation and detection based on nanostructures have emerged. This article reviews recent advances in nanostructure-based EV separation and detection techniques. First, nanostructures based on membranes, nanowires, nanoscale deterministic lateral displacement, and surface modification are presented. Second, high-throughput separation of EVs based on nanostructures combined with acoustic and electric fields is described. Third, techniques combining nanostructures with immunofluorescence, surface plasmon resonance, surface-enhanced Raman scattering, electrochemical detection, or piezoelectric sensors for high-precision EV analysis are summarized. Finally, the potential of nanostructures to detect individual EVs is explored, with the aim of providing insights into the further development of nanostructure-based EV separation and detection techniques.","PeriodicalId":87330,"journal":{"name":"Nanotechnology and Precision Engineering","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135388632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiuhong Wang , Junlei Zhao , Zongwei Xu , Flyura Djurabekova , Mathias Rommel , Ying Song , Fengzhou Fang
{"title":"Density functional theory calculation of the properties of carbon vacancy defects in silicon carbide","authors":"Xiuhong Wang , Junlei Zhao , Zongwei Xu , Flyura Djurabekova , Mathias Rommel , Ying Song , Fengzhou Fang","doi":"10.1016/j.npe.2020.11.002","DOIUrl":"10.1016/j.npe.2020.11.002","url":null,"abstract":"<div><p>As a promising material for quantum technology, silicon carbide (SiC) has attracted great interest in materials science. Carbon vacancy is a dominant defect in 4H-SiC. Thus, understanding the properties of this defect is critical to its application, and the atomic and electronic structures of the defects needs to be identified. In this study, density functional theory was used to characterize the carbon vacancy defects in hexagonal (h) and cubic (k) lattice sites. The zero-phonon line energies, hyperfine tensors, and formation energies of carbon vacancies with different charge states (2<sup>−</sup>, <sup>−</sup>, 0, <sup>+</sup> and 2<sup>+</sup>) in different supercells (72, 128, 400 and 576 atoms) were calculated using standard Perdew–Burke–Ernzerhof and Heyd–Scuseria–Ernzerhof methods. Results show that the zero-phonon line energies of carbon vacancy defects are much lower than those of divacancy defects, indicating that the former is more likely to reach the excited state than the latter. The hyperfine tensors of V<sub>C</sub><sup>+</sup>(h) and V<sub>C</sub><sup>+</sup>(k) were calculated. Comparison of the calculated hyperfine tensor with the experimental results indicates the existence of carbon vacancies in SiC lattice. The calculation of formation energy shows that the most stable carbon vacancy defects in the material are V<sub>C</sub><sup>2+</sup>(k), V<sub>C</sub><sup>+</sup>(k), V<sub>C</sub>(k), V<sub>C</sub><sup>−</sup>(k) and V<sub>C</sub><sup>2−</sup>(k) as the electronic chemical potential increases.</p></div>","PeriodicalId":87330,"journal":{"name":"Nanotechnology and Precision Engineering","volume":"3 4","pages":"Pages 211-217"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2589554020300374/pdfft?md5=3aaca7d6e5e6a8f4634f79bafa2b0bc0&pid=1-s2.0-S2589554020300374-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48126822","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}
{"title":"Investigation of material removal characteristics of Si (100) wafer during linear field atmospheric-pressure plasma etching","authors":"Weijia Guo , Senthil Kumar A. , Peng Xu","doi":"10.1016/j.npe.2020.09.003","DOIUrl":"10.1016/j.npe.2020.09.003","url":null,"abstract":"<div><p>Atmospheric-pressure (AP) plasma etching provides an alternative method for mechanical grinding to realize wafer thinning of Si wafer. It can avoid the damages and micro-cracks that would be introduced by mechanical stress during the grinding process. In this study, the material removal characteristics of Si (100) wafer processed by linear field AP plasma generated using carbon tetrafluoride (CF<sub>4</sub>) as the reactive source were analyzed. This linear field plasma etching tool has a typical removal profile and the depth removal rate that can reach up to 1.082 μm/min. The effect of O<sub>2</sub> concentration on the removal rate was discussed and the surface morphology during the process was characterized using scanning electron microscopy. It is shown that the subsurface damage layer was gradually removed during the etching process and the surface was observed to be smoothened with the increase of the etching depth. This present work contributes a basic understanding of the linear field AP plasma etching performance with different gas composition and the typical characteristics would be further applied to damage-free precision removal of Si.</p></div>","PeriodicalId":87330,"journal":{"name":"Nanotechnology and Precision Engineering","volume":"3 4","pages":"Pages 244-249"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.npe.2020.09.003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47765042","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}
Yongle Qi , Denggui Wang , Jianjun Zhou , Kai Zhang , Yuechan Kong , Suzhen Wu , Tangsheng Chen
{"title":"Effect of X-ray irradiation on threshold voltage of AlGaN/GaN HEMTs with p-GaN and MIS Gates","authors":"Yongle Qi , Denggui Wang , Jianjun Zhou , Kai Zhang , Yuechan Kong , Suzhen Wu , Tangsheng Chen","doi":"10.1016/j.npe.2020.11.001","DOIUrl":"10.1016/j.npe.2020.11.001","url":null,"abstract":"<div><p>Commercially available AlGaN/GaN high-electron-mobility transistors (HEMTs) are beginning to enter the public scene from a range of suppliers. Based on previous studies, commercial GaN-based electronics are expected to be tolerant to different types of irradiation in space. To test this assumption, we compared the characteristic electrical curves obtained at different X-ray irradiation doses for GaN HEMT devices manufactured by Infineon and Transphorm. The p-GaN-based device was found to be more robust with a stable threshold voltage, whereas the threshold voltage of the device with a metal-insulator-semiconductor gate was found to shift first in the negative and then the positive direction. This dynamic phenomenon is caused by the releasing and trapping effects of radiation-induced charges in the dielectric layer and at the interface of irradiated devices. As such, the p-GaN-gate-based GaN HEMT provides a promising solution for use as an electric source in space.</p></div>","PeriodicalId":87330,"journal":{"name":"Nanotechnology and Precision Engineering","volume":"3 4","pages":"Pages 241-243"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.npe.2020.11.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47185051","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}
Wenge Chen , Tao Yang , Longlong Dong , Ahmed Elmasry , Jiulong Song , Nan Deng , Ahmed Elmarakbi , Terence Liu , Hai Bao Lv , Yong Qing Fu
{"title":"Advances in graphene reinforced metal matrix nanocomposites: Mechanisms, processing, modelling, properties and applications","authors":"Wenge Chen , Tao Yang , Longlong Dong , Ahmed Elmasry , Jiulong Song , Nan Deng , Ahmed Elmarakbi , Terence Liu , Hai Bao Lv , Yong Qing Fu","doi":"10.1016/j.npe.2020.12.003","DOIUrl":"10.1016/j.npe.2020.12.003","url":null,"abstract":"<div><p>Graphene has been extensively explored to enhance functional and mechanical properties of metal matrix nanocomposites for wide-range applications due to their superior mechanical, electrical and thermal properties. This article discusses recent advances of key mechanisms, synthesis, manufacture, modelling and applications of graphene metal matrix nanocomposites. The main strengthening mechanisms include load transfer, Orowan cycle, thermal mismatch, and refinement strengthening. Synthesis technologies are discussed including some conventional methods (such as liquid metallurgy, powder metallurgy, thermal spraying and deposition technology) and some advanced processing methods (such as molecular-level mixing and friction stir processing). Analytical modelling (including phenomenological models, semi-empirical models, homogenization models, and self-consistent model) and numerical simulations (including finite elements method, finite difference method, and boundary element method) have been discussed for understanding the interface bonding and performance characteristics between graphene and different metal matrices (Al, Cu, Mg, Ni). Key challenges in applying graphene as a reinforcing component for the metal matrix composites and the potential solutions as well as prospectives of future development and opportunities are highlighted.</p></div>","PeriodicalId":87330,"journal":{"name":"Nanotechnology and Precision Engineering","volume":"3 4","pages":"Pages 189-210"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2589554020300416/pdfft?md5=999c2840e0051d104302fd796db39582&pid=1-s2.0-S2589554020300416-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44570037","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}
{"title":"Foreword to the special issue on wide-bandgap (WBG) semiconductors: from fundamentals to applications","authors":"Zongwei Xu , Yidan Tang , Mathias Rommel","doi":"10.1016/j.npe.2021.01.001","DOIUrl":"10.1016/j.npe.2021.01.001","url":null,"abstract":"","PeriodicalId":87330,"journal":{"name":"Nanotechnology and Precision Engineering","volume":"3 4","pages":"Pages 187-188"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2589554021000015/pdfft?md5=73039bce179816b755f02cec23e73fed&pid=1-s2.0-S2589554021000015-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47920090","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}
{"title":"Surface defects in 4H-SiC homoepitaxial layers","authors":"Lixia Zhao","doi":"10.1016/j.npe.2020.12.001","DOIUrl":"10.1016/j.npe.2020.12.001","url":null,"abstract":"<div><p>Although a high-quality homoepitaxial layer of 4H‑silicon carbide (4H-SiC) can be obtained on a 4° off-axis substrate using chemical vapor deposition, the reduction of defects is still a focus of research. In this study, several kinds of surface defects in the 4H-SiC homoepitaxial layer are systemically investigated, including triangles, carrots, surface pits, basal plane dislocations, and step bunching. The morphologies and structures of surface defects are further discussed via optical microscopy and potassium hydroxide-based defect selective etching analysis. Through research and analysis, we found that the origin of surface defects in the 4H-SiC homoepitaxial layer can be attributed to two aspects: the propagation of substrate defects, such as scratches, dislocation, and inclusion, and improper process parameters during epitaxial growth, such as in-situ etch, C/Si ratio, and growth temperature. It is believed that the surface defects in the 4H-SiC homoepitaxial layer can be significantly decreased by precisely controlling the chemistry on the deposition surface during the growth process.</p></div>","PeriodicalId":87330,"journal":{"name":"Nanotechnology and Precision Engineering","volume":"3 4","pages":"Pages 229-234"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2589554020300398/pdfft?md5=320ef4c1022524e3ba5e558efef1a2f1&pid=1-s2.0-S2589554020300398-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44562361","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}
Jiayu Liu , Zongwei Xu , Ying Song , Hong Wang , Bing Dong , Shaobei Li , Jia Ren , Qiang Li , Mathias Rommel , Xinhua Gu , Bowen Liu , Minglie Hu , Fengzhou Fang
{"title":"Confocal photoluminescence characterization of silicon-vacancy color centers in 4H-SiC fabricated by a femtosecond laser","authors":"Jiayu Liu , Zongwei Xu , Ying Song , Hong Wang , Bing Dong , Shaobei Li , Jia Ren , Qiang Li , Mathias Rommel , Xinhua Gu , Bowen Liu , Minglie Hu , Fengzhou Fang","doi":"10.1016/j.npe.2020.11.003","DOIUrl":"10.1016/j.npe.2020.11.003","url":null,"abstract":"<div><p>Silicon-vacancy (V<sub>Si</sub>) centers in silicon carbide (SiC) are expected to serve as solid qubits, which can be used in quantum computing and sensing. As a new controllable color center fabrication method, femtosecond (fs) laser writing has been gradually applied in the preparation of V<sub>Si</sub> in SiC. In this study, 4H-SiC was directly written by an fs laser and characterized at 293 K by atomic force microscopy, confocal photoluminescence (PL), and Raman spectroscopy. PL signals of V<sub>Si</sub> were found and analyzed using 785 nm laser excitation by means of depth profiling and two-dimensional mapping. The influence of machining parameters on the V<sub>Si</sub> formation was analyzed, and the three-dimensional distribution of V<sub>Si</sub> defects in the fs laser writing of 4H-SiC was established.</p></div>","PeriodicalId":87330,"journal":{"name":"Nanotechnology and Precision Engineering","volume":"3 4","pages":"Pages 218-228"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2589554020300386/pdfft?md5=ab855e0159fceaf29f83c7cb62ca47b8&pid=1-s2.0-S2589554020300386-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45040799","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}
Shen Diao , Jun Sun , Ziwei Zhou , Zhenzhong Zhang , Adolf Schöner , Zedong Zheng , Weiwei He
{"title":"Determination of failure degree of 1.2 kV SiC MOSFETs after short-circuit test using an improved test setup","authors":"Shen Diao , Jun Sun , Ziwei Zhou , Zhenzhong Zhang , Adolf Schöner , Zedong Zheng , Weiwei He","doi":"10.1016/j.npe.2020.12.002","DOIUrl":"10.1016/j.npe.2020.12.002","url":null,"abstract":"<div><p>Analysis of the short-circuit characteristics of SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) is very important for their practical application. This paper studies the SiC MOSFET short-circuit characteristics with an improved test setup under different conditions. A high-current Si insulated gate bipolar transistor is used as a circuit breaker in the test circuit rather than the usual short-circuit test conducted without a circuit breaker. The test platform with a circuit breaker does not influence the calculation results regarding the short-circuit withstand time and energy, but the SiC MOSFET will switch off after failure in a very short time. In addition, the degree of failure will be limited and confined to a small area, such that the damage to the chip will be clearly observable, which is significant for short-circuit failure analysis.</p></div>","PeriodicalId":87330,"journal":{"name":"Nanotechnology and Precision Engineering","volume":"3 4","pages":"Pages 235-240"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2589554020300404/pdfft?md5=2d7036ef65c78ea550735181b5d3fd38&pid=1-s2.0-S2589554020300404-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47025502","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}