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Wyszukujesz frazę "Godlewski, J." wg kryterium: Autor


Tytuł:
Space Charge Limited Currents in Anthracene Crystals under Modulated Illumination
Autorzy:
Uzarczyk, A.
Godlewski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1933388.pdf
Data publikacji:
1995-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.40.+w
Opis:
Space charge limited currents have been examined in anthracene crystals illuminated with a chopped beam of monochromatic light (λ = 420 nm). The beam was uniformly absorbed in the anthracene crystal. The primary objective of our research was to determine mechanisms responsible for the release and trapping of charge carriers in the case of space charge limited currents as a function of time. The experimental results concern the dependences of photocurrents on the frequency of light chopping, light intensity, voltage and current decay after illumination. Photocurrent decay as a function of time was exponential for short time periods (i.e. for milliseconds), while for longer periods it was described by the power function t$\text{}^{-1/l}$, where parameter 1 is the characteristic parameter of the exponential distribution of traps.
Źródło:
Acta Physica Polonica A; 1995, 87, 4-5; 849-854
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An analysis of solar energy conversion systems based on photon and thermal processes
Autorzy:
Fieducik, J.
Godlewski, J.
Powiązania:
https://bibliotekanauki.pl/articles/184520.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
energy conversion
photoelectric effect
thermoelectric process
thermionic emission process
Opis:
Solar spectral irradiance covers a fairly broad wavelength range. Solar radiation is part of the electromagnetic spectrum which is described by the concept of wave-particle duality. The corpuscular theory of electromagnetic radiation states that energy is transmitted by photons. Photons carry specific amounts of energy which can be used to convert solar energy into other types of energy, in particular electricity. The internal photoelectric effect is important for the conversion of solar energy to electricity because the efficiency of the external photoelectric effect is too low. Every quantum of solar energy also carries a certain amount of energy which can be converted into heat energy. The objective of the paper is to analyze and compare the efficiency of solar energy conversion in photon and thermal processes, to review the technological advances made in this field, and to indicate potential directions for the development of systems converting solar energy to electricity.
Źródło:
Geology, Geophysics and Environment; 2016, 42, 4; 403-409
2299-8004
2353-0790
Pojawia się w:
Geology, Geophysics and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The distribution and chemical coding of urinary bladder trigone-projecting neurons in testicular and aorticorenal ganglia in male pigs
Autorzy:
Pidsudko, Z.
Godlewski, J.
Wąsowicz, K.
Powiązania:
https://bibliotekanauki.pl/articles/16539341.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
prevertebral ganglia
urinary bladder trigone
immunohistochemistry
retrograde tracing
neuropeptides
male pig
Opis:
Combined retrograde tracing and double-labelling immunofluorescence were used to investigate the distribution and chemical coding of neurons in testicular (TG) and aorticoerenal (ARG) ganglia supplying the urinary bladder trigone (UBT) in juvenile male pigs (n=4, 12 kg. of body weight). Retrograde fluorescent tracer Fast Blue (FB) was injected into the wall of the bladder trigone under pentobarbital anesthesia. After three weeks all the pigs were deeply anesthetized and transcardially perfused with 4% buffered paraformaldehyde. TG and ARG, were collected and processed for double-labelling immunofluorescence. The expression of tyrosine hydroxylase (TH) or dopamine beta-hydroxylase (DBH), neuropeptide Y (NPY), somatostatin (SOM), galanin (GAL), nitric oxide synthase (NOS) and vesicular acetylcholine transporter (VAChT) were investigated. The cryostat sections were examined with a Zeiss LSM 710 confocal microscope equipped with adequate filter blocks. The TG and ARG were found to contain many FB-positive neurons projecting to the UBT (UBT-PN). The UBT-PN were distributed in both TG and ARG. The majority of them were found in the right ganglia, mostly in TG. Immunohistochemistry disclosed that the vast majority of UBT-PN were noradrenergic (TH- and/or DBH-positive). Many noradrenergic neurons contained also immunoreactivity to NPY, SOM or GAL. Most of the UBT-PN were supplied with VAChT-, or NOS- IR (immunoreactive) varicose nerve fibres. This study has revealed a relatively large population of differently coded prevertebral neurons projecting to the porcine urinary bladder. As judged from their neurochemical organization these nerve cells constitute an important element of the complex neuro-endocrine system involved in the regulation of the porcine urogenital organ function.
Źródło:
Polish Journal of Veterinary Sciences; 2022, 25, 3; 483-487
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electric Current Flow through Tetracene Layer-Anthracene Crystal Junction
Autorzy:
Signerski, R.
Godlewski, J.
Sodolski, H.
Powiązania:
https://bibliotekanauki.pl/articles/1933385.pdf
Data publikacji:
1995-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.40.+w
Opis:
Theoretical and experimental analysis was carried out on electric currents limited by the potential barrier governing the flow of holes from the tetracene layer to the anthracene crystal. Theoretical spatial distributions of charge carriers near the barrier were determined, as well as current-field dependences for the currents flowing through the investigated junction in the presence and in the absence of illumination. A current-field characteristic of the junction conditioned current is described by dependence of the j ∝ E$\text{}_{0}^{3}$ type in the presence of illumination and by the j ∝ E$\text{}_{0}^{2l+1}$ type in the lack of illumination, where l is the characteristic parameter of the trap distribution. Experimental research of the hole currents flowing through the polycrystalline tetracene layer-anthracene monocrystal junction confirmed the theoretical predictions about the current-field characteristics. A remarkably unequivocal confirmation was obtained for the current-field dependences in the presence of illumination.
Źródło:
Acta Physica Polonica A; 1995, 87, 4-5; 843-847
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Analysis of Photoenhanced Electric Currents in Molecular Materials
Autorzy:
Jarosz, G.
Signerski, R.
Godlewski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1933390.pdf
Data publikacji:
1995-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.40.+w
Opis:
This paper presents numerical calculations of photoenhanced current-applied voltage and photoenhanced current-light intensity characteristics with regard to the exciton diffusion length, lifetime of excitons and rate of exciton surface quenching. Dependencies of this type cannot be obtained analytically. It is shown that the increase in diffusion length causes the decrease in current in the case of strong surface quenching of excitons. Simultaneously, it is shown that the quality of crystals influences the photoenhanced current. A better quality of crystals causes the increase in the current in the case of weak surface quenching of excitons.
Źródło:
Acta Physica Polonica A; 1995, 87, 4-5; 855-860
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Struktury fotowoltaiczne z planarnym heterozłączem półprzewodnik II-VI / półprzewodnik molekularny
Photovoltaic Devices Based on Planar II-VI Semiconductor / Molecular Semiconductor Heterojunction
Autorzy:
Signerski, R.
Jarosz, G.
Szostak, J.
Godlewski, J.
Powiązania:
https://bibliotekanauki.pl/articles/159630.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Elektrotechniki
Tematy:
efekt fotowoltaiczny
ogniwa hybrydowe
photovoltaic effect
hybrid solar cells
Opis:
Artykuł przedstawia wybrane wyniki badań własnych nad układami hybrydowymi zbudowanymi na bazie złącza półprzewodnik nieorganiczny II-VI / półprzewodnik organiczny. Na podstawie analizy położenia pasm energetycznych warstw wchodzących w skład wytworzonych ogniw oraz charakterystyk spektralnych prądu zwarcia tych urządzeń, określone zostały procesy prowadzące do fotogeneracji nośników ładunku w badanych układach. W ogniwach zbudowanych na bazie złącz CdS/ZnPc oraz ZnTe/F16ZnPc zaobserwowano zarówno generację bezpośrednią w półprzewodniku nieorganicznym (przejście pasmo-pasmo), jak i generację wynikającą z dysocjacji ekscytonów wzbudzonych w półprzewodniku molekularnym, zachodzącą na złączu obydwu półprzewodników. W przypadku układów zbudowanych na bazie złącza CdTe/DIP, zaobserwowano jedynie fotogenerację drugiego typu.
This article presents chosen results of research on hybrid solar cells based on inorganic II-VI semiconductor/molecular semiconductor heterojunctions. On the basis of energetic structure of fabricated devices and short-circuit current spectral response measured for these cells possible processes leading to photogeneration of free charge carriers were determined. For the cells based on CdS/ZnPc and ZnTe/F16ZnPc heterojunctions two processes were identified: direct photogeneretaion in inorganic semiconductors via band-to-band transitions and dissociation of excitons generated in molecular semiconductors that takes place at the interface of both semiconductors forming the junction. In contrast, only the latter process was observed in case of devices with CdTe/DIP heterojunction.
Źródło:
Prace Instytutu Elektrotechniki; 2014, 264; 91-98
0032-6216
Pojawia się w:
Prace Instytutu Elektrotechniki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Charge Carrier Generation Caused by X-Rays in Organometallic Materials
Autorzy:
Godlewski, J.
Signerski, R.
Jarosz, G.
Stizza, S.
Berrettoni, M.
Powiązania:
https://bibliotekanauki.pl/articles/2011031.pdf
Data publikacji:
1999-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.40.+w
Opis:
Organometallic compounds play an exceptional role among organic compounds. Due to their structure a number of these compounds demonstrate interesting properties in various phenomena. Organometallic compounds show special properties in the case of X-ray absorption owing to considerable differences between the absorption coefficients of metals and light elements. The analysis of processes of charge carrier generation as a result of X-ray absorption in chosen organometallic compounds is the subject of this paper. Spectral dependences of charge carrier photogeneration efficiency around the Cu K-edge in copper phthalocyanine and copper acetylacetoniane have been specially considered. It has been observed that the photocurrent spectrum in these materials follows the absorption spectrum but mutual relation is not directly proportional. Experimental results connected with current-voltage and current-intensity characteristics have been analysed, as well. The obtained relationships have been compared with adequate results connected with charge carrier photogeneration in visible area and UV in organic materials. It has been observed that the X-ray photogeneration of charge carriers in the examined range of energy differs from the mechanisms of charge carrier generation in visible area and UV. The basic differences arise from the participation of secondary electrons, which are generated due to Auger electrons, Compton effect, and metal fluorescence. The process of charge carrier generation as a result of X-rays absorption is characterized by strong recombination of charge carriers in channels in which charge carriers are generated by high energetic secondary electrons.
Źródło:
Acta Physica Polonica A; 1999, 96, 2; 295-301
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Jedno- i dwuwarstwowe organiczne ogniwa fotowoltaiczne
Single and Double-Layer Organic Solar Cells
Autorzy:
Godlewski, J.
Signerski, R.
Jarosz, G.
Obarowska, M.
Szostak, J.
Powiązania:
https://bibliotekanauki.pl/articles/160223.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Elektrotechniki
Tematy:
fotowoltaika
materiały organiczne
photovoltaics
organic materials
Opis:
Omówiona została zasada działania organicznych ogniw fotowoltaicznych na przykładzie ogniw jedno- i dwuwarstwowych. Przedstawione zostały procesy prowadzące do fotogeneracji swobodnych nośników ładunku w układach organicznych, ze szczególnym uwzględnieniem procesu dyfuzji oraz dysocjacji ekscytonu na złączu dwóch materiałów. Przytoczone zostały podstawowe wyrażenia na wartość napięcia fotowoltaicznego dla układów jedno- i dwuwarstwowych oraz wybrane wyniki badań własnych dla ogniw dwuwarstwowych.
This article explains operational principles of organic solar cells for one-layer and bilayer planar devices. A short description of processes leading to photogeneration of free charge carriers, with special emphasis on exciton diffusion to a junction of two materials followed by exciton dissociation at this junction is given. Basic equations for photovoltage obtained for one- and bilayer devices are presented. Moreover, chosen results of research run by our group for bilayer planar solar cells are shown.
Źródło:
Prace Instytutu Elektrotechniki; 2014, 264; 81-90
0032-6216
Pojawia się w:
Prace Instytutu Elektrotechniki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kontrola jakości zbiorników ciśnieniowych z wykorzystaniem systemu wideo-ultradźwiękowego
The quality control of pressure vessels with the use of ultrasound video system
Autorzy:
Jaroszewicz, J.
Godlewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/270959.pdf
Data publikacji:
2012
Wydawca:
Centralny Ośrodek Badawczo-Rozwojowy Aparatury Badawczej i Dydaktycznej, COBRABiD
Tematy:
zbiornik ciśnieniowy
korozja
badanie techniczne
wideo-ultradźwięki
kontrola
czynna grubość płaszcza
ultrasound video system
pressure vessel
quality control
corrosion
tests
Opis:
W niniejszej pracy zaprezentowano metodę wideo-ultradźwiękową do kontroli jakości zbiornika ciśnieniowego, "Chemar" Kielce S.A. JCG16930L, pracującego jako odgazowywacz 2QS w Elektrociepłowni Białystok S.A. /EC/, narażonego na korozję wżerową. Z doświadczeń eksploatacyjnych wynika, że w 19-letniej praktyce eksploatacyjnej odgazowywacza w EC występowały, niewykrywalne dotychczas stosowanymi metodami pomiarowymi, przypadki korozji elektrochemicznej na jego poszyciu. W artykule przedstawiono aktualnie stosowane metody badań jakości odgazowywacza wg. zaleceń Urzędu Dozoru Technicznego oraz wykazano zalety zaproponowanej metody, w szczególności: większe prawdopodobieństwo wykrycia korozji mikrowżerowej bez wyłączania zbiornika z ruchu. Dokonano analizy SWOT proponowanej metody.
In this paper the application of video-quality ultrasonic inspection method of the pressurvise of vessel, "Chemar" Kielce S.A. JCG16930L, functioning as a degasser the 2QS in CHP Białystok S.A., exposed to pitting corrosion has been presented. The operation experience shows that, in 19 years of usage of degasser there have been cases of degasser electrochemical corrosion of the hull, which the current method of measurement has not been able to detect. We present the currently used methods of quality testing desecrator based on the recommendations of the Office of Technical Inspection, and propose method, showing its advantages, in particularly: bigger probability of finding of micro corrosion places without stopped exploitation of the degasser. SWOT of the proposed method analysis has been conducted.
Źródło:
Aparatura Badawcza i Dydaktyczna; 2012, 17, 1; 27-34
2392-1765
Pojawia się w:
Aparatura Badawcza i Dydaktyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zwiększenie współczynnika stateczności globalnej skarpy wysokiego nasypu poprzez wzmocnienie podłoża sztywnymi kolumnami betonowymi CMC/TM
Increase global stability of high embankments by soil reinforcement by application of CMC/TM concrete columns
Autorzy:
Godlewski, T.
Fudali, J.
Saloni, J.
Powiązania:
https://bibliotekanauki.pl/articles/349242.pdf
Data publikacji:
2008
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
kolumna CMC/TM
współczynnik stateczności globalnej
wzmocnienie podłoża
CMC/TM column
global factor of safety
soil reinforcement
Opis:
Przedmiotem artykułu jest zastosowanie wzmocnienia podłoża metodą kolumn CMC/TM w celu zwiększenia stateczności globalnej wysokich nasypów. W artykule opisano technologię wzmacniania podłoża za pomocą kolumn betonowych typu CMC/TM. Scharakteryzowano warunki gruntowe, w których zastosowanie kolumn CMC/TM ma szczególne uzasadnienie techniczne. Przedstawiono podstawowe założenie dotyczące projektowania, mając na uwadze przede wszystkim poprawienie współczynnika stateczności globalnej podłoża. Pokazano przykład poprawnego zastosowania technologii CMC/TM, w którym dzięki zaprojektowaniu odpowiedniego rozstawu kolumn, technologii wykonania i zbrojeniu podstawy nasypu spełniono stan graniczny stateczności globalnej wysokiej budowli ziemnej.
Soil reinforcement by application of CMC/TM columns to increase global stability of high embankments is the subject of this article. The technology of reinforcement by CMC/TM is described. Soil conditions in which the column are justified can be applied are characterized. Basis design assumptions which leads to improvement of global factor of safety are presented. Proper design of column spacing, technology of execution that satisfied the EQU limit state for the subbase of embankment is show on example.
Źródło:
Górnictwo i Geoinżynieria; 2008, 32, 2; 125-137
1732-6702
Pojawia się w:
Górnictwo i Geoinżynieria
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
O pracach nad nową mapą przemarzania gruntu w Polsce
About works on a new map of soil freezing depth in Poland
Autorzy:
Zuranski, J.A.
Godlewski, T.
Wereski, S.
Powiązania:
https://bibliotekanauki.pl/articles/40267.pdf
Data publikacji:
2017
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
grunty
przemarzanie
glebokosc przemarzania
temperatura gruntu
rozklad prawdopodobienstwa
glebokosc izotermy zerowej
okres powrotu
soil
frost penetration
frost penetration depth
ground temperature
probability distribution
zero isotherm
Źródło:
Acta Scientiarum Polonorum. Architectura; 2017, 16, 3
1644-0633
Pojawia się w:
Acta Scientiarum Polonorum. Architectura
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of Synthesis Pressure on Properties of Eu-Doped ZnO Nanopowders Prepared by Microwave Hydrothermal Method
Autorzy:
Rosowska, J.
Kaszewski, J.
Witkowski, B.
Wachnicki, Ł.
Godlewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1185714.pdf
Data publikacji:
2016-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Hx
81.07.Wx
81.20.Ka
78.60.Hk
Opis:
In the current research, europium doped ZnO nanopowders prepared by a microwave hydrothermal method are investigated. The effects of synthesis pressure on the morphologies, crystal structures, and optical properties of Eu-doped ZnO were analyzed by scanning electron microscopy, X-ray diffraction, cathodo- and photoluminescence. From our investigations it can be concluded that the synthesis pressure strongly influences the surface morphology. With the increase of the synthesis pressure from 2 MPa to 10 MPa significant changes can be observed. An increase of the mean crystallites sizes and change of the intensity ratio between the near band edge and defect related deep level emission band of ZnO were observed.
Źródło:
Acta Physica Polonica A; 2016, 130, 5; 1205-1208
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Photo-ESR Studies of Ni doped ZnS and ZnSe
Autorzy:
Surma, M.
Zakrzewski, A. J.
Godlewski, M.
Surkova, T. P.
Powiązania:
https://bibliotekanauki.pl/articles/1932084.pdf
Data publikacji:
1995-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Gs
76.30.He
78.55.Et
Opis:
The results of electron spin resonance experiments are presented for nickel doped ZnS and ZnSe. Energy level position of Ni$\text{}^{1+}$ state in band gap of ZnS and ZnSe is determined. The nonradiative recombination processes of donor-acceptor pairs in Ni doped samples are discussed.
Źródło:
Acta Physica Polonica A; 1995, 87, 1; 221-224
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of phytoestrogen intake in the diet on lipid and sex hormone metabolism in menopausal women, and increased risk of breast cancer
Autorzy:
Kostrzewa-Tarnowska, A.
Czlapka-Matyasik, M.
Walkowiak, J.
Godlewski, D.
Powiązania:
https://bibliotekanauki.pl/articles/3279.pdf
Data publikacji:
2015
Wydawca:
Instytut Medycyny Wsi
Tematy:
phytoestrogen
intake
nutritional habit
diet
lipid
sex hormone
human metabolism
menopausal woman
woman
cancer risk
breast cancer
Opis:
Introduction and objective. Phytoestrogens are one of nutritional factors exhibiting a chemoprotective action, potentially reducing vasomotor symptoms as well as cancerous lesions. The study was ocused on an association between the consumption of phytoestrogens in the diet, blood serum cholesterol concentration and urinary estrogen metabolites levels. Materials and methods. The study was conducted on 55 women in the perimenopausal period, who were characterized by an increased risk of hormone-dependent cancer. Energy and nutritive value of food rations, and especially the level of phytoestrogen consumption in the diets in the examined population, were analyzed using the Wikt Pro computer programme. Estrogen metabolites (2OHE, 16α-OHE1) were determined from 24‑urine samples by the ELISA method. The EMR index was calculated. Plasma total cholesterol concentrations was measured. Results and conclusions. The population with a higher consumption of phytoestrogens and dietary fibre in the diet, at the simultaneous slight limitation of energy value of the food ration, is characterized by an improved blood serum cholesterol concentration and an appropriate estrogen metabolism towards a significant increase in the estrogen index for the cancer lesions in the mammary glands.
Źródło:
Journal of Pre-Clinical and Clinical Research; 2015, 09, 2
1898-2395
Pojawia się w:
Journal of Pre-Clinical and Clinical Research
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:
Effect of Annealing on the Crystal Structure and Microstructure of Pr Doped $ZrO_{2}-Y_{2}O_{3}$ Nanocrystals
Autorzy:
Werner-Malento, E.
Paszkowicz, W.
Fidelus, J.
Godlewski, M.
Yatsunenko, S.
Powiązania:
https://bibliotekanauki.pl/articles/1550117.pdf
Data publikacji:
2010-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.46.-w
61.66.Fn
81.40.-z
Opis:
Rare-earth doped nanocrystalline yttria-stabilized zirconia (YSZ, $ZrO_{2}-Y_{2}O_{3}$) is, recently, a subject of studies because of its luminescent properties. The luminescence may be strongly influenced by the crystal structure and microstructure of the material. In this work, the X-ray diffraction study for Pr doped YSZ nanocrystals is presented. The phase composition dependence on the $Y_{2}O_{3}$ content and on heat treatment conditions is quantitatively determined using the Rietveld method and the similarities and differences between the present data for doped samples and earlier reported data for undoped material are discussed. A formation of high symmetry phases (cubic and tetragonal) is observed for high yttria content in agreement with general tendencies observed in literature for undoped samples.
Źródło:
Acta Physica Polonica A; 2010, 117, 1; 91-97
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Growth Conditions on Optical Properties of ZnCdSe/ZnSe Quantum Wells Grown by Molecular Beam Epitaxy
Autorzy:
Godlewski, M.
Bergman, J. P.
Monemar, B.
Kurtz, E.
Hommel, D.
Powiązania:
https://bibliotekanauki.pl/articles/1950749.pdf
Data publikacji:
1996-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.60.-p
71.35.+z
76.70.Hb
Opis:
The results of investigations of photoluminescence, time-resolved photoluminescence, photoluminescence kinetics and their temperature dependencies are discussed for two types of ZnCdSe/ZnSe multi quantum well structures - for pseudomorphic and for strain relaxed structure. Densities of 2D localized states and averaged localization energies, as seen by excitons, are determined from the photoluminescence kinetics measurements. We show distinct differences between exciton properties in two multi quantum well structures studied.
Źródło:
Acta Physica Polonica A; 1996, 90, 4; 785-788
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical Properties of GaN Epilayers grown by Gas Source Molecular Beam Epitaxy on AlN Buffer Layer on (111) Si
Autorzy:
Godlewski, M.
Bergman, J. P.
Monemar, B.
Rossner, U.
Barski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1950766.pdf
Data publikacji:
1996-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Eq
71.35.+z
78.47.+p
Opis:
Optical properties of GaN/AlN/Si (111) epilayers grown by MBE are studied. The observed decay transients of excitonic emissions and their temperature dependence is explained by an efficient transfer link between bound and free excitons.
Źródło:
Acta Physica Polonica A; 1996, 90, 4; 789-792
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Excitation and Recombination Processes in InAs$\text{}_{x}$P$\text{}_{1-x}$:Yb (x=0.04, 0.07 and 0.11)
Autorzy:
Godlewski, M.
Kozanecki, A.
Karpińska, K.
Bergman, J. P.
Monemar, B.
Powiązania:
https://bibliotekanauki.pl/articles/1932083.pdf
Data publikacji:
1995-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Eq
78.55.Cr
71.35.+z
Opis:
Excitation and recombination mechanisms of Yb$\text{}^{3+}$ 4f-4f intra-shell emission in InP and InAsP (4, 7 and 11% of As) are analyzed.
Źródło:
Acta Physica Polonica A; 1995, 87, 1; 217-220
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonradiative Recombination Processes in (CdTe,CdCrTe)/CdMgTe Quantum Well Structures
Autorzy:
Godlewski, M.
Ivanov, V.
Zakrzewski, A. J.
Wojtowicz, T.
Karczewski, G.
Kossut, J.
Bergman, J. P.
Monemar, B.
Powiązania:
https://bibliotekanauki.pl/articles/1968108.pdf
Data publikacji:
1997-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.60.-p
76.70.Hb
Opis:
Photoluminescence transitions in (CdTe,CdCrTe)/CdMgTe structure grown by molecular beam epitaxy are studied. Photoluminescence investigations show a very strong reduction of the photoluminescence intensity from chromium doped quantum wells. We explain this fact by a very efficient nonradiative recombination in the chromium-doped quantum wells. The present results indicate that the Auger-type energy transfer from excitons to chromium ions is responsible for the photoluminescence deactivation. The efficiency of this process is evaluated.
Źródło:
Acta Physica Polonica A; 1997, 92, 4; 781-784
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:
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:
Optical Properties of ZnCoO Films and Nanopowders
Autorzy:
Wolska, E.
Łukasiewicz, M.
Fidelus, J.
Łojkowski, W.
Guziewicz, E.
Godlewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1791349.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.55.Ln
78.55.Et
81.07.Wx
61.72.uf
78.66.Hf
Opis:
ZnCoO is one of the most studied and promising semiconductor materials for spintronics applications. In this work we discuss optical and electrical properties of ZnCoO films and nanoparticles grown at low temperature by either atomic layer deposition or by a microwave driven hydrothermal method. We report that doping with cobalt quenches a visible photoluminescence of ZnO. We could observe a visible photoluminescence of ZnO only for samples with very low Co fractions (up to 1%). Mechanisms of photoluminescence quenching in ZnCoO are discussed. We also found that ZnO films remained n-type conductive after doping with Co, indicating that a high electron concentration and cobalt 2+ charge state can coexist.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 918-920
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High Pressure Synthesis versus Calcination – Different Approaches to Crystallization of Zirconium Dioxide
Autorzy:
Kaszewski, J.
Yatsunenko, S.
Pełech, I.
Mijowska, E.
Narkiewicz, U.
Godlewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/779250.pdf
Data publikacji:
2014
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
microwave
hydrothermal technology
zirconium dioxide
calcination
Opis:
Calcination and microwave-assisted hydrothermal processing of precipitated zirconium dioxide are compared. Characterization of synthesized products of these two technologies is presented. The infiuence of thermal treatment up to 1200oC on the structural and spectroscopic properties of the so-obtained zirconium dioxide is examined. It was found that initial crystallization of material inhibits the crystal growth up to the 800oC (by means of XRD and TEM techniques), while the material crystallized from amorphous hydroxide precursor at 400oC, exhibits 26 nm sized crystallites already. It was found using the TG technique that the temperature range 100–200oC during the calcination process is equivalent to a microwave hydrothermal process by means of water content. Mass loss is estimated to be about 18%. Based on X-ray investigations it was found that the initial hydroxide precursor is amorphous, however, its luminescence activity suggests the close range ordering in a material.
Źródło:
Polish Journal of Chemical Technology; 2014, 16, 2; 99-105
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Neutron Transmutation Doped GaP: Optically Detected Magnetic Resonance Studies
Autorzy:
Heijmink Liesert, B.
Godlewski, M.
Gregorkiewicz, T.
Ammerlaan, C. A. J.
Goldys, E.
Powiązania:
https://bibliotekanauki.pl/articles/1887198.pdf
Data publikacji:
1991-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.80.Hg
76.70.Hb
Opis:
The first direct proof for successful neutron transmutation doping (NTD) of GaP is presented on the basis of optically detected magnetic resonance (ODMR). GaP:S samples grown by the liquid encapsulated Czochralski method were irradiated with thermal neutrons and subsequently annealed at 800°C. In the ODMR experiments the transmuted Ge substitutional on Ga sites was detected. The NTD process was also found to create deep acceptors, the nature of which will be tentatively discussed.
Źródło:
Acta Physica Polonica A; 1991, 79, 2-3; 401-404
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exciton Dynamics in CdTe/CdMnTe Multiquantum Well Structures Grown by Molecular Beam. Epitaxy on GaAs Substrate
Autorzy:
Godlewski, M.
Koziarska, B.
Suchocki, A.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Bergman, J.
Monemar, B.
Powiązania:
https://bibliotekanauki.pl/articles/1934057.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.60.-p
78.47.+p
73.20.Fz
71.35.+z
Opis:
The results of picosecond photoluminescence kinetics of four different CdTe/CdMnTe multiquantum well structures grown by MBE on GaAs substrates are presented. The experimental results show that excitons in CdTe quantum wells are strongly localized by potential fluctuations. Photoluminescence decay times of the localized excitons are considerably shorter (about 120 ps) than those reported for free or quasi-free excitons. An influence of Mn in the barriers on exciton properties is demonstrated. For narrow quantum wells as well as for the multiquantum well structure with the highest Mn mole fraction the excitons migrate during their decay to the states with a lower potential energy. Longer decay times are observed for quasi-localized excitons. We show also that for strongly localized excitons the energy transfer between localized and donor bound excitons is less efficient.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 985-989
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hot Photoluminescence in CdTe/CdMnTe Quantum Well Structures Grown by Molecular Beam Epitaxy
Autorzy:
Godlewski, M.
Wojtowicz, T.
Karczewski, G.
Kossut, J.
Bergman, J. P.
Holtz, P. O.
Monemar, B.
Powiązania:
https://bibliotekanauki.pl/articles/1968096.pdf
Data publikacji:
1997-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.47.+p
78.55.Et
Opis:
A step-like emission is observed for CdTe/CdMnTe structures δ-doped with In. The new photoluminescence cannot be explained by neither the Raman process nor by the "ordinary" hot photoluminescence. We propose that magnetic interactions are responsible for the new photoluminescence appearing due to a dramatic increase in a thermalization time of hot excitons.
Źródło:
Acta Physica Polonica A; 1997, 92, 4; 765-768
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Photoelectric Properties of ZnSe:Cr and ZnTe:V:Al by Picosecond Four-Wave Mixing Technique
Autorzy:
Kadys, A.
Sudzius, M.
Jarasiunas, K.
Ivanov, V.
Godlewski, M.
Launay, J.-C.
Powiązania:
https://bibliotekanauki.pl/articles/2038157.pdf
Data publikacji:
2004-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.50.Gr
81.70.Fy
61.72.Hh
61.72.Ji
Opis:
Role of deep impurity levels in carrier generation, transport, and recombination were investigated in bulk ZnSe:Cr and ZnTe:V:Al crystals by four-wave mixing technique. The temporal and exposure dependencies of optical nonlinearities in ZnSe:Cr evidenced an influence of Cr1+/Cr2+ states in carrier generation, exhibited very fast carrier relaxation, and revealed the presence of competing recombination mechanisms. Similar investigations in ZnTe:V:Al showed an effective carrier generation from Al-induced defect complexes as well as very fast carrier capture by Zn-vacancies.
Źródło:
Acta Physica Polonica A; 2004, 105, 6; 651-657
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Free Carriers Heating at Mn$\text{}^{2+}$ Magnetic Resonance in CdMnTe
Autorzy:
Godlewski, M.
Gałązka, R. R.
Tsimperidis, I.
Gregorkiewicz, T.
Ammerlaan, C. A. J.
Powiązania:
https://bibliotekanauki.pl/articles/1931938.pdf
Data publikacji:
1995-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Et
76.70.Hb
75.30.Hx
Opis:
The results of optically detected magnetic and cyclotron resonance experiments performed on Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te (x = 0.007) are presented. It is shown that the Mn$\text{}^{2+}$ magnetic resonance results in heating of free holes, which can be observed via the effects of hot holes on the CdMnTe "edge" emission.
Źródło:
Acta Physica Polonica A; 1995, 87, 1; 177-180
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical Characterization of CdZnSe/ZnSe Multiquantum Well System
Autorzy:
Godlewski, M.
Karpińska, K.
Bergman, J. P.
Monemar, B.
Kurtz, E.
Hommel, D.
Powiązania:
https://bibliotekanauki.pl/articles/1932081.pdf
Data publikacji:
1995-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.60.-p
71.35.+z
76.70.Hb
Opis:
Optical properties of Cd$\text{}_{x}$Zn$\text{}_{1-x}$Se/ZnSe (x = 0.12) multiquantum well system are discussed. The transient photoluminescence and optically detected cyclotron resonance experiments demonstrate a strong contribution of bound exciton emission to the low temperature photoluminescence spectra.
Źródło:
Acta Physica Polonica A; 1995, 87, 1; 209-212
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inter-Island Energy Transfer in AlGaAs/GaAs Quantum Wells Grown by Molecular Beam Epitaxy
Autorzy:
Godlewski, M.
Holz, P. O.
Bergman, J. P.
Monemar, B.
Regiński, K.
Bugajski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1952469.pdf
Data publikacji:
1996-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.66.Fd
78.47.+p
73.20.Jc
Opis:
The results of photoluminescence, time-resolved photoluminescence, photoluminescence excitation and photoluminescence kinetics studies are presented for a Al$\text{}_{0.3}$Ga$\text{}_{0.7}$As/GaAs quantum well system grown without growth interruptions at the interfaces. The time-resolved photoluminescence measurements show drift of excitons towards lower energy states induced in a quantum well by potential fluctuations. We present also a first direct evidence for migration of free excitons from the 24 to 25 ML regions of the quantum well and interpret these results within a linear rate model, deriving the transition rate of 290 ps$\text{}^{-1}$. Such inter-island migration processes have been observed till now only in growth interrupted structures.
Źródło:
Acta Physica Polonica A; 1996, 90, 5; 1007-1011
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optically Detected Cyclotron Resonance Studies of CdMnTe/CdTe Multiquantum Wells and CdMgTe/CdMnTe Superlattices
Autorzy:
Godlewski, M.
Świątek, K.
Harris, C. I.
Bergman, J. P.
Monemar, B.
Waag, A.
Powiązania:
https://bibliotekanauki.pl/articles/1932082.pdf
Data publikacji:
1995-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.47.+ρ
76.70.Hb
68.55.Ln
71.35.+z
Opis:
The results of photoluminescence, time resolved photoluminescence (decay times), optically detected cyclotron and magnetic resonances investigations of CdMnTe/CdTe multiquantum wells and CdMgTe/CdMnTe super-lattices are presented. The role of defects and quantum well width fluctuations in recombination processes of 2D carriers is discussed.
Źródło:
Acta Physica Polonica A; 1995, 87, 1; 213-216
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Co$\text{}^{2+}$ Ions in ZnS$\text{}_{x}$Se$\text{}_{1-x}$:Co - ESR and Optical Studies
Autorzy:
Świątek, K.
Surkova, T. P.
Sienkiewicz, A.
Zakrzewski, A. J.
Godlewski, M.
Giriat, W.
Powiązania:
https://bibliotekanauki.pl/articles/1992580.pdf
Data publikacji:
1998-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Gs
76.30.Fc
78.55.Et
Opis:
The electron spin resonance of Co$\text{}^{2+}$ ions in ZnS$\text{}_{x}$Se$\text{}_{1-x}$:Co mixed crystals was measured at temperature of 3 K and microwave frequency of 9.47 GHz. Trigonal Co$\text{}_{Zn}^{2+}$-S center in the ZnS$\text{}_{0.001}$Se$\text{}_{0.999}$:Co crystal was identified and parameters of relevant spin Hamiltonian were determined. Influence of alloy disorder in the anion sublattice on the Co$\text{}_{Zn}^{2+}$ ground and first excited states is briefly discussed.
Źródło:
Acta Physica Polonica A; 1998, 94, 3; 593-596
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Photoluminescence Studies of Cubic Phase GaN Grown by Molecular Beam Epitaxy on (001) Silicon Covered with Sic Layer
Autorzy:
Godlewski, M.
Ivanov, V. Yu.
Bergman, J. P.
Monemar, B.
Barski, A.
Langer, R.
Powiązania:
https://bibliotekanauki.pl/articles/1968103.pdf
Data publikacji:
1997-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Eq
78.47.+p
Opis:
In this work we evaluate optical properties of cubic phase GaN epilayers grown on top of (001) silicon substrate prepared by a new process. Prior to the growth Si substrate was annealed at 1300-1400°C in propane. The so-prepared substrate is covered with a thin (≈ 4 nm) SiC wafer, which allowed a successful growth of good morphological quality cubic phase GaN epilayers. The present results confirm recent suggestion on smaller ionization energies of acceptors in cubic phase GaN epilayers.
Źródło:
Acta Physica Polonica A; 1997, 92, 4; 777-780
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fermi-Edge Singularity in Luminescence Spectra of P-Type Modulation Doped AlGaAs/GaAs Quantum Wells
Autorzy:
Bugajski, M.
Godlewski, M.
Regiński, K.
Holtz, P. O.
Bergman, J. P.
Monemar, B.
Powiązania:
https://bibliotekanauki.pl/articles/1969046.pdf
Data publikacji:
1998-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.55.Px
73.20.Dx
Opis:
We have studied an enhancement of the oscillator strength for optical transitions near the Fermi energy in p-type modulation-doped quantum wells, which, so far, deserved much less attention than analogous n-type systems, because of the complicated valence band structure involved. The relatively wide (L=150 Å) quantum wells and high doping levels were used, containing more than one occupied subband. The enhancement in the photoluminescence intensity at the Fermi energy resulted from the strong correlation and multiple scattering of holes near the Fermi edge by the localized electrons.
Źródło:
Acta Physica Polonica A; 1998, 94, 2; 265-270
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optically Detected Cyclotron Resonance Studies of High Eelectron Mobility AlGaAs/GaAs Structures
Autorzy:
Godlewski, M.
Monemar, B.
Anderson, T. G.
Tsimperidis, I.
Gregorkiewicz, T.
Ammerlaan, C. A. J.
Muszalski, J.
Kaniewska, M.
Powiązania:
https://bibliotekanauki.pl/articles/1934059.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.25.Jd
78.66.Fd
73.40.Kp
73.20.Dx
Opis:
Optically detected cyclotron resonance is used for the identification of recombination transitions of two-dimensional electron gas in A1GaAs/GaAs heterostructures. Two photoluminescence emissions are attributed to the recombination of the two-dimensional electron gas. These are the so-called H-band and the Fermi level singularity photoluminescence. Optical detection of cyclotron resonance is related to the change of the band bending across the GaAs active layer and the AlGaAs barrier, which is caused by impact ionization of shallow donors in the barrier region. Influence of a long range carrier scattering on ionized impurities on a mobility of the two-dimensional carriers is studied.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 990-994
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exciton Transfer in Multiple Quantum Well Structures of CdTe/CdMnTe Grown by Molecular Beam Epitaxy
Autorzy:
Godlewski, M.
Surma, M.
Wilamowski, Z.
Wojtowicz, T.
Karczewski, G.
Kossut, J.
Holtz, P. O.
Bergman, J. P.
Monemar, B.
Powiązania:
https://bibliotekanauki.pl/articles/1968091.pdf
Data publikacji:
1997-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.47.+p
78.55.Et
Opis:
The direct evidence for the efficient transfer of excitons from 4 nm and 6 nm to 10 nm wide CdTe quantum wells is presented based on the results of photoluminescence and photoluminescence excitation investigation. Efficient transfer is observed for quantum wells separated by thick (50 nm) CdMnTe barriers containing 10% or 30% Mn fraction. A new mechanism of the transfer is proposed, which involves long range dynamic magnetic interactions between free/bound excitons and Mn ions in the CdMnTe barrier regions of the structure.
Źródło:
Acta Physica Polonica A; 1997, 92, 4; 761-764
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy Level Position of Ni and Band Offsets in Zn$\text{}_{1-x}$Cd$\text{}_{x}$Sc:Ni and ZnS$\text{}_{x}$Sc$\text{}_{1-x}$:Ni
Autorzy:
Surkova, T.
Giriat, W.
Godlewski, M.
Kaczor, P.
Zakrzewski, A. J.
Permogorov, S.
Tenishev, L.
Powiązania:
https://bibliotekanauki.pl/articles/1934015.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.20.Wc
71.55.Gs
Opis:
Absorption and reflectivity measurements have been carried out for Zn$\text{}_{1-x}$Cd$\text{}_{x}$Se:Ni and ZnS$\text{}_{x}$Se$\text{}_{1-x}$:Ni solid solutions. Energy level positions of nickel 2+/1+ charge state have been used for estimation of band offsets for the valence and conduction bands of ZnCdSe/ZnSe and ZnSSe/ZnSe. Intra-shell transitions of Ni$\text{}^{2+}$ were also studied.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 925-928
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Growth Conditions on Exciton Properties in Thin Quantum Wells of GaAs/AlGaAs
Autorzy:
Godlewski, M.
Bergman, J. P.
Holtz, P. O.
Monemar, B.
Bugajski, M.
Regiński, K.
Kaniewska, M.
Powiązania:
https://bibliotekanauki.pl/articles/1933743.pdf
Data publikacji:
1995-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Cr
73.20.Fz
71.35.+z
Opis:
Exciton properties in growth interrupted quantum wells of GaAs/AlGaAs are compared with those observed for structures grown without growth interruption during the molecular beam epitaxy process. We report observation of quasi-localized excitons in quantum well structures grown without growth interruptions. Quasi-localized excitons drift towards the states of a lower potential energy in the quantum well. For growth interrupted MBE structures islands with a constant quantum well thickness become large compared to the exciton radius. Free or lightly localized excitons are observed in that case.
Źródło:
Acta Physica Polonica A; 1995, 88, 4; 719-722
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Exciton Properties in Quantum Well Structures of ZnCdSe/ZnSe and ZnSe/ZnMgSSe
Autorzy:
Godlewski, M.
Ivanov, V. Yu.
Bergman, J. P.
Monemar, B.
Leonardi, K.
Behringer, M.
Hommel, D.
Powiązania:
https://bibliotekanauki.pl/articles/1969074.pdf
Data publikacji:
1998-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.-y
73.20.Mf
73.20.Dx
Opis:
Properties of excitons in quantum well structures of ZnCdSe/ZnSe and ZnSe/ZnMgSSe are compared. In ternary ZnCdSe quantum wells and at low temperature excitons are strongly localised. Weaker localization is observed in quantum well structures of ZnSe/ZnMgSSe. Present studies suggest formation of negatively charged excitons in the latter structures.
Źródło:
Acta Physica Polonica A; 1998, 94, 2; 313-316
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanism of Optical Detection of Magnetic Resonance in Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te
Autorzy:
Godlewski, M.
Surma, M.
Gałązka, R. R.
Nguyen, The Khoi
Gisbergen, S.J.C.H.M.
Gregorkiewicz, T.
Ammerlaan, C. A. J.
Powiązania:
https://bibliotekanauki.pl/articles/1921620.pdf
Data publikacji:
1992-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
76.70.Hb
75.50.Pp
78.20.Ls
Opis:
The photoluminescence and optically detected magnetic resonance studies of Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te (x = 0.095) are presented. The Mn$\text{}^{2+}$ magnetic resonance is detected optically via the changes of "edge" emission induced by the decrease of the Mn spin system magnetization.
Źródło:
Acta Physica Polonica A; 1992, 82, 4; 717-719
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optically Detected Magnetic Resonance Studies of Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te (x=0.095, 0.007)
Autorzy:
Godlewski, M.
Świątek, K.
Gałązka, R. R.
Monemar, B.
van Loosdrecht, P. H. M.
Wittlin, A.
Perenboom, J. A. A. J.
Powiązania:
https://bibliotekanauki.pl/articles/1929637.pdf
Data publikacji:
1993-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
76.70.Hb
78.55.Et
71.35.+z
Opis:
The dominant mechanism responsible for the optical detection of the Mn$\text{}^{2+}$ magnetic resonance in Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te (x = 0.095, 0.007) is explained. By either change of the external magnetic field or by setting the conditions for the Mn$\text{}^{2+}$ magnetic resonance, we could change the relative efficiencies of the two competing excitonic recombination processes. By lowering magnetization at the magnetic resonance, recombination via the acceptor bound exciton channel, which is mainly nonradiative, is enhanced. Then, a large up to 50% decrease in the total photoluminescence efficiency was observed in the optically detected magnetic resonance experiment. Such observation allows for verification of the large efficiency of the Auger-type transition responsible for the nonradiative decay of the acceptor bound exciton.
Źródło:
Acta Physica Polonica A; 1993, 84, 3; 539-542
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monocrystalline and Polycrystalline ZnO and ZnMnO Films Grown by Atomic Layer Epitaxy - Growth and Characterization
Autorzy:
Wójcik, A.
Kopalko, K.
Godlewski, M.
Łusakowska, E.
Paszkowicz, W.
Dybko, K.
Domagała, J.
Szczerbakow, A.
Kamińska, E.
Powiązania:
https://bibliotekanauki.pl/articles/2038164.pdf
Data publikacji:
2004-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.55.Jk
68.55.Ln
68.55.Nq
78.66.Hf
81.15.Kk
Opis:
Recently we demonstrated growth of monocrystalline ZnO films by atomic layer epitaxy in the gas flow variant using inorganic precursors. In this study, we discuss properties of ZnO films grown with organic precursors. Successful Mn doping of the ZnO films during the growth was achieved using the Mn-thd complex. Secondary ion mass spectroscopy and X-ray investigations reveal the contents of Mn up to about 20% of the cationic component.
Źródło:
Acta Physica Polonica A; 2004, 105, 6; 667-673
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamics of Light Emission in CdMnS Nanoparticles
Autorzy:
Godlewski, M.
Yatsunenko, S.
Drozdowicz-Tomsia, K.
Goldys, E. M.
Phillips, M. R.
Klar, P. J.
Heimbrodt, W.
Powiązania:
https://bibliotekanauki.pl/articles/2043717.pdf
Data publikacji:
2005-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.07.Wx
78.55.Et
78.47.+p
71.55.Gs
76.30.Fc
76.70.Hb
Opis:
We demonstrate coexistence of slow and fast components of photoluminescence decay of the Mn$\text{}^{2+}$ intra-shell emission in nanoparticles of CdMnS. We explain the observed decrease in PL lifetime of the Mn$\text{}^{2+}$ intra-shell transition by high efficiency of spin dependent magnetic interactions between localized spins of Mn$\text{}^{2+}$ ions and free carriers. This mechanism is enhanced in nanostructures, but it is also present in bulk samples.
Źródło:
Acta Physica Polonica A; 2005, 108, 4; 681-688
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cathodoluminescence Profiling for Checking Uniformity of ZnO and ZnCoO Thin Films
Autorzy:
Witkowski, B. S.
Łukasiewicz, M. I.
Wolska, E. A.
Kopalko, K.
Kowalski, B. J.
Guziewicz, E.
Godlewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/2048105.pdf
Data publikacji:
2011-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.15.Gh
78.30.Fs
78.60.Hk
Opis:
We employ scanning electron microscopy and cathodoluminescence for evaluation of uniformity of ZnCoO films obtained by the atomic layer deposition. Cathodoluminescence quenching by Co ions allows us to detect (regions of weaker light emission) Co accumulations, with the resolution limited by diffusion length of secondary carriers.
Źródło:
Acta Physica Polonica A; 2011, 119, 5; 675-677
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrid Organic/ZnO p-n Junctions, with n-Type ZnO, Grown by Atomic Layer Deposition
Autorzy:
Łuka, G.
Krajewski, T.
Szczerbakow, A.
Łusakowska, E.
Kopalko, K.
Guziewicz, E.
Wachnicki, Ł.
Szczepanik, A.
Godlewski, M.
Fidelus, J.
Powiązania:
https://bibliotekanauki.pl/articles/1811956.pdf
Data publikacji:
2008-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.55.J-
73.40.Lq
81.05.Lg
Opis:
We report on fabrication of hybrid inorganic-on-organic thin film structures with polycrystalline zinc oxide films grown by atomic layer deposition technique. ZnO films were deposited on two kinds of thin organic films, i.e. pentacene and poly(dimethylosiloxane) elastomer with a carbon nanotube content (PDMS:CNT). Surface morphology as well as electrical measurements of the films and devices were analyzed. The current density versus voltage (I-V) characteristics of ITO/pentacene/ZnO/Au structure show a low-voltage switching phenomenon typical of organic memory elements. The I-V studies of ITO/PDMS:CNT/ZnO/Au structure indicate some charging effects in the system under applied voltages.
Źródło:
Acta Physica Polonica A; 2008, 114, 5; 1229-1234
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
ZnO by ALD - Advantages of the Material Grown at Low Temperature
Autorzy:
Guziewicz, E.
Godlewski, M.
Krajewski, T.
Wachnicki, Ł.
Łuka, G.
Paszkowicz, W.
Domagała, J.
Przeździecka, E.
Łusakowska, E.
Witkowski, B.
Powiązania:
https://bibliotekanauki.pl/articles/1791286.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.61.Ga
78.66.Hf
72.80.Ey
Opis:
The 3D-architecture is a prospective way in miniaturization of electronic devices. However, this approach can be realized only if metal paths are placed not only at the top, but also beneath the electronic parts, which imposes drastic temperature limitations for the electronic device processing. Therefore last years a lot of investigations are focused on materials which can be grown at low temperature with electrical parameters appropriate for electronic applications. Zinc oxide grown by the atomic layer deposition method is one of the materials of choice. We obtained ZnO-ALD films at growth temperature range between 100°C and 200°C, and with controllable electrical parameters. Free carrier concentration was found to scale with deposition temperature, so it is possible to grow ZnO films with desired conductivity without any intentional doping. We used correlation of electrical and optical parameters to optimize the deposition process. Zinc oxide layers obtained in that way have free carrier concentration as low as $10^{16} cm^{-3}$ and high mobility ($10-50 cm^{2}$/(Vs)), which satisfies requirements for a material used in three-dimensional memories.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 814-817
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanisms of Yellow and Red Photoluminescence in Wurtzite and Cubic GaNDOI
Autorzy:
Godlewski, M.
Suski, T.
Grzegory, I.
Porowski, S.
Langer, R.
Barski, A.
Bergman, J. P.
Monemar, B.
Goldys, E. M.
Phillips, M. R.
Powiązania:
https://bibliotekanauki.pl/articles/1969079.pdf
Data publikacji:
1998-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.16.Ch
61.72.Ff
71.55.Eq
Opis:
The origin of two "deep" photoluminescence (PL) emissions observed in wurtzite (yellow PL) and cubic (red PL) GaN is discussed. PL and time-resolved PL studies confirm donor-acceptor pair character of the yellow band in wurtzite GaN and point to participation of shallow donors in this emission. A similar PL mechanism is proposed for the red emission of cubic GaN. We further show a puzzling property of both yellow and red PLs. Both yellow and red emissions show spatial homogeneity and are only weakly dependent on surface morphology.
Źródło:
Acta Physica Polonica A; 1998, 94, 2; 326-330
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Origin of Ultrafast Component of Photoluminescence Decay in Nanostructures Doped with Transition Metal or Rare-Earth Ions
Autorzy:
Godlewski, M.
Yatsunenko, S.
Ivanov, V. Yu.
Khachapuridze, A.
Świątek, K.
Goldys, E. M.
Phillips, M. R.
Klar, P. J.
Heimbrodt, W.
Powiązania:
https://bibliotekanauki.pl/articles/2041630.pdf
Data publikacji:
2005-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Gs
76.30.Fc
76.70.Hb
78.55.Et
Opis:
Bulk samples, layers, quantum well, and quantum dot structures of II-Mn-VI samples all show coexistence of slow and fast components of Mn$\text{}^{2+}$ photoluminescence decay. Thus, fast photoluminescence decay cannot be related to low dimensionality of a host material. This also means that the model of the so-called quantum confined atom is incorrect. Based on the results of time-resolved photoluminescence and optically detected magnetic resonance investigations we relate the observed lifetime decrease in Mn$\text{}^{2+}$ intra-shell transition to spin dependent magnetic interactions between localized spins of Mn$\text{}^{2+}$ ions and between Mn$\text{}^{2+}$ ions and spins/magnetic moments of free carriers. The latter mechanism is enhanced in nanostructures.
Źródło:
Acta Physica Polonica A; 2005, 107, 1; 65-74
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microwave-Induced Delocalization of Excitons in Ternary Compounds of II-VI and III-V Semiconductors
Autorzy:
Ivanov, V. Yu.
Godlewski, M.
Khachapuridze, A.
Yatsunenko, S.
Wojtowicz, T.
Karczewski, G.
Bergman, J. P.
Monemar, B.
Shamirzaev, T.
Zhuravlev, K.
Leonardi, K.
Hommel, D.
Powiązania:
https://bibliotekanauki.pl/articles/2035757.pdf
Data publikacji:
2003-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.Ji
72.25.Rb
76.70.Hb
78.55.Et
Opis:
In this work we employ technique of optically detected cyclotron resonance for evaluation of the role of localization processes in CdTe/CdMnTe and CdMnTe/CdMgTe quantum well structures. From microwave-induced changes of excitonic emissions we evaluate magnitude of potential fluctuations (Stokes shift), correlate optically detected cyclotron resonance results with the results of time-resolved experiments and discuss nature of recombination processes in the limit of a strong localization.
Źródło:
Acta Physica Polonica A; 2003, 103, 6; 559-566
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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