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Tytuł:
Komputerowe wspomaganie projektowania zmechanizowanych obudów ścianowych według metody Zakładu Remontowo-Produkcyjnego KW S.A.
Computer aided design of powered roof supports according to method of Zakład Remontowo-Produkcyjny KW S.A.
Autorzy:
Karczewski, T.
Czarnota, P.
Powiązania:
https://bibliotekanauki.pl/articles/113740.pdf
Data publikacji:
2016
Wydawca:
STE GROUP
Tematy:
obudowa zmechanizowana
optymalizacja
proces projektowania
układ lemniskatowy
powered roof support
optimization
design process
lemniscate mechanism
Opis:
Prezentacja autorskiego programu obliczeniowego Zakładu Remontowo-Produkcyjnego, którego zadaniem jest usprawnienie procesu projektowania obudowy zmechanizowanej.
Presentation of Zakład Remontowo-Produkcyjny’s copyright calculation program, tasked with improving of the design of powered roof support.
Źródło:
Systemy Wspomagania w Inżynierii Produkcji; 2016, 1 (13); 407-417
2391-9361
Pojawia się w:
Systemy Wspomagania w Inżynierii Produkcji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Doping and Characterization of Wide-Gap II-VI Epilayers
Autorzy:
Karczewski, G.
Wojtowicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/1946648.pdf
Data publikacji:
1996-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.55.Ln
71.55.-i
71.55.Gs
Opis:
In this paper we review the properties of n-type doped ZnSe and CdTe epilayers grown by molecular beam epitaxy on (100) GaAs substrates. Recent results of photoluminescence, transport measurements, secondary ion mass spectroscopy and deep-level transient spectroscopy are discussed. A major emphasis is placed on the effect of different dopant species and the role of the deviation from stoichiometry on the doped epitaxial layers. Since deep defect states play an important role in determining the properties of the doped materials, considerable attention is directed towards characterization and identification of deep-lying defect states, both native and introduced by dopants. In particular, in the case of ZnSe the deep-level transient spectroscopy results clarify why Cl is superior to Ga as an effective n-type dopant. They provide strong evidence that chlorine - unlike Ga - does not introduce by itself any detectable deep defects into the ZnSe lattice. In the case of CdTe, we focus on the influence of the deviation from stoichiometric growth conditions in the molecular beam epitaxy process and on the properties of In doped layers. We discuss resistivity, Mn diffusivity and the presence of various deep defects in layers grown at different Cd/Te flux ratios.
Źródło:
Acta Physica Polonica A; 1996, 90, 4; 635-644
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Operational malfunctions of turbochargers – reasons and consequences
Niesprawności eksploatacyjne turbosprężarek, ich przyczyny i skutki
Autorzy:
Dziubak, T.
Karczewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/134174.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
combustion engine
intake system
turbocharger
operational malfunctions
silnik spalinowy
układ dolotowy
turbosprężarka
niesprawności eksploatacyjne
Opis:
The paper discusses the most frequently occurring types of damage in turbochargers fitted in modern combustion engines and their influence on the engine basic operational indexes. The following causes of turbocharger malfunctions have been discussed: no lubrication, low lubricant pressure, reduced lubricant quality, foreign objects in the charged air and in the exhaust gas. Example malfunctions resulting from the said causes have been shown. The experimental part discusses the influence of a reduction of the charging pressure resulting from a leakage in the intake system on the effective parameters of a diesel engine fitted in light-duty and heavy-duty vehicles. The leakage in the intake system has been simulated by boring holes of the diameter of 3 and 12 mm in the intake manifold downstream of the turbocharger. The influence has been determined of the leakage of the turbocharging system on the value of the charging pressure, maximum effective power, engine torque, unit and hourly fuel consumption and the concentration of the exhaust components. A significant impact has been observed of the leakage of the turbocharging system on the effective parameters of the tested diesel engine and exhaust gas composition.
W artykule wskazano najczęściej występujące uszkodzenia turbosprężarek stosowanych we współczesnych silnikach spalinowych oraz przedstawiono ich wpływ na podstawowe wskaźniki operacyjne silników. Omówiono takie niesprawności turbosprężarek, jak: brak smarowania lub zbyt małe ciśnienie czynnika smarującego, jakość oleju smarującego, obecność ciał obcych w powietrzu i w spalinach. Przedstawiono przykładowe niesprawności spowodowane poszczególnymi czynnikami. W części doświadczalnej oceniono wpływ zmniejszenia ciśnienia doładowania spowodowanego nieszczelnością układu dolotowego na parametry użyteczne silnika o zapłonie samoczynnym, stosowanego w samochodach dostawczych oraz osobowych. Nieszczelność układu dolotowego została zamodelowana przez wykonanie otworów o średnicy 3 i 12 mm w kolektorze dolotowym za turbosprężarką. Określono wpływ nieszczelności układu doładowania na wartość ciśnienia doładowania, maksymalną moc użyteczną, moment obrotowy silnika, jednostkowe i godzinowe zużycie paliwa oraz stężenie składników toksycznych w spalinach. Stwierdzono istotny wpływ nieszczelności układu doładowania na parametry użyteczne i skład spalin silnika o zapłonie samoczynnym.
Źródło:
Combustion Engines; 2016, 55, 1; 13-21
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kolorymetryczne oznaczanie cynku w wodzie z użyciem dwu-b-naftylotiokarbazonu (DBN)
Colorimetric estimation of zinc in water with di-b-naphthylthiocarbazone (DBN)
Autorzy:
Karczewski, J.
Januszko, T.
Powiązania:
https://bibliotekanauki.pl/articles/871746.pdf
Data publikacji:
1977
Wydawca:
Narodowy Instytut Zdrowia Publicznego. Państwowy Zakład Higieny
Tematy:
wskazniki kolorymetryczne
zawartosc cynku
cynk
woda
dwu-b-naftylotiokarbazon
odczynniki
Źródło:
Roczniki Państwowego Zakładu Higieny; 1977, 28, 1
0035-7715
Pojawia się w:
Roczniki Państwowego Zakładu Higieny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ferroelectric Field Effect Transistor Based on Modulation Doped CdTe/CdMgTe Quantum Wells
Autorzy:
Kolkovsky, V.
Wojciechowski, T.
Wojtowicz, T.
Karczewski, G.
Powiązania:
https://bibliotekanauki.pl/articles/1811945.pdf
Data publikacji:
2008-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
77.80.-e
77.80.Fm
85.50.Gk
73.61.Ga
Opis:
In this work, we observed effects of changing the electron concentration and electron mobility upon the poling of the $Cd_{0.96}Zn_{0.04}Te$ ferroelectric gate deposited on the top of the CdTe-based modulation doped quantum well structure, which are confirmation of the existence of the electrostatic field originating from the ferroelectric material, which can be controlled by an external voltage. The analysis of the data obtained from the Hall effect measurements showed that the electron mobility and carrier concentration decreased by a factor of 2.5 and 1.5, respectively upon the negative poling of the gate with respect to the poled by the positive voltage. Moreover, the electrostatic field, depending on its directions, causes depletion of accumulation of electrons in the 2D channel, i.e., it is a source of the field effect.
Źródło:
Acta Physica Polonica A; 2008, 114, 5; 1173-1178
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oznaczanie jodu w moczu z zastosowaniem metody ekstrakcji butanolem
Opredelenie jjoda v moche s primeneniem metoda ehkstrakcii butanolom
Iodine determination in urine using the method of butanol extraction
Autorzy:
Karczewski, J.
Januszko, T.
Suszczyńska-Falecka, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2188622.pdf
Data publikacji:
1979
Wydawca:
Polskie Towarzystwo Diagnostyki Laboratoryjnej
Źródło:
Diagnostyka Laboratoryjna; 1979, 15, 5; 229-234
0867-4043
Pojawia się w:
Diagnostyka Laboratoryjna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Search for Dimensional Effects in Spin-Glass Transition in Thin Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te Multilayers
Autorzy:
Sawicki, M.
Dietl, T.
Skośkiewicz, T.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1943818.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Rr
75.50.Lk
75.30.Kz
75.50.-y
Opis:
SQUID magnetic measurements of CdTe/Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te, x ≃ 0.5, multi-layers with different CdMnTe layer thickness w reveal the persistence of the spin-glass irreversibilities down to ≃ 16 Å thin layers, i.e., well beyond the previously postulated 40 Å as a quasi-2D threshold. The freezing temperature T$\text{}_{f}$ is found to be a monotonic function of w, and it obeys a scaling law T$\text{}_{f}$ ∝ w$\text{}^{a}$, with a 0.8 similar to that for canonical spin-glasses. Magnetic properties of all studied structures are found to be independent of the orientation of the magnetic field.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 1038-1042
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Graded Quantum Well Structures Made of Diluted Magnetic Semiconductors
Autorzy:
Wojtowicz, T.
Kutrowski, M.
Karczewski, G.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1968998.pdf
Data publikacji:
1998-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.20.Dx
78.55.Et
Opis:
In this paper we review results of studies of two types of spatially graded quantum well structures containing various layers of diluted magnetic semiconductors Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te or Cd$\text{}_{1-x-y}$Mn$\text{}_{x}$Mg$\text{}_{y}$Te. The design of the structures has been recently proposed by us and suitable samples have been grown by a modified molecular beam epitaxy method. In the structures of the first type a digital profiling of the composition of the constituent material in the growth direction allowed to produce quantum wells with a specifically required shape of the confining potential (including parabolic, half-parabolic, triangular, and trapezoidal). Such samples were used for (i) determination of the conduction and valence band offsets in MnTe/CdTe and MgTe/CdTe systems, (ii) for the demonstration of an enhanced exciton binding in a parabolic confining potential as well as for (iii) demonstration of the possibility of "spin-splitting engineering" in diluted magnetic semiconductors quantum structures. In the second type of the structures, a precise in-plane profiling of either quantum well width or the barrier width or n-type doping intensity was realized. These structures were subsequently used for studies of the evolution of optical spectra with an increase in the concentration of confined two-dimensional gas of conduction electrons.
Źródło:
Acta Physica Polonica A; 1998, 94, 2; 199-217
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stimulated and Laser Emission in CdZnTe/CdMnTe Double Quantum Well Heterostructures
Autorzy:
Kowalczyk, L.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1933829.pdf
Data publikacji:
1995-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.45.+h
71.55.Gs
Opis:
Stimulated emission by optical excitation has been investigated in CdZnTe/CdMnTe quantum well heterostructures. Laser action has been achieved at 4.2 K and at 77 K with relatively low threshold values of the excitation intensity. Photοluminescence excitation spectra of the stimulated emission were obtained indicating that the optical gain involves exciton-exciton inelastic scattering.
Źródło:
Acta Physica Polonica A; 1995, 88, 4; 787-790
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Search for Dimensionality Crossover of Spin-Glass Freezing in Superlattices of Cd$\text{}_{0.50}$Mn$\text{}_{0.50}$Te/CdTe
Autorzy:
Sawicki, M.
Dietl, T.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Skośkiewicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/1952078.pdf
Data publikacji:
1996-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.-y
75.50.Rr
75.50.Lk
Opis:
SQUID measurements of the time decay of the thermoremanent magnetization (field-cooled in 1000 Oe) at long time scale, 10$\text{}^{2}$ < t < 10$\text{}^{5}$ s, are presented for MBE grown Cd$\text{}_{0.50}$Mn$\text{}_{0.50}$Te. We found that for both thin (32 Å) and thick (2500 Å) layers the spin-glass dynamics is characterized by a similar value of k = -(1/T$\text{}_{f}$)(dT$\text{}_{f}$/dlogt) > 0.05, indicating the absence of the phase transition at nonzero temperature under the experimental conditions.
Źródło:
Acta Physica Polonica A; 1996, 90, 5; 919-922
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Jod i wapń w wodach do picia woj. białostockiego
Iodine and calcium in drinking water in the Białystok province
Autorzy:
Januszko, T.
Karczewski, J.
Poplawska, T.
Smorczewska, B.
Suszczynska-Falecka, Z.
Powiązania:
https://bibliotekanauki.pl/articles/873239.pdf
Data publikacji:
1977
Wydawca:
Narodowy Instytut Zdrowia Publicznego. Państwowy Zakład Higieny
Tematy:
woj.bialostockie
woda pitna
jod
wapn
zawartosc jodu
zawartosc wapnia
badania naukowe
Źródło:
Roczniki Państwowego Zakładu Higieny; 1977, 28, 5
0035-7715
Pojawia się w:
Roczniki Państwowego Zakładu Higieny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrical Properties of p-ZnTe/n-CdTe Photodiodes
Autorzy:
Chusnutdinow, S.
Makhniy, V.
Wojtowicz, T.
Karczewski, G.
Powiązania:
https://bibliotekanauki.pl/articles/1409588.pdf
Data publikacji:
2012-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.15.Hi
73.61.Ga
85.60.Dw
88.40.jm
Opis:
Current-voltage (I-V) and capacitance-voltage (C-V) characteristics of photovoltaic, thinfilm p-ZnTe/n-CdTe heterojunctions have been studied in the temperature range of 280-400 K. The p-n junctions were grown by MBE on (100) semi-insulating GaAs substrates. From the analysis of I-V and C-V curves the potential barrier height of the junctions and its temperature dependence are determined. The relatively large value of the temperature coefficient of the potential barrier height (2.5-3.0 × $10^{-3}$ eV/K) indicates a high density of defects at the p-ZnTe/n-CdTe interface. The presence of interface defects limits the efficiency of the solar energy conversion of these devices.
Źródło:
Acta Physica Polonica A; 2012, 122, 6; 1077-1079
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changing the Properties of the CdTe/ZnTe Quantum Dots by in situ Annealing during the Growth
Autorzy:
Wojnar, P.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/2047681.pdf
Data publikacji:
2007-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.De
78.55.Et
Opis:
We present an attempt to control the properties of CdTe/ZnTe self-assembled quantum dots during their formation in the process of molecular beam epitaxy. Namely, the structures were in situ annealed at various temperatures and annealing times after the formation of quantum dots, before the deposition of a capping layer. Depending on the annealing parameters, the dots exhibit different optical properties which were studied by means of spatially resolved photoluminescence. From the analysis of these results, the information about relative changes of the average size and sheet density of quantum dots was extracted.
Źródło:
Acta Physica Polonica A; 2007, 112, 2; 283-288
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Częstośc występowania wola u dzieci zamieszkałych na wsi a stężenie jodu, wapnia i magnezu w wodach do picia na terenie woj. białostockiego
Chastotnost' pojavlenija zoba u detejj prozhivajushhikh v derevne i koncentracija ioda kal'cija i magnija v pit'evojj vode na territorii belostokskogo voevodstva
Goitre incidence in children living in villages in the Białystok region and the concentrations od iodine, calcium and magnesium in drinking water
Autorzy:
Januszko, T.
Karczewski, J.
Suszczynska-Falecka, Z.
Rybaczuk, M.
Powiązania:
https://bibliotekanauki.pl/articles/872482.pdf
Data publikacji:
1981
Wydawca:
Narodowy Instytut Zdrowia Publicznego. Państwowy Zakład Higieny
Tematy:
choroby czlowieka
dzieci
wole
wies
stezenie jodu
stezenie wapnia
stezenie magnezu
woda
Bialystok
niedobor jodu
zdrowie czlowieka
Źródło:
Roczniki Państwowego Zakładu Higieny; 1981, 32, 1
0035-7715
Pojawia się w:
Roczniki Państwowego Zakładu Higieny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Epitaxial Growths of II-VI Compounds on (110) Substrates
Autorzy:
Cywiński, G.
Wojtowicz, T.
Kopalko, K.
Karczewski, G.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1969044.pdf
Data publikacji:
1998-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.55.-a
Opis:
We studied epitaxial growth conditions of II-VI semiconductors on (110) substrates, which is indispensable for fabrication of T-shaped quantum wire structures. We experimented with different types of (110)-oriented substrates and monitored the surface quality of deposited layers in situ by reflection high energy electron diffraction and ex situ by photoluminescence. The aim of this work is to find optimum growth conditions of II-VI compounds on a cleaved edge of a superlattice as required by the overgrowth method.
Źródło:
Acta Physica Polonica A; 1998, 94, 2; 281-284
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
δ-Doped CdTe/Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te Multiple Quantum Wells Investigated by Photoreflectance Spectroscopy
Autorzy:
Sitarek, P.
Misiewicz, J.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1933972.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.72.Vv
78.66.Hf
Opis:
Room temperature photoreflectance spectroscopy was used to investigate CdTe/Cd$\text{}_{1-x}$Mn$\text{}_{x}$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.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 901-904
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Strain Relaxation of ZnTe/CdTe and CdTe/ZnTe heterostructures: In Situ Study
Autorzy:
Riesz, F.
Kret, S.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1952073.pdf
Data publikacji:
1996-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.14.Hg
68.55.Bd
68.65.+g
Opis:
The strain relaxation kinetics of ZnTe/CdTe and CdTe/ZnTe heterostructures grown on GaAs substrates by molecular beam epitaxy are studied by in situ reflection high-energy electron diffraction. The observed critical layer thickness is 5 monolayers for ZnTe/CdTe and less than 1 monolayer for CdTe/ZnTe. The relaxation is anisotropic. Dislocation core parameters and relaxation rate constants were determined using a kinetic model and assuming strain-dependent activation energy of dislocation movement.
Źródło:
Acta Physica Polonica A; 1996, 90, 5; 911-914
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Photoluminescence of CdTe/CdMgTe Double Quantum Wells with a Two-Dimensional Electron Gas
Autorzy:
Deresz, M.
Wiater, M.
Karczewski, G.
Wojtowicz, T.
Łusakowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1033223.pdf
Data publikacji:
2017-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
CdTe/CdMgTe quantum wells
magnetophotoluminescence
Opis:
Magnetophotoluminescence measurements at liquid helium temperatures were carried out on asymmetric double quantum wells based on CdTe/CdMgTe heterostructures. Due to doping with shallow iodine donors, a two-dimensional electron gas was present in the quantum wells. The samples studied differed with the quantum well widths and doping level. We show a resemblance of the luminescence to results obtained on single quantum wells which suggests that in samples studied the quantum wells are not strongly coupled.
Źródło:
Acta Physica Polonica A; 2017, 132, 2; 390-392
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Search for T-Shaped Quantum Wires in CdTe/CdMg(Mn)Te System
Autorzy:
Cywiński, G.
Wojtowicz, T.
Karczewski, G.
Kossut, J.
Gębicki, W.
Powiązania:
https://bibliotekanauki.pl/articles/1969038.pdf
Data publikacji:
1998-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Rn
73.20.Dx
85.40.Ux
Opis:
We attempted to produce and to investigate T-shaped wire structures of II-VI compounds. Our samples were grown on GaAs hybrid substrates in a two-stage growth process. The photoluminescence measurements resulted into two different possible polarization behaviors of recorder signal. We interpret one of these behaviors as due to quantum wire formation.
Źródło:
Acta Physica Polonica A; 1998, 94, 2; 277-280
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High-Resolution X-Ray Diffraction Studies on MBE-Grown p-ZnTe/n-CdTe Heterojunctions for Solar Cell Applications
Autorzy:
Wichrowska, K.
Domagala, J.
Wosinski, T.
Chusnutdinow, S.
Karczewski, G.
Powiązania:
https://bibliotekanauki.pl/articles/1375736.pdf
Data publikacji:
2014-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.05.cp
81.05.Dz
81.15.Hi
88.40.jm
Opis:
High-resolution X-ray diffractometer was used to study structural quality, lattice parameters and misfit strain in p-ZnTe/n-CdTe heterojunctions grown by the molecular-beam epitaxy technique on two different (001)-oriented substrates of GaAs and CdTe. The X-ray diffractometer results indicate that the CdTe layers, grown on lattice mismatched GaAs substrate, are partially relaxed, by the formation of misfit dislocations at the interface, and display residual vertical strain of the order of $10^{-4}$. The presence of threading dislocations in the layers effectively limits the efficiency of solar energy conversion in the investigated heterojunctions. Homoepitaxially grown CdTe layers, of much better structural quality, display unexpected compressive strain in the layers and the relaxed lattice parameter larger than that of the substrate. Possible reasons for the formation of that unusual strain are discussed.
Źródło:
Acta Physica Polonica A; 2014, 126, 5; 1083-1086
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Deep Electron Traps in CdTe:In Films Grown by Molecular Beam Epitaxy
Autorzy:
Żakrzewski, A. K.
Dobaczewski, L.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1934051.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.55.Ln
73.61.Ga
Opis:
N-type indium doped CdTe grown on n$\text{}^{+}$-GaAs by molecular beam epitaxy has been studied by the standard deep level transient spectroscopy and the isothermal Laplace-transform deep level transient spectroscopy. It was found that the Cd/Te flux ratio strongly influences the deep level transient spectroscopy results. The unusual temperature dependence of the electron emission rate in films grown at nearly stoichiometric conditions may point out that the observed defect is resonant with the conduction band.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 961-964
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of Optical Transitions from CdTe and CdMnTe Quantum Dots Embedded in ZnTe Nanowires
Autorzy:
Szymura, M.
Kłopotowski, Ł.
Wojnar, P.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1399096.pdf
Data publikacji:
2013-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Et
78.67.Uh
78.67.Hc
Opis:
We study photoluminescence properties of CdTe and CdMnTe quantum dots embedded in ZnTe nanowires. The nanowires were grown by molecular beam epitaxy, applying the vapor-liquid-solid growth mechanism. Linear polarization anisotropy measurements allow us to assess that the excitonic transitions originate from a single nanowire. We identify the optical transitions by comparing observed spectroscopic shifts with the universal emission pattern from the epitaxial CdTe dots. We support this identification by analyzing the photoluminescence intensity dependence on excitation power.
Źródło:
Acta Physica Polonica A; 2013, 124, 5; 824-826
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Native Deep-Level Defects in MBE-Grown p-Type CdTe
Autorzy:
Olender, K.
Wosiński, T.
Mąkosa, A.
Dłużewski, P.
Kolkovsky, V.
Karczewski, G.
Powiązania:
https://bibliotekanauki.pl/articles/1492964.pdf
Data publikacji:
2011-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Gs
68.37.Lp
61.72.J-
61.72.Lk
Opis:
Deep-level transient spectroscopy was used to study the defect levels in p-type CdTe layers grown by the molecular-beam epitaxy technique on lattice-mismatched GaAs substrates. In our measurements we have observed five hole traps. Two of the traps, displaying exponential capture kinetics, have been assigned to native point defects, the Cd vacancy and a complex formed of Cd vacancy and Te antisite, produced in the CdTe layers during their growth. The other two traps have been attributed to electronic states of threading dislocations on the ground of their logarithmic capture kinetics. The last trap, which was observed only when the investigated space charge region was close to the metal-semiconductor interface, has been ascribed to surface states.
Źródło:
Acta Physica Polonica A; 2011, 120, 5; 946-949
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical and Electrical Properties, of ZnO-Nanowire/Si-Substrate Junctions Studied by Scanning Probe Microscopy
Autorzy:
Aleszkiewicz, M.
Fronc, K.
Wróbel, J.
Klepka, M.
Wojtowicz, T.
Karczewski, G.
Powiązania:
https://bibliotekanauki.pl/articles/2047440.pdf
Data publikacji:
2007-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.37.Ef
68.37.Ps
68.65.La
73.21.Hb
78.67.Lt
Opis:
Scanning tunneling spectroscopy was used to check the tunneling I-V characteristics of junctions formed by n-ZnO nanowires deposited on Si substrates with n- and p-type electrical conductivity (i.e. n-ZnO nanowire/n-Si and n-ZnO nanowire/p-Si junctions, respectively). Simultaneously, several phenomena which influence the measured I-V spectra were studied by atomic force microscopy. These influencing factors are: the deposition density of the nanowires, the possibility of surface modification by tip movement (difference in attraction forces between nanowires and the p-Si and n-Si) and the aging of the surface.
Źródło:
Acta Physica Polonica A; 2007, 112, 2; 255-260
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Temperature Dependence of Exciton and Trion States in CdTe Quantum Well at High Magnetic Fields
Autorzy:
Andronikov, D.
Platonov, A.
Crooker, S.
Barrick, T.
Karczewski, G.
Kochereshko, V.
Powiązania:
https://bibliotekanauki.pl/articles/2043711.pdf
Data publikacji:
2005-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.Ji
73.21.Fg
78.55.Et
78.67.De
Opis:
Temperature dependent photoluminescence and reflectivity spectra of excitons, singlet and triplet states of trions were studied in CdTe-based quantum wells at high magnetic fields. Interesting features of the exciton and trion spectral lines with altering temperatures are explained by analyzing the thermal population and the kinetics of the exciton-electron-trion energetic system.
Źródło:
Acta Physica Polonica A; 2005, 108, 4; 653-660
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High Mobility 2D Electron Gas in CdTe/CdMgTe Heterostructures
Autorzy:
Karczewski, G.
Jaroszyński, J.
Kutrowski, M.
Barcz, A.
Wojtowicz, T.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1968126.pdf
Data publikacji:
1997-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.40.Hm
Opis:
We report on iodine doping of molecular beam epitaxy (MBE)-grown Cd(Mn)Te quasi-bulk films and modulation-doped CdTe/Cd$\text{}_{1-y}$Mg$\text{}_{y}$Te two-dimensional (2D) single quantum well structures. Modulation doping with iodine of CdTe/Cd$\text{}_{1-y}$Mg$\text{}_{y}$Te structures resulted in fabrication of a 2D electron gas with mobility exceeding 10$\text{}^{5}$ cm$\text{}^{2}$/(V s). This is the highest mobility reported in wide-gap II-VI materials.
Źródło:
Acta Physica Polonica A; 1997, 92, 4; 829-832
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Force Microscopy Study of $Zn_{1-x}Co_{x}O$ Nanowires Grown by Rapid Thermal Evaporation
Autorzy:
Aleszkiewicz, M.
Fronc, K.
Aleszkiewicz, P.
Zaleszczyk, W.
Dziawa, P.
Wojciechowski, T.
Wojtowicz, T.
Karczewski, G.
Powiązania:
https://bibliotekanauki.pl/articles/1791327.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.37.Rt
62.23.Hj
Opis:
In this work we studied domain structure of $Zn_{1-x}Co_{x}O$ nanowires which are single arms of tetrapode crystals. The as-grown material exhibits hysteretic behavior even at room temperature as revealed by SQUID mesurements. In order to get insight into the magnetic properties of individual tetrapodes they were dismembered into nanowires of nanometric diameters, deposited on a flat substrate and imaged by magnetic force microscopy. A magnetic interaction between the magnetic force microscopy probe and single nanowires has been detected which confirms that nanometric volume of the material possesses a magnetic moment. The magnetic force microscopy contrast is attractively independent of the tip magnetization direction which indicates that shape anisotropy of nanowires is not strong enough to prevent occurrence of tip-induced magnetic field disturbance.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 865-867
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recombination Processes in Doped CdTe/CdMnTe Multiple Quantum Well Structures Grown by Molecular Beam Epitaxy
Autorzy:
Godlewski, M.
Wojtowicz, T.
Karczewski, G.
Kossut, J.
Bergman, J. P.
Monemar, B.
Powiązania:
https://bibliotekanauki.pl/articles/1968089.pdf
Data publikacji:
1997-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.47.+p
78.55.Et
Opis:
An influence of doping level on exciton properties in n-doped multiple quantum well structures of CdTe/CdMnTe is studied for multiple quantum well structures prepared in the way that donor (indium) concentration changes within the length of the sample. We show that the formation scenario for neutral donor bound excitons in low-dimensional structures can be different from that observed in bulk samples. We further show that in the case of such quantum well structures we can selectively excite either photoluminescence emission of localized or donor bound excitons, which is a consequence of surprisingly weak energy transfer link between two types of excitonic transitions.
Źródło:
Acta Physica Polonica A; 1997, 92, 4; 757-760
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exciton Dynamics in ZnTe Based Semimagnetic Semiconductors and CdMnTe Quantum Wells
Autorzy:
The Khoi, Nguyen
Gaj, J.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Demianiuk, M.
Powiązania:
https://bibliotekanauki.pl/articles/1952068.pdf
Data publikacji:
1996-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
78.66.Hf
73.20.Dx
Opis:
Inelastic scattering of excitons on LO phonons in ZnTe based bulk semimagnetic semiconductors with low concentration of paramagnetic ions (Mn$\text{}^{2+}$, Fe$\text{}^{2+}$ and Cr$\text{}^{2+}$) was studied. A polarization degree of the LO phonon Raman lines was measured as a function of the exciton splitting in a magnetic field, and allowed us to determine the polarization lifetime (polariton flight time). A similar method was used to investigate multiple Mn$\text{}^{2+}$ spin-flip scattering in CdMnTe quantum well. The cascade model seems to be not adequate to interpret the dependence of the polarization degree on the order of scattering.
Źródło:
Acta Physica Polonica A; 1996, 90, 5; 899-902
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantum Hall Ferromagnet in Magnetically-Doped Quantum Wells
Autorzy:
Andrearczyk, T.
Jaroszyński, J.
Wróbel, J.
Karczewski, G.
Wojtowicz, T.
Papis, E.
Kamińska, E.
Piotrowska, A.
Popović, D.
Dietl, T.
Powiązania:
https://bibliotekanauki.pl/articles/2036881.pdf
Data publikacji:
2003-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.43.Nq
72.25.Dc
73.61.Ga
75.50.Pp
Opis:
The article reviews our recent studies on quantum Hall ferromagnetism in diluted magnetic semiconductors. We carried out magnetoresistance studies on modulation-doped, gated heterostructures of (Cd,Mn)Te/(Cd,Mg)Te:I. We put into evidence the formation of Ising quantum Hall ferromagnet with Curie temperature T$\text{}_{C}$ as high as 2 K. Quantum Hall ferromagnetism is manifested by anomalous magnetoresistance maxima. Moreover, magnitude of these spikes depends dramatically on the history of the sample, shows hysteresis when either magnetic field or gate voltage are swept, stretched-exponential time evolution characteristic of glassy systems, and strong Barkhausen noise. Our study suggests that these metastabilities stem from the slow dynamics of ferromagnetic domains.
Źródło:
Acta Physica Polonica A; 2003, 104, 2; 93-102
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectroscopy of Indirect Excitons in Vertically Stacked CdTe Quantum Dot Structures
Autorzy:
Kukliński, K.
Kłopotowski, Ł.
Fronc, K.
Wojnar, P.
Wojciechowski, T.
Czapkiewicz, M.
Kossut, J.
Karczewski, G.
Wojtowicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/1492851.pdf
Data publikacji:
2011-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Gs
78.67.Hc
32.60.+i
Opis:
We show that by means of an electric field we can tune the energy levels in vertical quantum dot pairs and study transitions related to recombination of direct and indirect excitons. With decreasing the reverse bias, we observe both the blue- and red-shifted indirect exciton transitions. Based on the band profile of our device, we conclude that the former corresponds to the recombination of the electron and hole localized in the top and the bottom dot, respectively and the latter is related to the recombination of the electron and hole localized in the bottom and the top dot, respectively.
Źródło:
Acta Physica Polonica A; 2011, 120, 5; 856-858
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetization Dynamics of a (Cd,Mn)Te Quantum Well in Pulsed Magnetic Field
Autorzy:
Kobak, J.
Goryca, M.
Kossacki, P.
Golnik, A.
Karczewski, G.
Wojtowicz, T.
Gaj, J.
Powiązania:
https://bibliotekanauki.pl/articles/1791344.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
71.70.Gm
78.55.Et
75.75.-c
Opis:
In this paper we present studies of magnetization relaxation in a (Cd,Mn)Te quantum well containing 3.2% of Mn, after a pulse of magnetic field. The relaxation was found to be very fast, with dominant component faster than 10 ns. Upon application of static magnetic field the relaxation does not slow down, in contrast with the behavior of very diluted quantum wells or bulk material.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 907-908
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cold and Hot Excitons in CdMnTe/CdMgTe Quantum Wells in Strong Excitation Regime and External Magnetic Field
Autorzy:
Trajnerowicz, A.
Golnik, A.
Kossacki, P.
Bardyszewski, W.
Wiater, M.
Karczewski, G.
Wojtowicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/1791298.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.De
71.35.Lk
78.47.-p
Opis:
Systematic studies of neutral heavy-hole excitonic line energy changes in a strong excitation regime were carried out by means of a pump-probe method for quantum wells containing a 2D gas of free holes. Energy shift of $X_{e1hh1}$ line was analyzed for different excitation energies at fixed delay between pump and probe pulses, also under external magnetic field. It was observed that this shift depends not only on the density of created excitons but also directly on the pump energy. In co-polarization configuration for excitation energy below an absorption resonance the energetic blue shift rises linearly with the elevated exciton density (localized excitons are created). For energies slightly above the resonance, the blue shift diminishes dramatically in spite of high exciton density present (delocalized excitons are created). Model absorption calculations are in qualitative agreement with the experimental data.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 849-851
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-Ohmic Conductivity of High Resistivity CdTe
Autorzy:
Łusakowski, J.
Szczytkowski, J.
Szadkowski, K.
Kamińska, E.
Piotrowska, A.
Karczewski, G.
Wojtowicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/1933850.pdf
Data publikacji:
1995-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.80.-r
Opis:
Conductivity measurements were carried out at room temperature on samples of nominally undoped Bridgman, bulk crystals and MBE-grown layers of CdTe. The samples were equipped with indium contacts which made it possible to determine the voltage distribution along the path of the current flow. The results show that for both types of CdTe almost all of the applied voltage drops in the vicinity of the positively biased contact. The resistance of the samples was shown not to depend on the distance between the pads. The results agree with predictions of model of current injection into semiconductors with deep traps.
Źródło:
Acta Physica Polonica A; 1995, 88, 4; 803-806
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unusual Time Dependence of Magnetization Relaxation in MBE Grown Epilayer of CdMnTe
Autorzy:
Witowski, A. M.
Moll, H. P.
Wyder, P.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1934049.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.60.Wm
76.30.Fc
Opis:
The temporal behavior of the magnetization due to the spin-lattice relaxation for bulk and MBE grown epilayer of CdMnTe is compared. The time dependence of the epilayer magnetization changes (dM/dt) is nonmonotonic. After the main part, a second structure appears. It can be explained only by the assumption of energy storage and a delayed additional rise of specimen temperature. The nature of the storage is unknown.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 953-956
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical Characterization of MBE-Grown Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te Layers by Raman Spectroscopy
Autorzy:
Szuszkiewicz, W.
Dynowska, E.
Janik, E.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Jouanne, M.
Powiązania:
https://bibliotekanauki.pl/articles/1945228.pdf
Data publikacji:
1996-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
63.20.-e
75.50.Pp
78.30.-j
Opis:
In this paper we discuss a possibility of an optical characterization of thin semiconductor epilayers by Raman scattering measurements. As an example zinc blende Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te epilayers (0.66 ≤ x ≤ 1.0) have been grown by molecular beam epitaxy method and investigated by Raman scattering and X-ray diffraction. Information resulting from both methods is compared and discussed.
Źródło:
Acta Physica Polonica A; 1996, 89, 3; 335-340
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exciton Magneto-Optical Study on Single Quantum Wells, Cd$\text{}_{1-x}$Zn$\text{}_{x}$Te/Cd$\text{}_{1-x'-y}$Zn$\text{}_{x}$'Mn$\text{}_{y}$Te
Autorzy:
Takeyama, S.
Grabecki, G.
Adachi, S.
Takagi, Y.
Wojtowicz, T.
Karczewski, G.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1934045.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.-m
78.20.Ls
78.66.Hf
Opis:
Four-single quantum wells composed of the ternary non-magnetic compounds Cd$\text{}_{0.93}$Zn$\text{}_{0.07}$Te (well width = 13, 19, 40, 90 Å), separated by the quaternary magnetic-compound Cd$\text{}_{0.48}$Zn$\text{}_{0.04}$Mn$\text{}_{0.48}$Te on (100)GaAs substrate were grown by MBE, and exhibited clear and distinctive photoluminescence lines corresponding to each quantum well. Double luminescence peaks with closely spaced within one well were observed from 90 Å and 40 Å quantum wells. Temperature and magnetic-field study revealed characteristic luminescence features associated with a bound exciton near the interface rather than with one monolayer fluctuation.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 945-948
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Excitons and Trions in Modulation Doped Structures in High Magnetic Fields
Autorzy:
Kochereshko, V.
Andronikov, D.
Platonov, A.
Crooker, S.
Barrick, T.
Karczewski, G.
Tronc, P.
Powiązania:
https://bibliotekanauki.pl/articles/2038321.pdf
Data publikacji:
2004-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Et
71.35.-y
78.20.Ls
78.40.Fy
Opis:
Photoluminescence spectra of modulation-doped CdTe/CdMgTe quantum well structures containing two-dimensional electron gases of low, moderate and high electron concentrations were studied in high magnetic fields up to 45 T. The recombination line of triplet trion state was found in the spectra. A model calculation of photoluminescence spectra in magnetic fields, which takes into account singlet and triplet trion states, was carried out. It was shown that the dark triplet becomes observable in photoluminescence spectra because it becomes the only recombination channel when the formation of the singlet trion state is suppressed by magnetic fields.
Źródło:
Acta Physica Polonica A; 2004, 106, 3; 319-328
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Interface-Induced Disorder on Classical and Quantum Conductivity of CdTe:IN Epitaxial Layers
Autorzy:
Łusakowski, J.
Karpierz, K.
Grynberg, M.
Karczewski, G.
Wojtowicz, T.
Contreras, S.
Callen, O.
Powiązania:
https://bibliotekanauki.pl/articles/1968369.pdf
Data publikacji:
1997-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.50.Jt
73.61.Ga
Opis:
An influence of disorder originated from the substratelayer interface on electrical properties of CdTe:In layers was investigated by means of the Hall effect and magnetoresistance measurements at low temperatures. An estimation of a scattering rate due to interface-induced disorder is given. Characteristic features of a magnetic field dependence of magnetoresistance are explained by an influence of quantum interference of scattered electron waves both in the hopping and the free electron conductivity regimes.
Źródło:
Acta Physica Polonica A; 1997, 92, 5; 911-914
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Excitonic Energy Shifts in CdMnTe/CdMgTe Quantum Wells under Resonant Excitation in Presence of 2D Carrier Gas
Autorzy:
Trajnerowicz, A.
Golnik, A.
Kossacki, P.
Bardyszewski, W.
Wiater, M.
Karczewski, G.
Wojtowicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/1811999.pdf
Data publikacji:
2008-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.De
71.35.Lk
78.47.-p
Opis:
Systematic studies of amplitude and energy changes of excitonic lines in a strong excitation regime were carried out by a pump-probe method. The series of samples containing quantum wells with well width from 80 Åto 140 Åwas investigated. One 80 Åsample was n-doped with iodine, the rest of the quantum wells were intentionally undoped but contained a 2D gas of free holes. Its density could be varied by changing an intensity of additional illumination. The resonant creation of high population of e1hh1 excitons causes the energetic blue shift of the same due to interactions between excitons. The blue shifts did not depend on the concentration of 2D gas of carriers whereas it did depend on the power of excitation beam. Model calculations of absorption show qualitative agreement with the experimental data.
Źródło:
Acta Physica Polonica A; 2008, 114, 5; 1403-1409
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conductance Fluctuations in Quantum Wires of n-CdTe and n-Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te
Autorzy:
Jaroszyński, J.
Wróbel, J.
Sawicki, M.
Skośkiewicz, T.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Dietl, T.
Kamińska, E.
Papis, E.
Barcz, A.
Piotrowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/1934061.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Rn
73.61.Ga
73.20.Fz
Opis:
We present millikelvin studies of magnetoconductance in submicron wires of In-doped n$\text{}^{+}$-CdTe and n$\text{}^{+}$-Cd$\text{}_{0.99}$Mn$\text{}_{0.01}$Te epilayers. Weak-field magnetoresistance which arises from quantum localization as well as universal conductance fluctuations have been observed. The exchange coupling to magnetic impurities is shown to decrease the correlation field of the fluctuations. This novel effect is interpreted by invoking a new driving mechanism of the magnetoconductance fluctuations - the redistribution of the electrons between energy levels of the system, induced by the giant s-d spin-splitting of the electronic states.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 1000-1004
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exciton Magnetic Polaron Features in Photoluminescence Excitation Spectra of CdTe/(CdMn)Te Quantum Wells with High Mn Contents
Autorzy:
Mackh, G.
Ossau, W.
Yakovlev, D. R.
Landwehr, G.
Wojtowicz, T.
Karczewski, G.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1933923.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.+z
78.55.Et
Opis:
Exciton magnetic polarons are studied in CdTe/Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te (0.4 ≤ x ≤ 0.8) quantum wells. The magnetic polaron formation leads to the appearance of an additional line in the photoluminescence excitation spectra, which can be employed to determine the Zeeman splittings more exactly than by using the free exciton peak. We find an overall increase in the polaron energy with increasing x in the whole range of Mn contents studied.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 849-852
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MBE Growth and Characterization of Cubic MnTe(111) on BaF$\text{}_{2}$ Substrates
Autorzy:
Janik, E.
Wojtowicz, T.
Dynowska, E.
Bąk-Misiuk, J.
Domagała, J.
Karczewski, G.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1934056.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
68.55.Bd
68.55.Jk
Opis:
We report on growth by molecular beam epitaxy of cubic MnTe(111) layers on BaF$\text{}_{2}$ (111) substrates. Layers as thick as 0.2-1.0 μm were grown. Basic characterization by X-ray diffraction shows that the cubic crystal structure is deformed to orthorhombic symmetry.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 982-984
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Optical Properties of CdTe/CdMnTe Quantum Wells Grown by Molecular Beam and Atomic Layer Epitaxy
Autorzy:
Godlewski, M.
Kopalko, K.
Wojtowicz, T.
Karczewski, G.
Kossut, J.
Bergman, J. P.
Monemar, B.
Powiązania:
https://bibliotekanauki.pl/articles/1952470.pdf
Data publikacji:
1996-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.+z
78.47.+p
78.55.Et
Opis:
Optical properties of a series of CdTe/CdMnTe multi quantum well structures grown with MBE and ALE (CdTe quantum wells only) methods are compared. Based on the results of the photoluminescence experiments we conclude that the ALE growth leads to a different lateral scale of quantum well width fluctuations, which results in different exciton properties in two multi quantum well systems studied. In the wells grown with ALE method excitons are less localized. They can migrate in a quantum well plane between quantum well regions varying in thickness by 1 monolayer.
Źródło:
Acta Physica Polonica A; 1996, 90, 5; 1012-1016
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization and Selected Physical Properties of CdTe/MnTe Short Period Strained Superlattices
Autorzy:
Szuszkiewicz, W.
Dynowska, E.
Bąk-Misiuk, J.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Jouanne, M.
Powiązania:
https://bibliotekanauki.pl/articles/1952708.pdf
Data publikacji:
1996-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
63.20.-e
78.30.Fs
Opis:
Phonon excitations in (CdTe)$\text{}_{12}$/(MnTe)$\text{}_{n}$ (100) superlattices (n=2, 4, 8) were investigated at 295 K and 25 K with the use of Raman scattering. From the "folded" phonon frequencies the elastic constant c$\text{}_{11}$ value for MnTe was estimated. The strain arising from lattice mismatch (determined by X-ray diffraction) results in shifts of MnTe and CdTe "confined" LO phonon frequencies. For the precise determination of LO phonon dispersions an additional shift due to Mn diffusion at the CdTe/MnTe interface should be taken into account.
Źródło:
Acta Physica Polonica A; 1996, 90, 5; 1090-1094
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exciton Properties in CdTe/CdMnTe Quantum Well Structures with Strong Localization Effects
Autorzy:
Godlewski, M.
Narkowicz, R.
Wojtowicz, T.
Karczewski, G.
Kossut, J.
Bergman, J. P.
Monemar, B.
Powiązania:
https://bibliotekanauki.pl/articles/1969075.pdf
Data publikacji:
1998-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.-y
71.55.Jv
73.20.Mf
Opis:
Strong localization effects present in quantum well structures of CdTe/ CdMnTe noticeably affect exciton dynamics and strength and character of exciton-phonon interaction. We show that the temperature dependences of the PL linewidth, PL peak wavelength and PL decay time strongly deviate from those expected for Wannier-excitons in structures with atomically smooth interfaces.
Źródło:
Acta Physica Polonica A; 1998, 94, 2; 317-320
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reduction of the Optical Losses in CdTe/ZnTe Thin-Film Solar Cells
Autorzy:
Chusnutdinow, S.
Pietruszka, R.
Zaleszczyk, W.
Makhniy, V.
Wiater, M.
Kolkovsky, V.
Wojtowicz, T.
Karczewski, G.
Powiązania:
https://bibliotekanauki.pl/articles/1375701.pdf
Data publikacji:
2014-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.15.Hi
73.61.Ga
85.60.Dw
88.40.jm
Opis:
We report on reduction of optical losses in n-CdTe/p-ZnTe thin-film solar cells grown by molecular beam epitaxy. The investigated thin-film devices were grown from elemental sources on monocrystalline, semi-insulating, (100)-oriented GaAs substrates. The optical losses have been reduced by a texturing of the device surface and by depositing of a ZnO antireflection coating. Current-voltage and spectral characteristics of the investigated p-ZnTe/n-CdTe solar cells depend significantly on the preparation of the surface of the ZnTe window. We describe a procedure of chemical etching of the ZnTe window leading to surface texturing. A ZnO layer of proper thickness deposited by low-temperature atomic layer deposition technique on the ZnTe surface forms an effective antireflection coating that leads to the reduction of optical losses. Due to reduction of the optical losses we observe increase of the short-circuit current, $J_{SC}$, by almost 60% and of the energy conversion efficiency by 44%.
Źródło:
Acta Physica Polonica A; 2014, 126, 5; 1072-1075
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Single-Photon Emission from a Highly Excited CdTe Quantum Dot
Autorzy:
Nowak, S.
Goryca, M.
Kazimierczuk, T.
Gaj, J.
Golnik, A.
Kossacki, P.
Wojnar, P.
Karczewski, G.
Powiązania:
https://bibliotekanauki.pl/articles/1811969.pdf
Data publikacji:
2008-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.21.La
78.55.Et
78.67.-n
78.47.-p
Opis:
Time-resolved correlation measurements were performed to examine the statistics of photon emission from a single quantum dot at high excitation levels. The range of strong powers was determined by the saturation of intensity of excitonic lines. The significant contribution of pulsed background luminescence forced us to sophisticated analysis of the photoluminescence spectra. For quantum dots grown in the Stranski-Krastanov mode, one-photon emission was found to a good approximation. Fluctuation type quantum dots exhibit a significant level of multiphoton emission.
Źródło:
Acta Physica Polonica A; 2008, 114, 5; 1273-1278
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Characterization of Molecular Beam Epitaxy Grown $Cd_{1-x}$Mn$\text{}_{x}$Te Structures
Autorzy:
Sawicki, M.
Kolesnik, S.
Wojtowicz, T.
Karczewski, G.
Janik, E.
Kutrowski, M.
Żakrzewski, A.
Dynowska, E.
Dietl, T.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1931934.pdf
Data publikacji:
1995-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.-y
75.50.Rr
75.50.Ee
Opis:
The paper reports on the application of SQUID magnetometry to probe magnetic ion distribution in epilayers and at interfaces of diluted magnetic semiconductors. We present also new results on the possible influence of the magnetic confinement on the formation of the spin-glass phase, and on antiferromagnetic phase transition in zinc-blende MnTe.
Źródło:
Acta Physica Polonica A; 1995, 87, 1; 169-172
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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