Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 10

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Current Fluctuations in Single Barrier Vertical GaAs/AlAs/GaAs Tunneling Devices

100%
Przybytek J., Baj M.
Acta Physica Polonica A
|
2007
|
vol. 112
|
issue 2
221-226
EN
We report the experimental results of the low temperature (T = 4.2 K) low-frequency current fluctuations measurements in the single-barrier resonant tunneling GaAs/AlAs/GaAs device with Siδ-doping in the center of the 10 nm thick AlAs barrier. The dimensions of the device were 200μm by 200μm. For the biasing voltages 0.1 V<|U|<1 V we observed the Fano factors between F = 0.7 and F = 0.95. We explain it by the existence of the trapping centers/imperfections/resonant levels inside the barrier participating in the transport for this range of voltages. Only for the smallest biasing voltages the Fano factor tends to F = 1, expected for a highly nontransparent barrier.
2
Content available remote

Stabilization of the Distorted Configuration of the EL2 Defect Induced by the Free Electron Capture in GaAsP

81%
Przybytek J., Baj M., Słupiński T.
Acta Physica Polonica A
|
1995
|
vol. 88
|
issue 5
881-884
EN
Our results of optical absorption, electronic transport and deep level transient spectroscopy measurements performed on n-type GaAs_{1-x}P_{x} (x ≈ 0.2) strongly suggest that using both an enlarged-gap material (compared to GaAs) and hydrostatic pressure we can push down the acceptor level of the distorted configuration of the EL2 defect, (EL2*)^{–/0}, sufficiently low into the gap that the distorted configuration of the EL2 defect, EL2*, becomes stabilized.
3
Content available remote

On the Pinning of the Fermi Level by Germanium A_{1}^{0/+} Deep Donor State in GaAs Codoped with Ge and Te

81%
Słupiński T., Nowak G., Przybytek J., Stępniewski R.
Acta Physica Polonica A
|
1993
|
vol. 84
|
issue 4
807-811
EN
We present the possibility of GaAs:Ge,Te crystals growth from the melt (liquid encapsulated Czochralski method) with partially occupied, at ambient pressure, the A_{1} localized electronic state of Ge_{Ga} impurity. In as-grown crystals the amphotericity of Ge and creation of defects (deep acceptor complexes, precipitates etc.) during cooling after growth limit the free electron concentration below the value necessary to populate the A_{1}^{0/+} level. Special annealing of the samples, which enlarges the free electron concentration, was used. The occupation of A_{1}^{0/+} level, at ambient pressure, was observed by pressure dependent Hall effect measurements.
4
Content available remote

Hydrostatic Pressure Study of MBE CdMnTe Doped with Bromine

71%
Szczytko J., Wasik D., Przybytek J., Baj M., Waag A.
Acta Physica Polonica A
|
1995
|
vol. 88
|
issue 5
933-936
EN
We present Hall effect and resistivity measurements as a function of pressure performed on MBE-grown Cd_{1-x}Mn_{x}Te (with x = 0.14) layer (1 μm) doped with bromine. The experimental data were analysed using positive and negative U model of the Br centres. We found that both models could reproduce the experimental points, but in the case of positive U model - only under assumption that the sample was completely uncompensated.
5
Publication available in full text mode
Content available

High-Pressure Magnetotransport Measurements of Resonant Tunnelling via X-Minimum Related States in AlAs Barrier

71%
Gryglas M., Przybytek J., Baj M., Eaves L., Henini M.
Acta Physica Polonica A
|
2001
|
vol. 100
|
issue 3
403-408
EN
In this paper, we present the results of magnetotransport experiments performed on a single barrier GaAs/AlAs/GaAs heterostructures. Tunnel current was measured as a function of magnetic field for different values of bias voltage and hydrostatic pressure. We observed that the amplitude of the magnetooscillations of tunnel current quenched when the requirements for resonant tunnelling were met and it recovered in out-of-resonance conditions. This effect was observed both for tunnelling through donor states and through X-minimum related quasiconfined conduction band states. The fact that also in the latter case the amplitude was restored suggests that this process involved X_z subbands and took place without a participation of phonons (the so-called k_ǁ-conserving process).
6
Content available remote

Observation of Thermally-Activated Electron Traps in GaAs/AlAs/GaAs Heterostructures in Low-Frequency Noise Measurements

62%
Przybytek J., Stankiewicz R., Gryglas-Borysiewicz M., Baj M., Cavanna A., Faini G.
Acta Physica Polonica A
|
2011
|
vol. 119
|
issue 5
723-725
EN
During our investigations of tunneling process in thin 7 nm thick GaAs/AlAs/GaAs vertical single-barrier tunneling structure with Si δ-doping inside the barrier we have observed fluctuations of the tunneling current which exhibited large Lorentzian noise with intensity depending on biasing voltage. We have shown that Lorentzian noise originates from multilevel random telegraph noise of the small number of fluctuators which influence the tunneling process. Time-domain analysis of the current noise measured for temperatures between 4.2 K and 50 K enabled to determine the thermal activation energies of these fluctuators lying between 0.8 and 3 meV.
7
Content available remote

Hydrostatic-Pressure Deep Level Transient Spectroscopy Study of the Heteroantisite Antimony Level in GaAs

62%
Babiński A., Przybytek J., Baj M., Omling P., Samuelson L., Słupiński T.
Acta Physica Polonica A
|
1992
|
vol. 82
|
issue 5
841-844
EN
We present some preliminary results of the first hydrostatic-pressure study of the electronic level related to the Sb-heteroantisite defect in GaAs. We studied two kinds of n-type GaAs samples doped with antimony: bulk samples grown by liquid encapsulated Czochralski method and thin layers grown by metalorganic chemical vapour deposition technique. We found strongly nonlinear pressure dependence of the activation energy of the emission rate for the level. Moreover, the results obtained for the bulk material were fairly different from those obtained for thin metalorganic chemical vapour deposition layers. The possible explanation of this difference is presented.
8
Content available remote

Influence of Epitaxial Strain on Magnetic Anisotropy in (Ga,Mn)As

62%
Juszyński P., Wasik D., Gryglas-Borysiewicz M., Przybytek J., Szczytko J., Twardowski A., Sadowski J.
Acta Physica Polonica A
|
2012
|
vol. 122
|
issue 6
1004-1006
EN
Two (Ga,Mn)As samples having different magnetic anisotropy (one with in-plane easy axis and another one with out-of-plane easy axis) were studied by means of magnetotransport experiments. Anisotropy field B_{A} was determined for both samples as a function of temperature. For the sample having in-plane easy axis, an inversion of the direction of planar Hall effect hysteresis was observed upon increase of temperature. This result was simulated using the Stoner-Wohlfarth model.
9
Content available remote

Transport in GaAs/AlAs/GaAs [111] Tunnel Junctions

62%
Lewińska S., Gryglas-Borysiewicz M., Przybytek J., Baj M., Jouault B., Gennser U., Ouerghi A.
Acta Physica Polonica A
|
2011
|
vol. 119
|
issue 5
606-608
EN
Resonant tunneling in single-barrier GaAs/AlAs/GaAs junctions grown in [111] direction was studied for samples with different concentration of silicon δ-doping in AlAs. In the I(V) characteristics, measured at 4 K, two kinds of peaks were observed: related to resonant tunneling via donors states in the barrier, and through X-minimum quantum well subbands. The results are compared to those previously obtained for analogous samples grown along [001] direction. The investigations reveal different symmetry of donor states in both cases.
10
Content available remote

Spatial Correlations of Donor Charges in MBE CdTe

52%
Suski T., Wiśniewski P., Litwin-Staszewska E., Wasik D., Przybytek J., Baj M., Karczewski G., Wojtowicz T., Zakrzewski A., Kossut J.
Acta Physica Polonica A
|
1995
|
vol. 88
|
issue 5
929-932
EN
We present experimental evidence that at high pressures indium donors in CdTe localize electrons in spatially correlated manner. We have studied Hall mobility, μ_{H}, as a function of electron concentration, n_{H}, at T=77 K. Changes of n_{H} have been achieved by two methods. High pressure freeze-out of electrons onto localized states of In-donors leads to the mobility enhancement with respect to the situation when n_{H} has been modified by means of a subsequent annealing of the sample. As a result, depending on the degree of spatial correlations in the impurity charges arrangement, different values of μ_{H} correspond to the same value of n_{H}. The variation of mobility with electron concentration suggests that the localized state of In-donor represents likely negatively charged DX state.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.