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GaAs Structure (gaa + structure)

Distribution by Scientific Domains
Physics and Astronomy75%

Selected Abstracts

Location of Mn sites in ferromagnetic Ga1,xMnxAs studied by means of X-ray diffuse scattering holography

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 5 2006
M. Kopecký
A three-dimensional image of the local neighbourhood of Mn atoms in a Ga1,xMnxAs (x = 0.02) layer has been obtained by using X-ray diffuse scattering holography. The first and second nearest neighbours of the Mn atoms correspond to the local structure around Ga atoms in the zinc-blende GaAs structure. Accordingly, the Mn atoms are situated in substitutional positions. [source]

Fast measurements of photoreflectance spectra by using multi-channel detector

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 5 2009
R. Kudrawiec
Abstract Photoreflectance (PR) measurements were performed on GaAs- and GaN-based structures in the so called ,bright configuration' where the sample was illuminated by white light (probing beam) instead of monochromatic light as it takes place in the standard configuration, i.e., so-called ,dark configuration'. Within this concept the whole PR spectrum can be measured/processed at the same time using a multi-channel detector (i.e., CCD camera) instead the phase sensitive lock-in detection system with the one-channel detector. In this work PR spectra for Si ,-doped GaAs structure have been measured using both the CCD detector system as well as the standard lock-in technique with the one-channel detector system. GaAs-related Franz,Keldysh oscillations, which are typical of Si ,-doped GaAs structure, have been clearly observed in PR spectra measured by using the two detection systems. In addition, the PR system with the CCD detector has been used to measure PR spectra in the UV spectral region for an InGaN/GaN/Al2O3 structure. In this case, PR resonances related to InGaN and GaN band gap absorption have been clearly observed. Using the PR system with CCD detector the time of PR measurements was reduced to few seconds for both GaAs- and GaN-based structures. It shows that the bright configuration of PR set-up with multi-channel detection system is very promising and perspective in the fast diagnostic of semiconductor structures. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Possible anomalous Hall effect of Be/Si pair delta-doped GaAs structures

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 9 2008
J. P. Noh
Abstract Beryllium/Silicon pair delta-doped GaAs structures grown by molecular-beam epitaxy exhibit Hall resistance which has highly nonlinear dependence on the applied magnetic field. The dependence of the occurrence of the nonlinear Hall resistance on the sample structure is investigated. A significantly large increase in the non-linearity and magnitude of the Hall resistance is observed from a sample structure whose buffer layer is grown under the low As flux and thick buffer layer condition. The non-linearity of the Hall resistance is found to depend on a single parameter B /T, where B and T are the magnetic field and temperature, respectively. From another sample structure in which an AlGaAs barrier with a single Be delta-doped layer is placed near the Be/Si pair delta-doped layer, a similar nonlinear Hall resistance is observed. On the basis of these results, it is suggested that the anomalous Hall effect results from interplay between itinerant holes in the valence band and localized spins in the delta-doped layer in these structures. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]