Molecular Beam Epitaxy
Mostrando 25-36 de 57 artigos, teses e dissertações.
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25. Variable range hopping conduction in low-temperature molecular beam epitaxy GaAs
Electric transport properties measured by Van der Pauw resistivity experiments of Low-Temperature Molecular Beam Epitaxy (LT-MBE) GaAs samples are used to identify a method to improve the resistivity of GaAs material. We present results on five samples grown at 265, 310, 315, 325, and 345 ºC. The electric measurements were carried out at temperatures rangin
Brazilian Journal of Physics. Publicado em: 2006-06
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26. Characterization of SnTe films grown by molecular beam epitaxy
A series of SnTe layers with thicknesses varying from 0.42 to 9.1 µm were grown by molecular beam epitaxy on (111) BaF2 substrates. The SnTe lattice parameter was found to be 6.331 Å as determined from x-ray diffraction spectra measured in the triple-axis configuration. The FWHM of the (222) SnTe x-ray rocking curves indicated a good crystalline quality an
Brazilian Journal of Physics. Publicado em: 2006-06
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27. InGaAs embedding of large InAs quantum dots obtained by pulsed in deposition for long-wavelength applications
In this work we studied the molecular-beam epitaxy of large InAs quantum dots embedded in an InGaAs quantum well. The formation of the quantum dots was performed by pulsed deposition of InAs material, simulating therefore a low deposition rate. Room-temperature photoluminescence experiments carried out on these samples showed intense emissions with a wavelen
Brazilian Journal of Physics. Publicado em: 2006-06
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28. Low frequency oscillations and bifurcation diagram in semi-insulating GaAs samples
We present an experimental study of bifurcation diagrams from low frequency current oscillations (LFO) measurements obtained from semi-insulating GaAs samples grown by low temperature molecular beam Epitaxy (LT-MBE). The considered growth temperatures were 215ºC and 265ºC. LFO are considered to be spontaneously generated oscillations under constant applied
Brazilian Journal of Physics. Publicado em: 2006-06
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29. Growth and structural characterization of PbTe/PbEuTe double barrier
A series of PbTe/PbEuTe double barrier samples with different barrier widths were successfully grown on BaF2 substrates by molecular beam epitaxy. The electron concentration of PbTe spacer and well layers was controlled by the deviation from stoichiometry, while the buffer and cap layers were intentionally doped with bismuth to obtain low-resistivity layers
Brazilian Journal of Physics. Publicado em: 2006-06
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30. Estruturas de barreira dupla de PbTe/PbEuTe crescidas por epitaxia de feixe molecular / PbTe/PbEuTe double barrier structures grown by molecular beam epitaxy
This work reports the growth of PbTe/Pb(1-x)Eu(x)Te double barrier (DB) structures by molecular beam epitaxial and the device processing aiming the resonant tunneling measurement. The samples were grown on (111) BaF(2) substrates at 300°C. Resistivity and Hall effect measurements were performed on reference films to determine the most suitable electrical pr
Publicado em: 2006
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31. MBE growth and characterization of films SnTe layers and SnTe/Sn1-x EuxTe heterostructures on BaF2 / Crescimento por MBE e caracterização de filmes SnTe e heteroestruturas de SnTe/Sn1-x EuxTe sobre BaF2
This work presents a systematic investigation of structural and electrical properties of SnTe epitaxial films grown on BaF2 substrates, as well as a study of structural properties of Sn1-xEuxTe (0
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/02/2005
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32. MBE growth and characterization of films SnTe layers and SnTe/Sn1-x EuxTe heterostructures on BaF2 / Crescimento por MBE e caracterização de filmes SnTe e heteroestruturas de SnTe/Sn1-x EuxTe sobre BaF2
Este trabalho tem por objetivo a investigação sistemática das propriedades estruturais e elétricas de filmes epitaxiais de SnTe crescidos sobre substratos de BaF2 (111), bem como o estudo das propriedades estruturais de filmes de Sn1-xEuxTe (0<xEu=0,12) crescidos sobre camadas intermediárias de SnTe pré-depositadas sobre substratos de BaF2 (111). As
Publicado em: 2005
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33. Characterization of PbTe p - n+ junction grown by molecular beam epitaxy
In this work we investigate the electrical properties of PbTe p - n+ junction. Mesa diodes were fabricated from p - n+ PbTe layers grown on (111) BaF2 substrates by molecular beam epitaxy. From the analysis of the current versus voltage characteristic measured at 80K, the incremental differential resistance and the series resistance were determined. The capa
Brazilian Journal of Physics. Publicado em: 2004-06
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34. Electrical properties of bi-doped PbTe layers grown by molecular beam epitaxy on BaF2 substrates
Resisistivity and Hall measurements were performed at temperatures from 10 to 320K on Bi-doped PbTe layers grown on (111) BaF2 by molecular beam epitaxy. Samples with electron concentration varying from 1x10(17) to 4x10(19)cm-3 were obtained. Results indicated that all offered Bi atoms in the vapor phase were effectively incorporated in the PbTe as active do
Brazilian Journal of Physics. Publicado em: 2004-06
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35. Magnetic field induced absorption in Pb xEu1-xTe magnetic semiconductors
We report an investigation of the optical absorption spectrum, using non-polarized light, in Pb xEu1-xTe, x=0 and x=0.095, epitaxial thick layers grown by molecular beam epitaxy (MBE). The absorption edge is described by a broad band, due to the electronic transitions from the 4f7 of Eu2+ to the states in 4f6 5d configuration, as seen previously in bulk Eu c
Brazilian Journal of Physics. Publicado em: 2004-06
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36. Hall effect in InAs/GaAs superlattices with quantum dots: identifying the presence of deep level defects
We have carried out van der Pauw resistivity and Hall effect measurements on a series of Molecular Beam Epitaxy InAs/GaAs superlattice samples containing InAs quantum dots. Three growth parameters were varied, the InAs coverage, the number of repetitions of the InAs/GaAs layers, and the GaAs spacer thickness. The results can be grouped in two sets, those sam
Brazilian Journal of Physics. Publicado em: 2004-06