共查询到20条相似文献,搜索用时 15 毫秒
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V. A. Volodin M. D. Efremov V. A. Sachkov 《Journal of Experimental and Theoretical Physics》2006,103(4):646-653
The technique of Raman spectroscopy has been used to investigate doped (n-type) and undoped GaAs/AlAs superlattices with AlAs barrier thicknesses from 17 to 1 monolayers. The peak corresponding to the scattering by a two-dimensional plasmon was found in the Raman spectrum of a doped superlattice with relatively thick barriers. The position of the experimental peak corresponded to the value calculated in the model of plasma oscillations in periodic planes of a two-dimensional electron gas. The electron tunneling effects played an increasingly prominent role as the AlAs barrier thickness decreased. The peaks corresponding to the scattering by coupled phonons with three-dimensional plasmons were found in the Raman spectra for a superlattice with an AlAs thickness of 2 monolayers; i.e., the delocalization of coupled modes was observed. In this case, the folding of acoustic phonons was observed in the superlattice under consideration, indicative of its good periodicity, while the localization of optical phonons in GaAs layers was observed in undoped superlattices with an AlAs thickness of 2 monolayers. 相似文献
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K. S. Zhuravlev A. M. Gilinskii T. S. Shamirzaev V. V. Preobrazhenskii B. R. Semyagin M. A. Putyato S. S. Chipkin 《Physics of the Solid State》1998,40(9):1577-1581
A study is reported of steady-and nonsteady-state photoluminescence of intentionally undoped and uniformly silicon-doped type-II
(GaAs)7(AlAs)9 superlattices grown by MBE simultaneously on (311)A-and (100)-oriented GaAs substrates. It has been established that at elevated temperatures (160>T>30 K) the superlattice spectra are dominated by the line due to the donor-acceptor recombination between donors in the AlAs
layers and acceptors located in the GaAs layers. The total carrier binding energy to the donor and acceptor in a pair has
been determined.
Fiz. Tverd. Tela (St. Petersburg) 40, 1734–1739 (September 1998) 相似文献
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V. A. Volodin M. D. Efremov V. V. Preobrazhenskii B. R. Semyagin V. V. Bolotov V. A. Sachkov E. A. Galaktionov A. V. Kretinin 《JETP Letters》2000,71(11):477-480
The phonon-plasmon interaction in tunneling GaAs n /AlAs m superlattices (m=5and 6≥n≥0.6 monolayers) was studied by Raman scattering spectroscopy. The interaction of optical phonons localized in GaAs and AlAs layers with quasi-three-dimensional plasmons strengthens as the thickness of GaAs quantum wells decreases and the electronic states in the superlattices become delocalized due to tunneling. It is assumed that the plasmons also interact with the TO-like phonon modes localized in quantum islands or in thin ruffled layers. 相似文献
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《Superlattices and Microstructures》2000,27(5-6):525-528
Cyclotron resonance (CR) measurements have been carried out to evaluate the effective mass of electron in (InGaAs)n/(GaAs)nsuperlattices (SLs) and (InGaAs)n/(AlAs)nSLs. To clarify the dependence of cyclotron mass on the monolayer numbern , we measured CR signals using pulsed high-magnetic fields up to 150 T and a far-infrared laser. We found clear cyclotron resonances in the transmission of 10.6 μ m at 75 T at room temperature in (InGaAs)n/(GaAs)nSLs and little dependence on the monolayer number n in the SLs. However, for (InGaAs)n/(AlAs)nSLs, a large dependence of cyclotron mass on the monolayer number n was observed. We consider that these dependencies are related to the difference between the barrier height in the SLs and the influence of nonparabolicity on the conduction subbands in the SLs. 相似文献
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The subband structure for electrons in Si/SiGe strained layer superlattices along the (100) direction is calculated self-consistently including many-body effects in the local density approximation. The strain induced splitting of the six-fold degenerate conduction band results in different potential wells for different valleys. The charge distribution between the layers and valleys is calculated versus carrier concentration and conduction band offset for different strains. An estimate for the band offsets is obtained by comparison of experimental results with the calculations. 相似文献
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V. F. Sapega V. I. Perel’ A. Yu. Dobin D. N. Mirlin I. A. Akimov T. Ruf M. Cardona K. Eberl 《JETP Letters》1996,63(4):305-310
The polarization characteristics of hot photoluminescence in GaAs/AlAs superlattices are investigated experimentally and theoretically.
It is shown that the formation of an electronic miniband in the superlattice substantially changes the polarization characteristics
of the photoluminescence. As a result of the quasi-three-dimensional character of the motion of hot electrons in the superlattice,
the polarization depends on the ratio of the electron kinetic energies in the plane of the superlattice and along the axis
of the superlattice.
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 4, 285–289 (25 February 1996) 相似文献
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《Superlattices and Microstructures》1994,15(4):405-407
We have theoretically investigated the valence-band discontinuity (ΔEv) at the (100) GaAs/AlAs interface with the InAs strained insertion-layer. The theoretical calculation is carried out by the self-consistent tight-binding method with the sp3s* basis in the (GaAs)5/(InAs)1/(AlAs)5/(InAs)1 [100] superlattice. ΔEv at the GaAs/InAs(1ML)/AlAs interface is calculated to be 0.50 eV, which is practically equal to ΔEv = 0.51 eV at the GaAs/AlAs interface with no InAs layers. The insertion of the InAs monolayer changes the detail of valence charge density at the GaAs/AlAs interface but does not change ΔEv. The result of calculation is in consistent with our experimental measurement by using the x-ray photoelectron spectroscopy. 相似文献