共查询到20条相似文献,搜索用时 388 毫秒
1.
2.
3.
本文对反平行磁电垒结构中二维电子气体的输运性质进行了详细的研究.利用传递矩阵的方法计算了电子气体隧穿磁电垒结构的传输概率和电导率,讨论了电势垒高度的变化对传输概率和电导率的影响.结果表明,该系统中不存在自旋过滤和自旋极化现象,电子气体可实现理想的共振隧穿,波矢过滤等. 相似文献
4.
提出了一种精确求解隧穿电流的模型。通过自洽求解一维薛定谔方程和泊松方程,得到NMOS器件的半导体表面电势分布、反型层二维电子气的量子化能级以及对应的载流子浓度分布。为计算隧穿电流,采用了多步势垒逼近方法计算栅氧化物势垒层的隧穿几率,从而避免了WKB方法在突变边界处波函数不连续带来的缺陷。通过考虑(100)Si衬底的导带多能谷效应和栅极多晶硅耗尽效应,讨论了不同栅氧化层厚度下隧穿电流与栅压的依赖关系。模拟结果与实验数据吻合。 相似文献
5.
多重散射理论对光子晶体量子阱结构光子共振透射的研究 总被引:4,自引:1,他引:3
用球面波展开的多重散射理论计算了光子量子阱的透射系数.光子量子阱由两层光子势垒之间夹置一层均匀介质构成,由于光子带隙的失配,类似于电子量子阱,形成所谓光子量子阱.对透射峰位置的计算结果表明某些光子态以量子化的形式存在,满足量子化频率关系.同时证明有限高的光子势垒在不同光子能级中起到不同的限制作用.共振峰的位置和数量可通过改变阱宽而实现人工调控,通过适当选择阱和垒的参数能够实现高质量的多通道滤波.对光子晶体耦合双量子阱的计算表明,当阱间的垒宽度增加时,两个模式的耦合减弱,模式分裂的间距减小. 相似文献
6.
The author analyzes resonant electron tunneling in parallel-plane heterostructures that have a central well region enclosed by two generalized barriers, which are reflectors of the Bloch waves. A single Bloch pair is assumed for the central region as well as in the surrounding semi-infinite semiconductors. The transmission probability versus electron energy is obtained for this model in terms of the transmission probabilities of the two barrier elements taken separately and the quasi-classical transit time for the trapped electron to make one circuit of the central well layer. The implications and limitations of these results are briefly discussed 相似文献
7.
8.
A simple method for the analysis of tunneling through an arbitrary one-dimensional potential barrier, based on the modified Airy function approach, is presented. Truncated step-linear, step-exponential, parabolic, and quartic potential barriers are considered. The results are compared with those obtained by the conventional WKBJ, modified WKBJ, and matrix methods. The effect of the truncation level on the tunneling coefficient is investigated. The tunneling coefficient is sensitive to the truncation level. For the step-linear potential, the tunneling coefficient is a monotonically decreasing function of the truncation level, while for the parabolic potential, it oscillates before saturating to a constant value 相似文献
9.
利用传递矩阵的方法研究了含有一个方势垒的单层石墨烯的隧穿特性,得到了透射概率与入射粒子费米能以及势垒宽度、势垒高度的变化关系,并且计算了势垒的结构参数及入射粒子费米能对低温电导的影响.这些结果可以为设计基于石墨烯材料的纳米器件提供理论参考. 相似文献
10.
The method of images is used to calculate the electrostatic potential of an electric charge inside a double barrier structure. This potential is important for finding impurity energy levels in the quantum structure and has never been used before in exact form. The media were modeled by assigning different dielectric constants to the barriers and to the well. The highly doped contacts were assumed to have infinite dielectric constants. This method is based on calculating the Fourier transform parallel to the interfaces of the potential. This function can be obtained in closed form. The potential is then obtained by inverse Fourier transform. This integral is computationally more efficient to evaluate than the direct sum of Coulomb image terms 相似文献
11.
Presents a simple general and exact method for solving resonant tunneling problems in multilayered heterostructures. This method is based on the analogy of wave propagation between the transmission line and the potential structure. By using the proposed method, it is shown that electron wave propagation can be treated as wave propagation on an equivalent circuit and that various problems can be systematically solved by using well-developed circuit functions and circuit matrixes. In particular, our equivalent circuit can be effectively used for analysis of resonant interband tunneling (RIT) structures and resonant tunneling structures including Γ-X mixing by using the interface matrix. Various properties of the resonant tunneling structure and a guideline for designing new quantum effect devices can be easily obtained. In order to show the validity and usefulness of this method, some numerical examples of InAs-GaSb and GaAs-AlAs potential barrier structures are presented 相似文献
12.
Using the transfer matrix method, we theoretically investigate the electron transport properties in a three-barrier structure based on monolayer graphene. The numerical results show that the transmission probability and the conductance strongly depend on the barrier height, the barrier width and the incident energy as well as the incident angle of carriers. Therefore, by changing the configuration of the structure, the electron transport properties can be adjusted to be suitable for the practical application in various graphene-based electronic devices such as the graphene-based transistor with the high on/off ratio and the direction-dependent wave vector filter. 相似文献
13.
N. V. Vishnyakov S. P. Vikhrov V. G. Mishustin A. P. Avachev I. G. Utochkin A. A. Popov 《Semiconductors》2005,39(10):1147-1152
The formation of potential barriers in undoped disordered semiconductors is considered. A generalized model of the potential barrier formation in such structures is examined using the example of a metal-amorphous hydrogenated silicon contact. It is shown that the properties of barriers in disordered semiconductors are determined by the energy distribution of the localized states in the mobility gap. An analytical expression for the electric field and potential in the space-charge region of a disordered semiconductor is obtained and a new method for the formation of surface quasi-ohmic contacts is suggested. 相似文献
14.
采用简化的对称势垒连续隧穿模型模拟复合分子线电子器件低偏压下电子隧穿过程,并由电子透射谱随垒宽、垒距、垒高及电子有效质量的变化规律推断低偏压下分子器件的电导规律.结果发现:随着势垒增宽或增高,分子器件的低偏压电导G明显变小;但是随着垒距或电子有效质量增大,则分子器件的低偏压电导G反而变大.这表明可以通过适当的控制方式(如改变复合分子组成、构型等)来修改分子电子器件的低偏压输运性质. 相似文献
15.
16.
薛舫时 《固体电子学研究与进展》1992,12(4):326-331
本文从单带双谷模型出发研究了电子在量子阱内遭到散射时电子状态及隧穿几率的变化。弹性散射使用δ散射势来计算,非弹性散射则用虚散射势来描述。前者使隧穿电流峰向高电压端移动,后者减弱了电流峰的谐振强度。分别讨论了位于势阱和势垒层中的散射中心的不同散射作用。隧穿电流的变化趋势同中子辐照实验数据相吻合。 相似文献
17.
Jen-Inn Chyi Shin-Kai Wang Jing-Horng Gau Jia-Lin Shieh Jen-Wei Pan 《Quantum Electronics, IEEE Journal of》1996,32(3):442-447
The enhancement of electron barrier height by multistack multiquantum barrier structure is simulated using the transfer matrix method. The validity and feasibility of this concept is verified by the experimental results on GaAs-AlAs multistack multiquantum barriers. Based on the simulated results, both 0.78 and 1.3 μm graded-index separate confinement heterostructure (GRIN-SCH) lasers with predicted enhanced carrier and optical confinements using graded multistack multiquantum barriers are designed. Lower threshold current, higher modulation bandwidth as well as higher characteristic temperature are expected for these lasers 相似文献
18.
D. A. Komarov S. P. Morev A. N. Darmaev A. Yu. Ryadnov 《Journal of Communications Technology and Electronics》2014,59(8):843-846
A numerical model is proposed for the solution of the Schröbinger equation. The model is based on the scattering matrix of the solution region. The scattering matrix is formed from matrices of partial regions of a simple shape. The density of the self-emission current for a metal/vacuum potential barrier of an arbitrary form is calculated. The results of test calculation of electron transmission through a rectangular potential barrier with a relative error less than 0.001% as compared to the analytical solution are presented. 相似文献
19.
F. I. Zubov M. V. Maximov N. Yu. Gordeev Yu. S. Polubavkina A. E. Zhukov 《Semiconductors》2018,52(2):248-253
A semiconductor-laser design is proposed in which parasitic recombination in the waveguide region is suppressed by means of double asymmetric barriers adjacent to the active region. Double asymmetric barriers block the undesirable transport of one type of charge carrier while allowing the transport of the other type of carrier. The spacer in the double asymmetric barrier can serve to compensate the elastic strain introduced by the barrier layers as well as to control the energy spectrum of charge carriers and, thus, the transmission coefficient. By the example of a laser with Al0.2Ga0.8As waveguide layers, it is shown that the design with double asymmetric barriers makes it possible to suppress undesirable electron transport by a factor of 4 in comparison to the design using single asymmetric barriers. 相似文献
20.
Schottky barriers on n-GaN grown on SiC 总被引:2,自引:0,他引:2
E. V. Kalinina N. I. Kuznetsov V. A. Dmitriev K. G. Irvine C. H. Carter 《Journal of Electronic Materials》1996,25(5):831-834
Characteristics of Schottky barriers fabricated on n-type GaN were investigated. The barriers were formed by vacuum thermal
evaporation of Cr, Au, and Ni. Current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the barriers were measured
in a wide temperature and current density range. Fundamental parameters (barrier height and built-in potential) of the Schottky
barriers were determined. The dependence of the barrier ideality factor on doping concentration in GaN was measured. Correlation
between the barrier height and metal work function was observed. The electron affinity for GaN was determined using both C-V
and I-V characteristics. The current flow mechanism through the barriers is discussed. 相似文献