通过一种单步水热法成功制备了花状VS_2纳米片。利用X射线衍射仪(XRD)、拉曼光谱、场发射扫描电镜(SEM)和透射电子显微镜(TEM)等手段对样品进行表征,并研究了其生长机制。实验结果表明:反应温度及时间的不同直接影响着VS_2纳米片的形貌...通过一种单步水热法成功制备了花状VS_2纳米片。利用X射线衍射仪(XRD)、拉曼光谱、场发射扫描电镜(SEM)和透射电子显微镜(TEM)等手段对样品进行表征,并研究了其生长机制。实验结果表明:反应温度及时间的不同直接影响着VS_2纳米片的形貌。此外,通过使用VS_2纳米片作为锂离子电池阳极材料,分别研究了充放电电压和循环性能等性质。在200 m A/g电流密度下,电池初始充放电能力分别为195.4和90.6 m Ah/g。随着循环充放电的进行,该电极材料的库伦效率高达98%。可以认为VS_2纳米材料具备高效、高能量密度锂离子电池的阳极材料。展开更多
Electron beam lithography(EBL) is a key technology in the fabrication of nanoscale silicon optical waveguide. The influence of exposure dose, the main process parameter of EBL, on the structure profile of poly-methyl ...Electron beam lithography(EBL) is a key technology in the fabrication of nanoscale silicon optical waveguide. The influence of exposure dose, the main process parameter of EBL, on the structure profile of poly-methyl methacrylate(PMMA) after development was studied using a silicon on insulator(SOI) wafer with 220 nm top silicon as the substrate. The relationship between exposure dose and structure pattern width after development was analyzed according to the measurement results. The optimum exposure dose of 220 μC/cm^(2) was found to obtain a final structure consistent with the designed mask value through subsequent processes. At the same time, according to the image segmentation curve tracking technology, the contour extraction process of the dose test results was carried out, and the relationship among mask design value, exposure dose and two-dimensional roughness of boundary contour was analyzed, which can provide reference for the subsequent electron beam lithography of the same substrate material.展开更多
Using the first-principles band-structure method and a special quasirandom structure(SQS) approach,we have systematically calculated the alloy bowing coefficients and the nature band offsets of SnxZn1-x Te alloys.We s...Using the first-principles band-structure method and a special quasirandom structure(SQS) approach,we have systematically calculated the alloy bowing coefficients and the nature band offsets of SnxZn1-x Te alloys.We show that the bowing coefficients and band gaps of these alloys are sensitively composition dependent.Due to wave functions full overlapping and delocalization of the Sn outermost p orbits and Zn s orbits,the coupling between these states is very strong,resulting in a significant downshift of conduction band edge with the increase of the Sn concentration x,While the valence band edge keeps almost unchanged compared with that of the binary ZnTe,thus improving the possibility for ambipolar-doping.展开更多
基金Hunan Provincial Innovation Foundation for Postgraduate(CX2014B127)
文摘通过一种单步水热法成功制备了花状VS_2纳米片。利用X射线衍射仪(XRD)、拉曼光谱、场发射扫描电镜(SEM)和透射电子显微镜(TEM)等手段对样品进行表征,并研究了其生长机制。实验结果表明:反应温度及时间的不同直接影响着VS_2纳米片的形貌。此外,通过使用VS_2纳米片作为锂离子电池阳极材料,分别研究了充放电电压和循环性能等性质。在200 m A/g电流密度下,电池初始充放电能力分别为195.4和90.6 m Ah/g。随着循环充放电的进行,该电极材料的库伦效率高达98%。可以认为VS_2纳米材料具备高效、高能量密度锂离子电池的阳极材料。
基金Project(52175445) supported by the National Natural Science Foundation of ChinaProject(ZZYJKT2020-09) supported by the State Key Laboratory of High Performance Complex Manufacturing (Central South University),China+1 种基金Projects(2020JJ4247, 2022JJ30743) supported by the Natural Foundation of Hunan Province,ChinaProject(1053320190337) supported by the Fundamental Research Funds for the Central University,China。
文摘Electron beam lithography(EBL) is a key technology in the fabrication of nanoscale silicon optical waveguide. The influence of exposure dose, the main process parameter of EBL, on the structure profile of poly-methyl methacrylate(PMMA) after development was studied using a silicon on insulator(SOI) wafer with 220 nm top silicon as the substrate. The relationship between exposure dose and structure pattern width after development was analyzed according to the measurement results. The optimum exposure dose of 220 μC/cm^(2) was found to obtain a final structure consistent with the designed mask value through subsequent processes. At the same time, according to the image segmentation curve tracking technology, the contour extraction process of the dose test results was carried out, and the relationship among mask design value, exposure dose and two-dimensional roughness of boundary contour was analyzed, which can provide reference for the subsequent electron beam lithography of the same substrate material.
基金Supported by the National Basic Research Program of China under Grant No. 2011CB606405the Hunan Provincial Natural Science Foundation of China under Grant No. 11JJ4002the Fundamental Research Funds for the Central Universities
文摘Using the first-principles band-structure method and a special quasirandom structure(SQS) approach,we have systematically calculated the alloy bowing coefficients and the nature band offsets of SnxZn1-x Te alloys.We show that the bowing coefficients and band gaps of these alloys are sensitively composition dependent.Due to wave functions full overlapping and delocalization of the Sn outermost p orbits and Zn s orbits,the coupling between these states is very strong,resulting in a significant downshift of conduction band edge with the increase of the Sn concentration x,While the valence band edge keeps almost unchanged compared with that of the binary ZnTe,thus improving the possibility for ambipolar-doping.
