Wyniki wyszukiwania - Biblioteka Nauki

1

Diagnosing Toxoplasma gondii infection during pregnancy - a case study

100%

Karczewski G. , Golab E.

Annals of Parasitology

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2016

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tom 62

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nr Suppl.

2

Limitations of serological screening of Toxoplasma gondii infection

80%

Karczewski G. , Salamatin R. , Konieczna-Salamatin J. , Golab E.

Annals of Parasitology

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2013

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tom 59

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nr Suppl.

3

CdTe/Cd1-xMnxTe quantum structures investigated by photoreflectance spectroscopy

70%

Sitarek P. , Misiewicz J. , Karczewski G. , Wójtowicz T. , Kossut J.

Electron Technology

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1998

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tom Vol. 31, No. 3/4

311-314

EN

Room temperature photoreflectance spectroscopy was used to investigate Cd1-xMnxTe/CdTe quantum structures grown by MBE technique. The system of four quantum wells of x = 0.28 with different thicknesses was under study first. The obtained spectrum showed a series of resonances which are attributed to the intersubband transitions. The second group of quantum structures were CdTe/Cd1-xMnxTe MQW. The samples were δ-doped in the middle of the wells by using indium. Transitions related to heavy holes in δ-doped wells were found to occur at different energies thaqn those in undoped wells. The influence of the strains on (CdMn)Te/CdTe quantum stryctures has been taken into account.

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Raman spectroscopy of CdTe/ZnTe quantum dot structures

70%

Zielony E. , Placzek-Popko E. , Kamyczek P. , Henrykowski A. , Karczewski G.

Optica Applicata

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2013

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tom Vol. 43, nr 1

181--185

EN

Semiconductor low-dimensional structures of CdTe quantum dots (QDs) embedded in ZnTe matrix have been investigated by micro-Raman spectroscopy. A reference ZnTe sample (without dots) was also studied for comparison. Both samples were grown by a molecular beam epitaxy technique on the p-type GaAs substrate. The Raman measurements have been performed at room temperature. The samples were excited by an Ar2+ laser of 514.5 nm wavelength. The Raman spectra have been recorded for different acquisition parameters of the measurement. For the reference and QD sample localized longitudinal (LO) phonons of 210 cm–1 wavenumber associated with the ZnTe layer are observed. In the case of QD sample another broadband corresponding to the LO CdTe phonon related to the QD-layer appears at a wavenumber of 160 cm–1. Such behaviour does not exhibit the Raman spectra of the reference sample. Thus the Raman measurements confirm the presence of CdTe layer of quantum dots in the investigated material. Additionally, Raman spectra for both samples exhibit tellurium-related peaks at wavenumbers around 120 cm–1 and 140 cm–1, significantly increasing with laser time exposure. It is shown that the peaks are associated with the formation of Te aggregates on the ZnTe surface due to the laser damage in the ZnTe layer.

5

Aktywność defektów w pomiarach elektrycznych i optycznych złączy fotowoltaicznych na bazie CdTe

61%

Zielony E. , Morawski M. , Racino A. , Płaczek-Popko E. , Gumienny Z. , Chusnutdinow S. , Karczewski G.

Przegląd Elektrotechniczny

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2016

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tom R. 92, nr 9

43--46

PL

W niniejszym artykule przedstawione zostały wyniki badań defektów w strukturach fotowoltaicznych na bazie CdTe, otrzymanych techniką epitaksji z wiązek molekularnych (MBE). Do charakteryzacji defektów w badanych złączach wykorzystano różne metody pomiarowe, takie jak: charakterystyki prądowo-napięciowe, niestecjonarna spektroskopia głębokich poziomów (DLTS) i fotoluminescencja (PL), mierzone w szerokim zakresie temperatur. Pokazano, że sprawności badanych diod są stosunkowo niskie, na co mają wpływ defekty występujące w ich strukturze. W oparciu o wyniki pomiarów widm DLTS i PL wyznaczono parametry defektów oraz określono źródło ich pochodzenia.

EN

In this article the results of investigations of defects in photovoltaic structures based on CdTe grown by the molecular beam epitaxy (MBE) technique have been presented. For the characterization of defects in the studied junctions various measurement methods have been used, such as: current-voltage characteristics, deep level transient spectroscopy (DLTS) and photoluminescence (PL), measured in a broad temperature range. It has been shown that the efficiency of the investigated diodes are relatively low, what is caused by the defects present in their structure. Based on the results of the DLTS- and PL spectra the parameters of defects have been determined and their possible origin has been discussed.

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Raman scattering studies of MBE-grown ZnTe nanowires

51%

Szuszkiewicz W. , Morhange J. F. , Dynowska E. , Janik E. , Zaleszczyk W. , Presz A. , Domagała J. Z. , Caliebe W. , Karczewski G. , Wojtowicz T.

Materials Science Poland

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2008

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tom Vol. 26, No. 4

1054--1059

EN

We report on the first studies of the optical properties of MBE-grown ZnTe nanowires (NWs). The growth of ZnTe NWs was based on the Au-catalyzed vapour–liquid–solid mechanism and was performed on (001), (011), or (111)B-oriented GaAs substrates. Investigated NWs have a zinc-blende structure, the average diameter of about 30 nm, and typical length between 1 and 2 μm. Their growth axes are oriented along <111>-type directions of the substrate. The structural characterization of the NWs was performed by means of X-ray diffraction, using the synchrotron radiation corresponding to the wavelength of CuKα1 radiation W1 beamline at Hasylab DESY). The macro-Raman spectra of either as-grown NWs on GaAs substrate or of NWs removed from substrate and deposited onto Si were collected at temperatures from 15 K to 295 K using Ar+ and Kr+ laser lines. Strong enhancement of ZnTe-related LO-phonon structure was found for an excitation close to the exciton energy. Our studies revealed also the presence of small trigonal Te precipitates, typical of tellurium compounds.

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Wstępne wyniki badań w kierunku Enerocytozoon bieneusi i Encephalitozoon intestinalis u osób z obniżoną odpornością

51%

Golab E. , Waloch M. , Wnukowska N. , Podlasin R. , Latarska D. , Karczewski G. , Magdziak A. , Pracka H.

Wiadomości Parazytologiczne. Suplement

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2004

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tom 50