共查询到19条相似文献,搜索用时 62 毫秒
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纳米线、纳米管的制备、表征及其应用 总被引:10,自引:0,他引:10
在高度集成化浪潮的推动下,现代技术对纳米尺度功能器件的需求将越来越迫切。纳米线、纳米管等一维材料作为纳米器件中必不可少的功能组件,在纳米研究领域中的地位显得愈发重要。本文从一维纳米材料的研究范畴入手,介绍了纳米线、纳米管的制备方法,技术要点以及各种相关表征方法,并涉及了当前一维纳米材料的一些应用研究,为基于纳米线、纳米管功能器件的研制提供前期参考。 相似文献
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铁电纳米材料和纳米结构(如纳米线、纳米管、纳米环)具有新型尺寸效应特性,在铁电基电子器件的微型化方面受到广泛关注.近年来在铁电纳米材料和纳米结构的制备和(电性能和微结构)表征及理论模拟方面取得了相当进展,本文对这方面的最新进展进行评述.首先对高质量的铁电纳米材料和纳米结构的制备方法进行了简短评述,然后介绍铁电纳米材料和纳米结构的纳尺度物性表征.随后介绍了最近发展的四种理论模型(尤其对铁电纳米管、纳米线、纳米点),以及从第一原理出发理论模拟铁电纳米结构的新现象,如铁电纳米结构的自发极化螺旋有序和自发极化涡旋结构.最后总结了铁电纳米材料和纳米结构的微结构研究进展,并讨论了有关铁电纳米结构中自发极化螺旋畴的一些基础物理问题以及实验上寻找自发极化螺旋畴的研究进展. 相似文献
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从硅纳米管和纳米线场效应晶体管的结构出发,先用Silvaco公司的TCAD仿真软件模拟出硅纳米管和纳米线的电势分布,然后根据电势分布依次求出两种器件的有效哈密顿量、非平衡格林函数及自能函数和电子浓度,再从电子浓度推导出电流密度与电压方程,并对其进行了分析比较。仿真结果显示,在沟道横截面积相同的情况下,纳米管器件的阈值电压比纳米线器件的高,且随管内外径之差的增加而减小。栅压比较大的情况下,在饱和区纳米管器件比纳米线器件能提供更大的驱动电流。两者在亚阈值区域表现相似,亚阈值摆幅分别为58和57 mV/dec。纳米管器件的饱和电压比纳米线器件的略小,在饱和区纳米管器件的电流更加平直,短沟道效应更不明显。 相似文献
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《中国激光》2020,(2)
肿瘤是现代医学亟须克服的难题,肿瘤的早筛查、早治疗始终是临床医学的重大需求。本文评述了基于纳米粒子、纳米线、纳米管和纳米阵列来检测肿瘤标志物的纳米生物传感器的基本原理和检测特性。壳核纳米粒子具有丰富的修饰功能;纳米线多被制成场效应管以检测肿瘤标志物;基于良好的尺度效应,纳米管多用于载体运输及平台检测;金属纳米阵列和金属氧化物纳米阵列可利用电化学阻抗谱的原理来检测癌细胞。除由不同形态结构决定的优势和应用特点以外,与传统的检测方法相比,光学纳米生物传感器检测癌细胞具有快速便捷、检出质量浓度低等优势,因而在医学检测和肿瘤研究中得到了一定的应用,具有较大的发展潜力。 相似文献
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采用以Zn粉、C粉为原料,采用热蒸发法,在没有任何载气和700℃下制备了四脚针状ZnO纳米结构。C粉起到了催化剂的作用但产物却不存在催化剂去除的问题,同时C粉氧化生成的CO/CO2还起到了载气的作用。扫描电镜(SEM)表明,四脚针状ZnO具有很细的尖端,直径为50 nm。X射线衍射(XRD)、微区拉曼图谱的特征峰表明,四脚针状ZnO是高纯的六角纤锌矿结构。光致发光(PL)谱在403 nm附近有微弱的紫光发射峰,而在510 nm附近出现了很强的绿光发射峰。 相似文献
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We suggest a scenario for the formation of quantum dots during Ostwald ripening of three-dimensional islands grown heteroepitaxially in the Stranski-Krastanow mode. We demonstrate that the size-distribution function narrows down and the variance decreases noticeably if the growth proceeds through dislocation diffusion followed by the detachment of dislocations from island bases. Plausible reasons for termination of the Ostwald ripening of the islands are discussed. 相似文献
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On the basis of analytical and numerical solutions of the Schrödinger equation, the active polarization current and emission efficiency of double-well nanostructures were calculated in a wide range of amplitudes of alternating electromagnetic field. It is shown that generation in the important terahertz region with smooth frequency tuning and the highest efficiency are possible. The behavior of the coefficient of reflection of electrons from the structure is studied; this coefficient goes to zero under the conditions of maximum efficiency. 相似文献
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Si基纳米结构的电子性质 总被引:1,自引:0,他引:1
各种Si基纳米发光材料在Si基光电子器件及其全Si光电子集成技术中具有潜在的应用前景,从理论和实验上对其电子结构进行研究,有助于我们深化对其发光机制的认识与理解。本文主要从量子限制效应发光这一角度,着重介绍了Si纳米晶粒、Ge/Si量子点,SiO2/Si超晶格和超小尺寸Si纳米团簇等不同Si基纳米结构的电子性质以及它们与发光特性之间的关系。还讨论了介质镶嵌和表面钝化对其电子结构的影响。 相似文献
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N. T. Bagraev L. E. Klyachkin A. A. Koudryavtsev A. M. Malyarenko V. V. Romanov 《Semiconductors》2009,43(11):1441-1454
Superconducting properties of silicon sandwich nanostructures on the n-Si (100) surface, which represent the ultra-narrow p-type silicon quantum wells confined by heavily boron-doped δ barriers, manifest themselves in the measurements of the temperature and field dependences of resistivity, thermopower, heat capacity, and static magnetic susceptibility. The cyclotron-resonance, scanning-tunneling-microscopy, and ESR data identify the presence of the single trigonal negative-U dipole boron centers in nanostructured δ barriers B +-,B ?, which are formed due to the reconstruction of shallow boron acceptors, 2B 0 ? B + + B ?. The obtained results indicate that these negative-U centers are responsible for the transport of small-radius hole bipolarons, which is likely the basis of the mechanism of high-temperature superconductivity with T C = 145 K. The superconductor-gap value of 0.044 eV determined from the measurements of the critical temperature using the above techniques is almost identical to the data on the tunneling spectroscopy and direct record of tunneling I–V characteristics. The quantization of the superconductive characteristics for silicon sandwich nanostructures manifests itself in the temperature and field dependences of the heat capacity and static magnetic susceptibility, which show the oscillations of the second critical field and critical temperature arising due to the supercurrent quantization. 相似文献
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Tignon J. Marquezini M.V. Hasche T. Chemla D.S. 《Quantum Electronics, IEEE Journal of》1999,35(4):510-522
Fourier transform spectral interferometry is applied to measure both amplitude and phase of the electric field in different types of semiconductor nanostructures, thus determining the real and imaginary parts of the dielectric function. The importance of measuring the phase is shown and discussed in three studies. First, the phase measurement is used to access directly the refractive index across excitonic resonances in bulk GaAs and AlGaAs-GaAs quantum wells, with unprecedented resolution. Second, we measure the density dependence of the full dielectric function across a Fano resonance in bulk GaAs and show that this allows us to obtain some information on the collisional broadening of the usually hidden linewidth of the coupled exciton/continuum. Third, the phase is studied in a complex heterostructure, a semiconductor microcavity. We investigate and discuss the effect of the cavity detuning and of the excitation density 相似文献
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A model of impedance δ-inhomegeneities for wave micro- and nanostructures of different nature has been proposed. This model combines the advantages of approaches based on δ-function and wave impedance. Analytic expressions were derived for single- and two-phase resonators and crystal-like structures. The characteristics of resonators based on finite width inhomogeneities and δ-inhomogeneities, and also the characteristics of single- and two-phase resonators were compared. 相似文献