Journal of Physics D: Applied Physics最新文献

{"title":"Enhancing n-type doping in diamond by strain engineering","authors":"Chunmin Cheng, Xiang Sun, Wei Shen, Qijun Wang, Lijie Li, Fang Dong, Kang Liang, Gai Wu","doi":"10.1088/1361-6463/ad7270","DOIUrl":"https://doi.org/10.1088/1361-6463/ad7270","url":null,"abstract":"The utilization of diamond, the ultimate semiconductor, in electronic devices is challenging due to the difficulty of n-type doping. Phosphorus (P)-doped diamond, the most prevalent type of n-type diamond, is still limited by the low solubility of P dopant and undesirable compensating defects such as vacancy defects and hydrogen incorporation. In order to overcome this limitation, strain engineering is introduced to the n-type P-doped diamond theoretically in this work. Uniaxial, equibiaxial, and hydrostatic triaxial strains are applied to the P-doped diamond. The formation energy, charge transition level, defect binding energy and other physical properties of the P-doped diamond are then calculated based on first-principles calculations. The results show that uniaxial, equibiaxial, and hydrostatic triaxial tensile strain can reduce the formation energy and the donor ionization energy of P dopant, and also reduce the binding energy of phosphorus–vacancy (PV) and phosphorus–hydrogen (PH) defects. Our results indicate that under tensile strain, the solubility of the P dopant and the n-type conductivity of the P-doped diamond can be increased, and the formation of compensating defects can be suppressed. Therefore, strain engineering is anticipated to be used to enhance the n-type characteristics of the P-doped diamond, facilitating its application in electronic devices.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"29 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Defect engineering strategies in monolayer VSe2 for enhanced hydrogen evolution reaction: a computational study","authors":"Rabia Hassan, Fei Ma, Yan Li, Rehan Hassan","doi":"10.1088/1361-6463/ad73e3","DOIUrl":"https://doi.org/10.1088/1361-6463/ad73e3","url":null,"abstract":"Defect engineering is a powerful strategy for enhancing the catalytic properties of monolayer VSe₂. In this work, we used density functional theory (DFT) to investigate the impact of point defects and hydrogen adsorption sites on the hydrogen evolution reaction (HER) activity of VSe₂. We analyzed the formation energies and hydrogen adsorption behavior of single and double vacancies in VSe₂. The results show that V vacancy defect (D2), consecutive V-Se double vacancy defect (D3), and separate V-Se double defect (D4) exhibit the enhanced HER activity with Gibbs free energies (Δ<italic toggle=\"yes\">G</italic>_H* = 0.04 eV, 0.04 eV and 0.06 eV, respectively) even surpassing that of platinum (Δ<italic toggle=\"yes\">G</italic>_H* = − 0.1 eV). This study highlights the potential of defect-engineered VSe₂ for efficient hydrogen evolution.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"61 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Label-free characterization of pathological changes in the portal area of liver fibrosis tissue using multiphoton imaging and quantitative image analysis","authors":"Xiong Zhang, Yuan-E Lian, XunBin Yu, Xingxin Huang, Zheng Zhang, Jingyi Zhang, Jianxin Chen, Lianhuang Li, Yannan Bai","doi":"10.1088/1361-6463/ad73e6","DOIUrl":"https://doi.org/10.1088/1361-6463/ad73e6","url":null,"abstract":"Liver fibrosis plays a crucial role in the progression of liver diseases and serves as a pivotal stage leading to the development of liver cirrhosis and cancer. It typically initiates from portal area with various pathological characteristics. In this article, we employed multiphoton microscopy (MPM) to characterize the pathological changes in the portal areas of liver fibrosis tissues, and subsequently, we used our developed image analysis method to extract eight collagen morphological features from MPM images and also combined a deep learning method with a cell nuclear feature extraction algorithm to perform automatic nuclei segmentation and quantitative analysis in the H&amp;E-stained histopathology images of portal areas. Our results demonstrate that MPM can effectively identify various pathological features in portal areas, and there are significant differences in four collagen features (collagen proportionate area, number, length and width) between normal and abnormal portal areas and in four nuclear features (mean ratio of axial length, disorder of distance to 3, 5 and 7 nearest neighbors) between normal portal area, bile duct hyperplasia and periductal fibrosis. Therefore, a combination of MPM and image-based quantitative analysis may be considered as a rapid and effective means to monitor histopathological changes in portal area and offer new insights into liver fibrosis.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"5 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrically-driven IMT and volatile memristor behavior in NdNiO3 films","authors":"O D Schneble, I A Leahy, J D Zimmerman, M B Tellekamp","doi":"10.1088/1361-6463/ad714e","DOIUrl":"https://doi.org/10.1088/1361-6463/ad714e","url":null,"abstract":"Transition metal oxides with insulator-metal transitions (IMTs) are uniquely suited for volatile memristor devices that mimic the spiking of biological neurons. Unlike most non-volatile memristors, which often operate via ion migration into filaments, volatile devices utilize a reversible phase change that returns to a ground state in the absence of applied stimulus. In these devices, Joule heating triggers the IMT and changes the bulk resistivity rather than influencing conduction through defects, as in previous studies. This volatile resistive switching behavior has previous been leveraged in niobium and vanadium oxides, but not in rare-earth nickelates, despite their tunable transition temperatures. This study demonstrates an electrically driven IMT in the prototypical rare-earth nickelate, NdNiO₃, in large area devices. While previous work examining the electrically-driven IMT in NdNiO₃ suggests defect-dominated conduction, this study shows clear s-type negative differential resistance (NDR) consistent with temperature-dependent resistivity measurements. The NDR peak-to-valley voltage scales linearly with temperature as expected for conductivity pathways dominated by bulk IMT behavior. Unlike other transition metal oxides, which are modeled using the insulator-metal phase fraction as the internal state variable, a thermoelectric model with temperature as the internal state variable is found to more accurately describe the current–voltage characteristic of NdNiO₃ volatile memristors. Overall, we report the synthesis, fabrication, and characterization of NdNiO₃ volatile memristors with resistivity dominated by bulk-like IMT behavior which is scalable and not dependent upon oxygen vacancy migration or defect mediated conduction pathways.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"7 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In-situ and ex-situ characterizations of PVT-grown 4H-SiC single crystals","authors":"Qinqin Shao, Ruohan Shen, He Tian, Xiaodong Pi, Deren Yang, Rong Wang","doi":"10.1088/1361-6463/ad7149","DOIUrl":"https://doi.org/10.1088/1361-6463/ad7149","url":null,"abstract":"4H silicon carbide (4H-SiC) is one of the most promising candidates in high-power and high-frequency devices, owing to its excellent properties such as wide bandgap, high electron mobility, high electric breakdown field and high thermal conductivity. The physical-vapor-transport (PVT) approach has been broadly adopted to grow 4H-SiC single-crystal boules. Because of the high-temperature growth of 4H-SiC single-crystal boules, the PVT system is a ‘black-box’ system, which decreases the yield and thus increases the cost of 4H-SiC single-crystals. Although advanced modern characterization tools, e.g. atomic force microscopy, <italic toggle=\"yes\">x</italic>-ray topography, x-ray diffraction and Raman scattering spectroscopy, can provide deep insight into the structural and defect properties of 4H-SiC boules, it is rather limited to gain <italic toggle=\"yes\">in-situ</italic> information of the growth process by these <italic toggle=\"yes\">ex-situ</italic> methods. Therefore, the <italic toggle=\"yes\">in-situ</italic> visualization on the evolution of structural morphologies and defects conducted by <italic toggle=\"yes\">x</italic>-ray computed tomography (<italic toggle=\"yes\">x</italic>CT) is of great importance for further development. In this topical review, the application of the <italic toggle=\"yes\">x</italic>CT technology on the <italic toggle=\"yes\">in-situ</italic> visualization of the evolution of the growth front, growth rate, defects, and the mass transport of the source material of 4H-SiC are reviewed. The <italic toggle=\"yes\">ex-situ</italic> characterization of 4H-SiC single-crystal boules are also briefly introduced. This topical review provides insight into the growth process, structural morphology, and defect evolution of PVT-grown 4H-SiC single-crystal boules.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"29 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single-crystal silicon ablation with temporally delayed femtosecond laser double-pulse trains","authors":"Zhengjie Fan, Liangtian Yi, Jing Lv, Wenjun Wang, Guoji Li, Jianlei Cui","doi":"10.1088/1361-6463/ad7300","DOIUrl":"https://doi.org/10.1088/1361-6463/ad7300","url":null,"abstract":"A double-pulse femtosecond laser is used to process single-crystal silicon. Modulating the delay time was discovered to increase the ablation depth and improve the morphology of the ablated surface. The hole fabricated by a dual-pulse with a 200 ps interval is 24.4% deeper than that created by a single pulse of the same energy. Moreover, utilizing a dual pulse with an interval ranging from 100 to 1000 ps produces a considerably smoother ablation area as compared to the single pulse. The effect of the sub-pulse energy ratio of the double-pulse femtosecond laser on the size and morphology of the ablated area was also investigated. As the sub-pulse energy ratio decreases from 3:1 to 1:3, the size of the ablation area initially decreases and then increases, while the size of the ablation area is minimized when the sub-pulse ratio is 1:1, enabling precise control over the machining size. As the energy of the second sub-pulse increases, the ablation area becomes smoother due to the plasma heating of the double-pulse femtosecond laser.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"9 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-current gliding DC discharge in high-speed flows","authors":"K N Kornev, A A Logunov, S A Dvinin","doi":"10.1088/1361-6463/ad726e","DOIUrl":"https://doi.org/10.1088/1361-6463/ad726e","url":null,"abstract":"A low-current gliding discharge (current range 1–5 A) in high-speed air flows of 100–250 m s⁻¹ was experimentally studied. A high-voltage direct current source with a maximum voltage of 4.5 kV was used to create the discharge. The average electron concentration <italic toggle=\"yes\">n</italic>_e ∼ 10¹⁴ cm⁻³ and the plasma ionization degree were determined by measuring the Stark broadening of the hydrogen H<italic toggle=\"yes\">_β</italic> line (<italic toggle=\"yes\">λ</italic>_{H<italic toggle=\"yes\">β</italic>} = 486.1 nm). The estimates of the electric field (<italic toggle=\"yes\">E</italic> ∼ 100 V cm ⁻¹ ÷ 600 V cm⁻¹) in the discharge positive column were found using time-synchronized high-speed video recordings and oscillograms. The gas rotational temperature <italic toggle=\"yes\">T</italic>_g = 7000–9500 K and the vibrational temperature <italic toggle=\"yes\">T</italic>_v = 7000–11 000 K were estimated using optical emission spectroscopy. Time-resolved spectroscopy is used to investigate the effective plasma channel spatial regions from which the N, NH, N₂⁺, O and OH molecules radiate. The difference of the obtained radii indicates the presence of a radial temperature gradient and inhomogeneous plasma composition in the discharge cross section. The possibility of using of gliding discharge to ignite hydrocarbon-air mixtures in the ramjet engines combustors has been experimentally demonstrated.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"5 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Importance of gas heating in capacitively coupled radiofrequency plasma-assisted synthesis of carbon nanomaterials","authors":"Tanvi Nikhar, Sankhadeep Basu, Shota Abe, Shurik Yatom, Yevgeny Raitses, Rebecca Anthony, Sergey V Baryshev","doi":"10.1088/1361-6463/ad6d78","DOIUrl":"https://doi.org/10.1088/1361-6463/ad6d78","url":null,"abstract":"In pursuit of diamond nanoparticles, a capacitively-coupled radio frequency flow-through plasma reactor was operated with methane-argon gas mixtures. Signatures of the final product obtained microscopically and spectroscopically indicated that the product was an amorphous form of graphite. This result was consistent irrespective of combinations of the macroscopic reactor settings. To explain the observed synthesis output, measurements of C₂ and gas properties were carried out by laser-induced fluorescence and optical emission spectroscopy. Strikingly, the results indicated a strong gas temperature gradient of 100 K per mm from the center of the reactor to the wall. Based on additional plasma imaging, a model of hot constricted region (filamentation region) was then formulated. It illustrated that, while the hot constricted region was present, the bulk of the gas was not hot enough to facilitate diamond <italic toggle=\"yes\">sp</italic>³ formation: characterized by much lower reaction rates, when compared to <italic toggle=\"yes\">sp</italic>², <italic toggle=\"yes\">sp</italic>³ formation kinetics are expected to become exponentially slow. This result was further confirmed by experiments under identical conditions but with a H₂/CH₄ mixture, where no output material was detected: if graphitic <italic toggle=\"yes\">sp</italic>² formation was expected as the main output material from the methane feedstock, atomic hydrogen would then be expected to etch it away <italic toggle=\"yes\">in situ</italic>, such that the net production of that <italic toggle=\"yes\">sp</italic>²-hybridized solid material is nearly a zero. Finally, the crucial importance of gas heating was corroborated by replacing RF with microwave source whereby facile <italic toggle=\"yes\">sp</italic>³ production was attained with H₂/CH₄ gas mixture.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"7 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discharge fault type identification of C4F7N/CO2/O2 mixed insulating gas for engineering based on product components","authors":"Guangkai Cui, Cong Wang, Yuan Yang, Hao Wang, Youping Tu, Zhong Zheng, Hua Jin","doi":"10.1088/1361-6463/ad714c","DOIUrl":"https://doi.org/10.1088/1361-6463/ad714c","url":null,"abstract":"Perfluoroisobutyronitrile (C₄F₇N) gas mixture is considered one of the most promising alternative gases for SF₆ due to its excellent environmental protection and insulation performance. At present, the Shanghai region of China has adopted 8.5% C₄F₇N-86% CO₂-5.5% O₂ proportion gas mixture as the insulation medium for 126 kV gas insulated switchgear and has put it into practical engineering application. This paper conducted decomposition experiments on the proportion gas mixture under spark discharge, suspension discharge, and corona discharge conditions, respectively. The composition analysis of the decomposition products was carried out using a gas chromatography mass spectrometry and a gas chromatography-pulsed discharge helium ionization detector, which got decomposition products of the C₄F₇N/CO₂/O₂ gas mixture under discharge faults mainly include CO, CF₄, C₃F₈, C₄F₈, C₃F₆, and CF₃CN. According to the decomposition path of the C₄F₇N gas mixture, this paper selected three primary decomposition products (CO, CF₄, C₃F₈) and one secondary decomposition product (C₄F₈) for the correlation characterization of discharge types, and proposed the ratios of c(CO)/c(CF₄) and c(C₄F₈)/c(C₃F₈) as the characteristic quantities to characterize the different discharge types. Finally, in order to accurately identify the C₄F₇N/CO₂/O₂ gas mixture discharge type, this paper chose the decision tree algorithm to build a identification tree. The final identification result indicates that the ratio of c (CO)/c (CF₄) and c (C₄F₈)/c (C₃F₈) can be used as the identification criterion for typical discharge fault types.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"34 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oxidative aggregation of hemoglobin–a mechanism for low-temperature plasma-mediated wound healing","authors":"Irina Oganesyan, Alina Begley, Dušan Mrđenović, Julian A Harrison, Renato Zenobi","doi":"10.1088/1361-6463/ad6e99","DOIUrl":"https://doi.org/10.1088/1361-6463/ad6e99","url":null,"abstract":"Plasma medicine is a field that utilizes reactive species generated from atmospheric low-temperature plasmas for applications such as sterilization, blood coagulation, and cancer therapy. Commercial plasma devices are available for wound healing, but research on the chemical modifications induced by these plasmas is scarce. This study explores the chemical modifications in hemoglobin when exposed to a helium plasma dielectric barrier discharge, with the aim of explaining the potential mechanisms through which it contributes to blood coagulation and enhances wound healing. Optical microscopy of cold atmospheric plasma (CAP) treated whole capillary blood showed an increase in red blood cell (RBC) size and the formation of rouleaux structures. The treatment of whole blood leads to hemolysis of RBCs and the release of intracellular protein content. We then treated purified hemoglobin protein at physiological concentrations, which led to the formation of aggregates that could be observed using ion mobility mass spectrometry (IM–MS), size exclusion chromatography, and optical microscopy. The aggregates formed fibril-like structures as observed using atomic force microscopy. The formation of hemoglobin aggregates is hypothesized to be the result of new intermolecular interactions formed following the CAP-mediated protein oxidation. We studied the changes to hemoglobin structure after treatment with a CAP using high-resolution MS and found that the hemoglobin subunits are oxidized with the addition of at least 4 oxygen atoms each. The intact tetrameric hemoglobin structure remains unchanged; however, the monomeric and dimeric proteins adopt a more compact structure, as observed by IM–MS. We propose that CAP treatment of fresh blood leads to hemolysis, and that the extracellular protein, primarily hemoglobin, is oxidized leading to the formation of aggregates.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"20 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}