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  1. 32 Acta Physica Polonica A
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  1. 2 2017
  2. 3 2016
  3. 6 2013
  4. 1 2012
  5. 5 2011
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  1. 33 Misiewicz J.
  2. 13 Sęk G.
  3. 9 Ryczko K.
  4. 7 Bryja L.
  5. 7 Kudrawiec R.
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1
Content available remote Lateral Coupling within the Ensemble of InAs/InGaAlAs/InP Quantum Dashes
100%
Ryczko K. , Sęk G. , Misiewicz J.
Acta Physica Polonica A
|
2013
|
tom 124
|
nr 5
805-808
EN
In this work we investigate the electronic structure of coupled quantum dashes. The respective confined state energy levels are calculated for various cross-sectional shapes and sizes of the dashes and in function of the lateral distance between them. The results are confronted with the existing experimental data on the optical transitions in such structures. It has been concluded that for realistic system parameters (geometry and spatial in-plane separation) the obtained direct coupling is weak and in most of the applications the dashes can be considered individually, as long as the ensemble is strongly inhomegeneous.
2
Content available remote An Investigation of Optical Vibrations in Zn_{3}P_{2}
100%
Misiewicz J. , Wrobel J. , Clayman B.
Acta Physica Polonica A
|
1991
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tom 79
|
nr 2-3
405-409
EN
Reflectivity and transmittivity spectra of Zn_{3}P_{2} in the far infrared region were measured at several temperatures. Raman scattering spectra at 295 K were also measured. Results of these measurements were interpreted in terms of one-phonon and multi-phonon transitions.
3
Content available remote Hopping Excitons in GaInNAs - Simulation οf Micro- and Macrophotoluminescence Spectra
100%
Baranowski M. , Latkowska M. , Kudrawiec R. , Misiewicz J.
Acta Physica Polonica A
|
2011
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tom 120
|
nr 5
899-901
EN
Model of hopping excitons has been applied to explain the origin of sharp lines observed in microphotoluminescence spectra of GaInNAs layers. It has been shown that shape of the micro- and macrophotoluminescence spectra results from the exciton hopping between localizing centers and this phenomenon is responsible for the observation of sharp lines in microphotoluminescence experiment. In addition, the influence of different model parameters on photoluminescence spectra and their characteristic parameters such as the Stokes shift and full width at half maximum has been investigated.
4
Content available Skyrmions in a Hole Gas with Large Spin Gap and Strong Disorder
88%
Bryja L. , Ryczko K. , Wójs A. , Misiewicz J. , Potemski M.
Acta Physica Polonica A
|
2006
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tom 110
|
nr 2
163-168
EN
In the photoluminescence excitation spectra of two-dimensional valence holes with large spin gap and strong disorder we find evidence for quantum Hall ferromagnetism and small skyrmions around the Landau level filling factorν=1. This interpretation is supported by numerical calculations.
5
Content available remote Monte Carlo Simulations of the Influence of Localization Centres on Carrier Dynamics in GaInNAs Quantum Wells
88%
Baranowski M. , Kudrawiec R. , Latkowska M. , Syperek M. , Misiewicz J.
|
|
nr 6
1022-1025
EN
Model of hopping excitons is applied to study the carrier dynamics in GaInNAs/GaAs quantum well system. Impact of parameters describing localizing states (i.e., an average energy and density) on carrier dynamics in GaInNAs material is investigated theoretically. It is shown how those parameters affect the quantities that can be extracted from time resolved photoluminescence experiments. It is shown that obtained simulations can be very helpful in the interpretation of the experimental data.
6
Content available remote Landauer Conductance of Generalized Fibonacci-Type Semiconductor Superlattices
88%
Salejda W. , Kubisa M. , Misiewicz J. , Ryczko K. , Tyc M.
Acta Physica Polonica A
|
1998
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tom 94
|
nr 3
514-518
EN
The quantum model of quasi-one-dimensional generalized Fibonacci semiconductor superlattice with the mass of charge carriers depending on the position in superlattice is formulated. The Landauer electrical conductance σ_{L} of generalized Fibonacci semiconductor superlattice is studied analytically and numerically. The dynamical maps allowing us to calculate σ_{L} of the studied systems are presented. It is shown that σ_{L} as a function of incident energy E of charge carriers oscillates strongly and exhibits the resonant character. We have verified numerically that σ_{L}(E) reaches its local maximum for energies E corresponding to energy eigenvalues of charges in superlattice.
7
Content available remote δ-Doped CdTe/Cd_{1-x}Mn_{x}Te Multiple Quantum Wells Investigated by Photoreflectance Spectroscopy
88%
Sitarek P. , Misiewicz J. , Karczewski G. , Wojtowicz T. , Kossut J.
Acta Physica Polonica A
|
1995
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tom 88
|
nr 5
901-904
EN
Room temperature photoreflectance spectroscopy was used to investigate CdTe/Cd_{1-x}Mn_{x}Te multiple quantum wells grown by MBE. Structures were indium δ-doped into the well or into the barrier. The value of heavy and light hole subbands splitting was measured and compared to the calculated ones. The influence of the position of δ-doping on the measured spectra was shown.
8
Content available Metastability of Band-Gap Energy in GaInNAs Compound Investigated by Photoreflectance
88%
Kudrawiec R. , Misiewicz J. , Pavelescu E. , Konttinen J. , Pessa M.
Acta Physica Polonica A
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2004
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tom 106
|
nr 2
249-263
EN
The band-gap energy of GaInNAs layers lattice-matched to GaAs substrate and annealed under different temperatures is investigated by photoreflectance spectroscopy. Different nitrogen nearest-neighbor environments of N atom appear in GaInNAs layers due to the post-growth annealing. It leads to an energy-fine structure of the band gap, i.e. well separated photoreflectance resonances related to different nitrogen nearest-neighbor environments (N-Ga_{4-m}In_m (0≤ m≤ 4) short-range-order clusters). The temperature dependence of the band gap E(T) related to different N-Ga_{4-m}In_m clusters is investigated in 10-280 K temperature range, and Varshni and Bose-Einstein parameters for E(T) are determined.
9
Content available remote Electronic Structure of Elongated In_{0.3}Ga_{0.7}As/GaAs Quantum Dots
88%
Pieczarka M. , Musiał A. , Podemski P. , Sęk G. , Misiewicz J.
Acta Physica Polonica A
|
2013
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tom 124
|
nr 5
809-812
EN
In this contribution the electronic structure of large In_{0.3}Ga_{0.7}As/GaAs quantum dots is studied theoretically by means of 8 band k · p modeling. These quantum dots constitute unique physical system due to the low strain limit of the Stranski-Krastanow growth mode resulting in relatively large physical volume and elongation of the quantum dots in [1-10] direction. As a result of these critical growth conditions the electronic structure is expected to be very sensitive to the nanostructure size, shape, and composition of the quantum dot as well as the accompanying wetting layer. Another peculiarity of investigated system is the confining potential which is rather shallow and weakened in comparison to standard quantum dots. It makes them very interesting in view of both fundamental study and potential applications. To reveal physical mechanisms determining the optical properties of the investigated system, the electronic structure, mainly the number of confined states, and the wave function extension as a function of both quantum dot size and geometry have been simulated numerically and the importance of electron-hole Coulomb interactions has been evaluated.
10
Content available remote Optical Transitions between Confined and Unconfined States in p-Type Asymmetric GaAs/InGaAs/AlGaAs QW Structures
88%
Sitarek P. , Ryczko K. , Misiewicz J. , Reuter D. , Wieck A.
Acta Physica Polonica A
|
2011
|
tom 120
|
nr 5
849-851
EN
We present contactless surface photovoltage spectroscopy and photoreflectance studies of 10 nm wide, p-type doped asymmetric GaAs/InGaAs/AlGaAs quantum well structures. The MBE grown structures differ in spacer thickness between the quantum well and the reservoir of holes. The doping causes that quantum well is placed in electric field. The surface photovoltage spectroscopy measurements gave us detailed information about the optical transitions between confined states and between confined and unconfined states. The comparison of experimental and numerical analysis allows us to identify all features present in the surface photovoltage spectroscopy and photoreflectance spectra. It has been found that spacer layer thickness has significant influence on surface photovoltage spectroscopy spectra.
11
Content available remote Near IR Refractive Index for GaInN Heavily Doped with Silicon
75%
Cywiński G. , Kudrawiec R. , Rzodkiewicz W. , Kryśko M. , Litwin-Staszewska E. , Misiewicz J. , Skierbiszewski C.
Acta Physica Polonica A
|
2009
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tom 116
|
nr 5
936-938
EN
The authors report on growth and results of infrared measurements of GaInN heavily doped with silicon. The lattice matched to GaN epitaxial layer of Ga_{0.998}In_{0.002}N:Si has been grown in plasma assisted molecular beam epitaxy in the metal rich conditions. The room temperature Hall concentration and mobility of electrons are 2× 10^{20} cm^{-3} and 67 cm^{2}/(Vs), respectively. The refractive index has been determined by variable angle spectroscopic ellipsometry. The refractive index exhibited a significant reduction of its value (from 2.25 to 2 at 1.55 μm) at near IR range where are the main interests of potential applications for nitride based intersubband devices. Reported here values of refractive indices at 1.55 and 1.3 μm are appropriate for fabrication of cladding layers with the required contrast to GaN for intersubband devices. The observed drop of refractive index is attributed to the carrier-induced plasma edge effect, which has been directly observed in reflectance spectrum.
12
Content available remote Interface and Surface Subsignals in Photoreflectance Spectra for GaAs/SI-GaAs Structures
75%
Jezierski K. , Sitarek P. , Misiewicz J. , Panek M. , Ściana B. , Korbutowicz R. , Tłaczała M.
Acta Physica Polonica A
|
1995
|
tom 88
|
nr 4
751-754
EN
Photoreflectance spectra were measured at room temperature for ener­gies in the vicinity of the E_{0} critical point for p-type as well as n-type doped GaAs/SI-GaAs structures. Depending on the doping concentration the ex­istence of two photoreflectance subsignals was observed; the first one arises from the surface space charge region while the second one from the interface region. The decomposition of photoreflectance spectrum into surface and in­terface subsignals was based on the photoreflectance measurements carried out for different wavelengths of the laser pump beam.
13
Content available remote New Numerical Matrix Methods of Solving the Quasi-One-Dimensional Effective-Mass Equation
75%
Salejda W. , Tyc M. , Andrzejewski J. , Kubisa M. , Misiewicz J. , Just M. , Ryczko K.
Acta Physica Polonica A
|
1999
|
tom 95
|
nr 6
881-896
EN
New efficient numerical methods of computing eigenvalues and eigenvectors of quasi-one-dimensional effective-mass Hamiltonian with arbitrary coordinate dependence of charge carrier mass are presented. Within the proposed approach the effective-mass equation is replaced by a nonsymmetric or symmetric matrix eigenproblem which can be analysed numerically with the help of existing computer routines. The presented methods are verified in special semiconductor heterostructure cases that are solvable within other approaches. A generalization of the presented methods for nonparabolic materials is also discussed.
14
Content available remote Hole Subband Mixing and Polarization of Luminescence from Quantum Dashes: A Simple Model
75%
Kaczmarkiewicz P. , Musiał A. , Sęk G. , Podemski P. , Machnikowski P. , Misiewicz J.
Acta Physica Polonica A
|
2011
|
tom 119
|
nr 5
633-636
EN
In this paper, we address the problem of luminescence polarization in the case of nanostructures characterized by an in-plane shape asymmetry. We develop a simple semi-qualitative model revealing the mechanism that accounts for the selective polarization properties of such structures. It shows that they are not a straightforward consequence of the geometry but are related to it via valence subband mixing. Our model allows us to predict the degree of polarization dependence on the in-plane dimensions of investigated structures assuming a predominantly heavy hole character of the valence band states, simplifying the shape of confining potential and neglecting the influence of the out-of-plane dimension. The energy dependence modeling reveals the importance of different excited states in subsequent spectral ranges leading to non-monotonic character of the degree of polarization. The modeling results show good agreement with the experimental data for an ensemble of InAs/InP quantum dashes for a set of realistic parameters with the heavy-light hole states separation being the only adjustable one. All characteristic features are reproduced in the framework of the proposed model and their origin can be well explained and understood. We also make some further predictions about the influence of both the internal characteristics of the nanostructures (e.g. height) and the external conditions (excitation power, temperature) on the overall degree of polarization.
15
Content available remote Nonlinear Zeeman Splitting of Holes in Doped GaAs Heterostructures
75%
Kubisa M. , Ryczko K. , Jadczak J. , Bryja L. , Misiewicz J. , Potemski M.
Acta Physica Polonica A
|
2011
|
tom 119
|
nr 5
609-611
EN
Polarization-resolved photoluminescence from two-dimensional GaAs/GaAlAs heterostructures doped with acceptors was studied in high magnetic fields. Measurements were carried out in low temperatures up to 2 K and magnetic field up to 21 T. Experiments performed in the Faraday configuration enabled to resolve hole states with different spin orientation. We observed a nonlinear behavior of valence-band g factor in strong magnetic fields. To explain obtained results, a detailed theoretical calculation was carried out based on the Luttinger model for valence-band states. We examined the spin splitting of hole levels under the influence of both external magnetic field and built-in electric field existing in doped heterostructures. Changes of hole g factor with the width of the structure and the density of two-dimensional carriers are discussed.
16
Content available remote Fine Structure of the Localized Emission from GaInNAs Layers Studied by Micro-Photoluminescence
75%
Kudrawiec R. , Latkowska M. , Sęk G. , Misiewicz J. , Ibáñez J. , Henini M. , Hopkinson M.
Acta Physica Polonica A
|
2009
|
tom 116
|
nr 5
930-932
EN
GaInNAs bulk-like layers ( ≈ 20% In and ≈ 3% N) grown on GaAs substrate with various crystallographic orientations have been studied by micro-photoluminescence at low temperatures for a broad range of excitation conditions. In addition to photoluminescence peaks, which are associated with heavy- and light-hole free exciton recombination, a band of sharp lines was observed below the fundamental free exciton transition at low excitation. It shows that the localized emission which is typical of this alloy at low temperatures is composed of individual narrow photoluminescence lines which are associated with the recombination of single excitons. They can be localized on various local potential minima including those originating from the alloy content fluctuations and/or deep acceptor(donor)-like complexes.
17
Content available remote Combined Exciton-Cyclotron Resonance in Photoluminescence of a Two-Dimensional Hole Gas
75%
Jadczak J. , Bryja L. , Płochocka P. , Wójs A. , Misiewicz J. , Maude D. , Potemski M.
Acta Physica Polonica A
|
2009
|
tom 116
|
nr 5
852-853
EN
A two-dimensional hole gas in an asymmetric GaAs/Ga_{1-x}Al_{x}As quantum well is studied by polarization-resolved photoluminescence in high magnetic fields (up to B = 20 T) and at low temperatures (down to T = 50 mK). In addition to the previously reported dominant emission channels of various free and acceptor-bound trions, the high-energy hole cyclotron replicas of the bound states are now also observed, corresponding to the combined exciton-cyclotron resonance. Identification of different transitions in the rich, multi-peak spectra was possible by the analysis of optical selection rules and comparison of the experimental spectra with realistic numerical calculations.
18
Content available remote Experimental and Theoretical Studies of Free and Acceptor-Bound Positive Magneto-Trions
75%
Bryja L. , Wójs A. , Płochocka-Polack P. , Gładysiewicz A. , Misiewicz J. , Potemski M.
Acta Physica Polonica A
|
2007
|
tom 112
|
nr 2
415-418
EN
By combination of polarization-resolved photoluminescence, transport, and realistic numerics we study energy and recombination spectra of free and acceptor-bound positive trions in a quasi-two-dimensional hole gas. The singlet-triplet crossing in the trion ground state is found at B≈12 T, and a slight reduction of all trion binding energies coincident with the formation of a Laughlin hole fluid is observed at B≈14.2 T.
19
Content available remote InAs on InP Quantum Dashes as Single Photon Emitters at the Second Telecommunication Window: Optical, Kinetic, and Excitonic Properties
75%
Mrowiński P. , Dusanowski Ł. , Somers A. , Höfling S. , Reithmaier J. , Misiewicz J. , Sęk G.
Acta Physica Polonica A
|
2017
|
tom 132
|
nr 2
382-386
EN
In this work, InAs/InGaAlAs/InP quantum dashes have been investigated in terms of their optical, kinetic, and excitonic properties with respect to their application within the 1300± 40 nm spectral range, i.e. the O-band of the telecommunication technologies. We focused on the basic excitonic complexes such as neutral exciton, biexciton, and charged exciton, which have been identified by means of photoluminescence measurements. Emission and carriers' dynamics have been analyzed using rate equation model and fitting the experimental data obtained for both continuous-wave and pulsed excitation regimes. There has been found a significant impact of the charge carrier imbalance in the system and electron capturing rate on the dynamics of the optical and electronic transitions, which results in a high occupation of the negatively charged trion state. Autocorrelation measurements show clear antibunching of trion emission for non-resonant excitation which indicates a potential of such kind of emitters as single photon sources for short-range quantum communication schemes.
20
Content available Shake-Up Processes in Photoluminescence of Two-Dimensional Holes in a High Magnetic Field
75%
Wójs A. , Bryja L. , Misiewicz J. , Potemski M. , Reuter D. , Wieck A.
Acta Physica Polonica A
|
2006
|
tom 110
|
nr 3
429-435
EN
Recombination of excitons and positive trions is studied by two-beam photoluminescence of a two-dimensional hole gas in a high magnetic field. The singlet, dark-triplet and bright-triplet states of a free trion are resolved, and their binding energies are determined. Recombination of acceptor-bound trions is also detected, including a low-energy cyclotron replica, corresponding to a hole shake-up process. Identification of all these different transitions was possible by analysis of optical selection rules and the comparison of experimental spectra with realistic numerical calculations.
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