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探索二维材料与其衬底之间的黏附性能对于二维材料的制备、转移以及器件性能的优化至关重要.本文基于原子键弛豫理论和连续介质力学方法,系统研究了尺寸和温度对MoS2/SiO2界面黏附性能的影响.结果表明,由于表面效应引起的热膨胀系数、晶格应变和杨氏模量的变化, MoS2/SiO2界面黏附能随MoS2厚度的减小而增大,而热应变使MoS2/SiO2界面黏附能随温度的升高而逐渐降低.此外,预测了在不同尺寸和温度下MoS2在SiO2衬底上的“脱落”条件,系统阐述了MoS2与SiO2衬底之间黏附性能的物理机制,为基于二维材料电子器件的优化设计提供了理论基础. 相似文献
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用气体中蒸发的方法在蓝宝石基片上制备了纳米InSb颗粒膜.通过透射电镜分析显示,该方法可以制得多晶的InSb纳米颗粒,且颗粒均匀地分布在蓝宝石基片表面上;用X射线能谱仪分析样品得到两种元素的百分比接近1:1.实验结果表明,通过改变设备的工作条件,可以得到具有不同颗粒尺寸的InSb纳米颗粒. 相似文献
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采用在惰性气体中蒸发的方法获得了沉积在ZnS基片上的InSb纳米晶体,其平均尺寸随惰性气体的压强增加而增大.从实验测量的室温吸收谱上看到,当纳米晶体的平均直径从27.9 nm减小到24.2nm再到21.4 nm时,其吸收边分别向高能方向移动了0.0151 eV和0.0145 eV.用有效质量近似模型计算了半导体纳米晶体的吸收边相对其体材料的移动,将理论计算与实验结果进行了比较. 相似文献
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采用反应磁控溅射法制备了一系列不同SiO2层厚度的AlN/SiO2纳米多层膜,利用X射线衍射仪、高分辨透射电子显微镜和微力学探针表征了多层膜的微结构和力学性能,研究了SiO2层在多层膜中的晶化现象及其对多层膜生长方式及力学性能的影响. 结果表明,由于受AlN六方晶体结构的模板作用,溅射条件下以非晶态存在的SiO2层在其厚度小于0.6 nm时被强制晶化为与AlN相同的六方结构赝晶体并与AlN形成共格外延生长. 由于不同模量的两调制层存在晶格错配度,多层膜中产生了拉、压交变的应力场,使得多层膜产生硬度升高的超硬效应. SiO2随层厚的进一步增加又转变为以非晶态生长,多层膜的外延生长结构受到破坏,其硬度也随之降低.
关键词:
2纳米多层膜')" href="#">AlN/SiO2纳米多层膜
赝晶化
应力场
超硬效应 相似文献
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为实现表面增强拉曼散射(SERS)信号的快速检测分析,报道了一种简单的利用SiO2包覆对巯基苯甲酸(4MBA)修饰的Ag纳米粒子形成核壳结构纳米颗粒SERS标记物的方法。通过调控溶液中硝酸钠的浓度来控制4MBA-Ag的聚集程度,获得不同的“热点”效应,然后利用SiO2包覆实现对聚集体的固定。扫描电镜结果证实此种方法非常有效。该体系中SERS的信号强度依赖于4MBA-Ag的聚集程度。该研究结果有助于实现聚集体SERS标记物在生物成像、检测和传感等方面的应用。 相似文献
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用射频/直流磁控溅射法制备了CeO2/Nb2O5双层氧敏薄膜,利用X射线光电子能谱(XPS),描述并解释了单层CeO2薄膜中氧随温度变化的动力学行为,以及CeO2/Nb2O5薄膜界面对氧敏特性的影响.通过对Ce3d XPS谱的高斯拟合,计算了Ce3+浓度并给出了判定Ce4+还原的标志.结果表明,界面效应可以提高CeO2/Nb2O5薄膜中Ce4+的还原能力,使之远远高于单层CeO2薄膜,这对薄膜的氧敏特性是极为有利的.
关键词: 相似文献
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本文采用两个互相垂直的Wilhelmy片对不同润湿性的SiO2纳米颗粒单层膜的表面压和黏弹性进行了研究, 并利用Brewster角显微镜(BAM)对单层膜的形貌演变进行了观测. 实验发现, 当水面完全被颗粒覆盖时, 单层膜的表面压具有明显的各向异性, 中等润湿性(34%SiOH)的颗粒膜其表面压各向异性最大. 压缩模量E和剪切模量G均在中等润湿性时出现最大值. 这些结果表明, 单层膜的流变性能与泡沫的稳定性密切相关. 疏水性最强(20%SiOH)的颗粒膜具
关键词:
纳米颗粒
单层膜
表面压
流变 相似文献
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Tong Zhang M. Debnath S. K. Clowes W. R. Branford A. Bennett C. Roberts L. F. Cohen R. A. Stradling 《Physica E: Low-dimensional Systems and Nanostructures》2004,20(3-4):216
Both magneto-resistive sensors and spintronic hybrid semiconductor devices require thin epitaxial layers of high-mobility InSb. Here we study unintentionally doped InSb epilayers grown on semi-insulating GaAs(100) substrates by molecular-beam epitaxy. We have introduced an initial low-temperature growth step extending the work that the NTT group reported in 2000. We find significant improvement in the room temperature mobility for epilayer thickness between 60 and 300 nm. The importance of the initial growth step to the epilayer mobility performance is discussed. 相似文献
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We calculate the warping of the bulk dispersion of InSb in thek-space using different models for the bulk band structure near the Γ point. It is shown that the dispersion of the conduction
band Γ6 is well described by the simplified six-band model, while the fourteen-band model is more accurate for the valence bands. 相似文献
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Mohammad Saleh Gorji 《固体与材料科学评论》2015,40(4):197-222
Schottky and Ohmic contacts are essential parts of electronic and optoelectronic devices based on semiconductor materials. Controlling the contact/semiconductor interface properties is the key to obtaining a contact with an optimum performance. Contacts incorporated by nanomaterials, i.e., nano-sized particles that are embedded at the interface of contact/semiconductor, can transform the conventional approaches of contact fabrication, resulting in more reproducible, tunable and efficient electronic, and optoelectronic devices. This article is a review of theoretical and fabrication progress on the last two decades to produce contacts with embedded nanoparticles (NPs). The review covers common routes of NPs deposition on different substrates (e.g., Si, Ge, SiC, GaN, GaAs67P33, and InP) for nanostructured contact fabrication and the theoretical models to investigate the NPs effects on the conduction mechanism and electrical properties of devices. 相似文献
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The intrinsic carrier concentration in InSb was determined, between 246 and 370 K, by a helicon method consisting of a microwave
interferometer at 34 GHz. The accuracy of the carrier concentration is between 1–2%. The influence of experimental parameters
on the determination of the carrier concentration and the mobilities of both electrons and holes is discussed in detail. Comparing
the data obtained for the carrier concentration with Hall effect measurements a small difference of the absolute values is
found. The band-gap deduced is in agreement with the Hall effect measurements. 相似文献
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功能性硫化镉纳米粒子荧光增敏法测定诺氟沙星 总被引:3,自引:0,他引:3
室温条件下在水溶液中以硫代乙酰胺和硝酸镉为原料,采用微波法合成了粒度分布均匀、分散性好的CdS纳米粒子,在pH 7.4时,CdS纳米粒子的荧光强度能够被诺氟沙星增敏,且CdS纳米粒子的荧光光谱显示其带边发射位于495 nm,缺陷发射位于565 nm而且不明显,所以表明合成的CdS纳米粒子的光学性质较好,同时紫外吸收光谱和透射电子显微镜也证明了此推论。同时考察了缓冲液、pH值、离子强度、反应时间和温度等条件因素对CdS纳米粒子-诺氟沙星复合体系荧光光谱特性的影响。探讨了在最佳实验条件下,CdS纳米粒子与诺氟沙星之间的可能作用机理,荧光光谱法显示CdS纳米粒子的增加强度与诺氟沙星浓度成正比, 其浓度范围为1.25~11.25 μg·mL-1或11.25~100.0 μg·mL-1,检测限为1.5×10-3 μg·mL-1。该方法为研究诺氟沙星含量测定提供了一种新的思路, 同时为研究其在体内代谢提供了一定的指导意义。 相似文献
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Shuichi Ishida Keiki Takeda Atsushi Okamoto Ichiro Shibasaki 《Physica E: Low-dimensional Systems and Nanostructures》2004,20(3-4):255
Magnetoresistance (MR) effects have been investigated in perpendicular and parallel magnetic fields at 300, 80 K and liquid He temperatures for undoped InSb thin films 0.1–2.3 μm thick grown on GaAs(1 0 0) substrates by MBE. At high temperatures, the intrinsic carriers show the parabolic negative MR observable only in magnetic fields parallel to the film. The skipping-orbit effect due to surface boundary scattering in the classical orbits in the plane vertical to the film has been argued to be responsible for the negative MR. At low temperatures (T=80 K), the transport is dominated by the two-dimensional (2D) electrons in the accumulation layers at the InSb/GaAs(1 0 0) hetero interface; MR is positive and shows a logarithmic increase with anisotropy between parallel and perpendicular field orientation, arising from the 2D weak anti-localization (WAL) that reflects the interplay between the spin-Zeeman effect and strong spin–orbit interaction caused by the asymmetric potential at the interface (Rashba term). The zero-field spin splitting energy of Δ013 meV, the electron effective mass of m*0.10m0 seven times of the band edge mass in bulk InSb and the effective g-factor of |g*|15 in the accumulation layer have been inferred from fits of MR for the 0.1 μm thick film to the 2D WL theory. 相似文献
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DONG ZhengChao 《理论物理通讯》2000,33(1):55-62
An analytical Green's function approach to the study of the electronic transport in a magnetic sandwich structure is presented. Taking into account the quantum size effect and considering three types of scattering from bulk impurities, rough surface, and two rough interfaces, we calculate the one-particle Green's function and the in-plane conductivity, yield a new formula for conductivity. It is found that (i). the magnetoresistance in the ultrathin spin-value sandwiches shows oscillation as a function of thickness with a period of half Fermi wavelength; (ii) in the thin-film limit and the lowest-order approximation of the surface and interface scatterings, the total conductivity is given by a sum of conductivities of all the subbands and the two spin channels, for each subband and each spin channel the scattering rates due to the impurities, surfaces and interfaces are additive. 相似文献