共查询到17条相似文献,搜索用时 78 毫秒
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在16K至室温范围内测量了ZnSe-ZnS应变层超晶格的激子吸收谱.观测到对应于1E-1HH1E-1LH及1E-3HH跃迁的三个激子吸收峰. 相似文献
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本文首次利用室温非共振喇曼后向散射测得具有7.3%晶格失配的ZnSe-ZnTe应变层超晶格限制在ZnSe层中的纵光学声子模。计算了限制效应引起的声子模频率的红移,以及弹性应变引起的声子模的移动,它比前者大得多。ZnSe层所受拉伸应变引起声子频率红移,ZnTe层所受压缩应变引起声子频率蓝移。同时在喇曼光谱中观察到由于这种效应导致出现的纵光学声子折叠模。 相似文献
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关于ZnSe—ZnS应变超晶格P型导电机理的探讨 总被引:1,自引:0,他引:1
本文利用变温Hall测量,证实了我们用MOCVD法生长的No.87—39A ZnSe-ZnS应变超品格(SLS)具有P型导电特性。文中试图从应变超晶格的临界厚度,电学参数、能带结构等方面解释ZnSe-ZnS SLS反型的原因。文中指出,这时的受主能级可能处于ZnS层靠近界面附近,这些受主能级的位置比ZnSc阱中满带顶能量低。 相似文献
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考虑到真实超晶格系统的有限宽度会造成晶格的非周期性 ,我们修正了用来决定拉曼频移峰值位置的公式中的倒格矢一项。在线性驰豫应变假设下给出了应变超晶格纵向原子间距的几何模型。在上述理论基础上计算了有限宽度的ZnSe/ZnTe应变超晶格LA声子的拉曼频移。数值计算结果同现有实验结果作了比较 ,符合很好。 相似文献
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In this paper, by the transparent-component-decimation (TCD) method we obtain three kinds of new basic- components (BCs) through simplifying and decomposing the BCs of three-component Thue-Morse (3CTM) sequence. Based on these new BCs we propose a type of basic-structural-units (BSUs) and investigate the optical transmission of the one-dimensional (1D) superlattices composed of these BSUs. It is found that if the substrates of the 1D BSU superlattices are certain, the optical transmission at the central wavelength (CW) will be determined completely by the number and the type of BSUs and has nothing to do with the marshalling sequence. In particular, if the substrates are identical, the numbers of different types of BSUs are all the same and the middle two elements of BSUs constitute a cycle, then no matter whether the system is periodic, or quasiperiodic, or aperiodic, or unordered, or even random, it will be transparent at the CW. The conclusion is confirmed by the numerical results. Similar to the even layers of neighbourhood identical elements in TCD method, such a kind of optical BSU subsystem can also be decimated from the chain in the process of transmission investigation. There would be a potential application in the designing of some interesting optical devices. 相似文献
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Jin-Xing TaYu-Ling Song Xuan-Zhang Wang 《Journal of magnetism and magnetic materials》2012,324(1):72-77
Transmission, refraction and absorption properties of an antiferromagnetic/ion-crystal superlattice are investigated. The transmission spectra based on FeF2/TlBr superlattices reveal that there exist two intriguing guided modes in a wide stop band. Additionally, FeF2/TlBr superlattices possess either the negative refraction or the quasi left-handedness, or even simultaneously hold them at certain frequencies of two guided modes, which require both negative magnetic permeability of antiferromagnetic layers and negative permittivity of ion-crystal layers. Frequency regimes of the guided modes will be dependent on the magnitude of the external magnetic field. Therefore, handedness and refraction properties of the system can be manipulated by modifying the external magnetic field. Absorption spectra exhibit that absorption corresponding to guided modes is noticeable. 相似文献
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Zheng-Hua Tang Zheng-Sheng Jiang Tao Chen Chun-Zhi Jiang Da-Jun Lei Jian-Quan Huang Feng Qiu Min Yao Xiao-Yi Huang 《Physics letters. A》2018,382(2-3):106-110
Anisotropic piezoelectric superlattices (APSs) with the periodic arrangement of polarized anisotropic piezoelectric domains in a certain direction are presented, in which the coupled polaritonic band gaps (CPBGs) can be obtained in the whole Brillouin Zone and the maximum relative bandwidth (band-gap sizes divided by their midgap frequencies) of can be achieved. The general characteristics of the APSs are similar to those of the phononic crystals composed of two types of materials, with the main difference being the formation mechanism of the CPBGs, which originate from the couplings between lattice vibrations along two different directions and electromagnetic waves rather than from the periodical modulation of density and elastic constants. In addition, there are no lattice mismatches because the APSs are made of the same material. Thus, the APSs can also be extended to the construction of novel acousto-optic devices. 相似文献
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Jarmila M??llerov?? Veronika Vavru??kov?? Pavel ??utta 《Central European Journal of Physics》2009,7(2):315-320
We report results obtained from measurements of optical transmittance spectra carried out on a series of silicon thin films
deposited by plasma-enhanced chemical vapour deposition (PECVD) from silane diluted with hydrogen. Hydrogen dilution of silane
results in an inhomogeneous growth during which the material evolves from amorphous hydrogenated silicon (a-Si:H) to microcrystalline
hydrogenated silicon (μc-Si:H). Spectral refractive indices and absorption coefficients were determined from transmittance
spectra. The spectral absorption coefficients were used to determine the Tauc optical band gap energy, the B factor of the Tauc plots, E
04 (energy at which the absorption coefficient is equal to 104 cm−1), and the Urbach energy as a function of the hydrogen dilution. The results were correlated with microstructure, namely volume
fractions of the amorphous and crystalline phase with voids, and with the grain size.
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P.S Erdman M Fajardo K.M Sando W.C Stwalley 《Journal of Quantitative Spectroscopy & Radiative Transfer》2004,88(4):447-481
Experimental results are reported for a unique spectroscopic device called the Plasma Spectroscopy Cell. Optical absorption of lithium metal vapor was observed at high density and temperature. Absorption spectra are analyzed using theoretical calculations of absorption cross sections for lithium-helium interactions, and singlet and triplet state transitions of diatomic lithium in the visible spectral range. This is believed to be the most complex example yet calculated in which absolute bound-bound, bound-free, free-bound, and free-free contributions for all possible optically allowed transitions are all included, in quite respectable agreement with experiment. 相似文献