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Tytuł:
Crack Free GaInN/AlInN Multiple Quantum Wells Grown on GaN with Strong Intersubband Absorption at 1.55μm
Autorzy:
Cywiński, G.
Skierbiszewski, C.
Feduniewicz-Żmuda, A.
Siekacz, M.
Nevou, L.
Doyennette, L.
Julien, F. H.
Prystawko, P.
Kryśko, M.
Grzanka, S.
Grzegory, I.
Porowski, S.
Powiązania:
https://bibliotekanauki.pl/articles/2046911.pdf
Data publikacji:
2006-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.65.Fg
78.66.-w
78.67.De
78.40.Fy
81.15.Hi
Opis:
Crack free GaInN/AlInN multiple quantum wells were grown by rf plasma-assisted molecular beam epitaxy on (0001) GaN/sapphire substrates. The strain-engineering concept was applied to eliminate cracking effect for growth of intersubband structures on GaN. Indium contained ternary compounds of barrier and well layers are contrary strained to the substrate material. A series of crack free GaInN/AlInN intersubband structures on (0001) GaN was fabricated and investigated. The assumed composition and layered structure were confirmed by room temperature photoluminescence and X-ray diffraction measurements. The intersubband measurements were done in multipass waveguide geometry by applying direct intersubband absorption and photoinduced intersubband absorption measurements. The optimized structure design contains forty periods of Si-doped GaInN/AlInN quantum wells and exhibits strong intersubband absorption.
Źródło:
Acta Physica Polonica A; 2006, 110, 2; 175-181
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-Electron Transition in Homoepitaxial GaN Layers
Autorzy:
Fiorek, A.
Baranowski, J. M.
Wysmołek, A.
Pakuła, K.
Wojdak, M.
Grzegory, I.
Porowski, S.
Powiązania:
https://bibliotekanauki.pl/articles/1968067.pdf
Data publikacji:
1997-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.66.Fd
78.55.Cr
Opis:
It is shown that the luminescence mapping is a powerful method to help identify optical transitions. Two-electron transition was identified in the homoepitaxial GaN layer by this technique. It was found that the donor and acceptor bound exciton emissions are spatially displaced and show intensity maxima at different places of the epitaxial layer. It was also found that the 3.45 eV line, suspected as "two-electron transition", follows exactly the donor bound exciton spatial distribution. Donor bound exciton recombines leaving the neutral donor in the excited 2s state. Thus, 1s-2s excitation being equal to 22 meV corresponds to 29 meV hydrogenic donor binding energy. This is the first identification of the two-electron transition in GaN.
Źródło:
Acta Physica Polonica A; 1997, 92, 4; 742-744
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cathodoluminescence Profiling of InGaN-Based Quantum Well Structures and Laser Diodes - In-Plane Instabilities of Light Emission
Autorzy:
Godlewski, M.
Ivanov, V. Yu.
Goldys, E. M.
Phillips, M.
Böttcher, T.
Figge, S.
Hommel, D.
Czernecki, R.
Prystawko, P.
Leszczynski, M.
Perlin, P.
Grzegory, I.
Porowski, S.
Powiązania:
https://bibliotekanauki.pl/articles/2036870.pdf
Data publikacji:
2003-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.72.Ff
61.72.Mm
68.37.Hk
78.60.Hk
Opis:
Instabilities of light emission and also of stimulated emission in series of GaN epilayers and InGaN quantum well structures, including laser diode structures, are studied. A stimulated emission is observed under electron beam pumping. This enabled us to study light emission properties from laser structures and their relation to microstructure details. We demonstrate large in-plane fluctuations of light emission and that these fluctuations are also present for excitation densities larger than the threshold densities for the stimulated emission.
Źródło:
Acta Physica Polonica A; 2003, 103, 6; 689-694
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:
Relationship between Sample Morphology and Carrier Diffusion Length in GaN Thin Films
Autorzy:
Godlewski, M.
Goldys, E. M.
Phillips, M.
Böttcher, T.
Figge, S.
Hommel, D.
Czernecki, R.
Prystawko, P.
Leszczynski, M.
Perlin, P.
Wisniewski, P.
Suski, T.
Bockowski, M.
Grzegory, I.
Porowski, S.
Powiązania:
https://bibliotekanauki.pl/articles/2035593.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.72.Ff
61.72.Mm
68.37.Hk
78.60.Hk
Opis:
Scanning and spot-mode cathodoluminescence investigations of homo- and hetero-epitaxial GaN films indicate a surprisingly small influence of their microstructure on overall intensity of a light emission. This we explain by a correlation between structural quality of these films and diffusion length of free carriers and excitons. Diffusion length increases with improving structural quality of the samples, which, in turn, enhances the rate of nonradiative recombination on structural defects, such as dislocations.
Źródło:
Acta Physica Polonica A; 2002, 102, 4-5; 627-632
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Observation of Magnetic Anisotropy in Bulk GaMnN:Mg Crystals
Autorzy:
Gosk, J.
Zając, M.
Kamińska, M.
Twardowski, A.
Grzegory, I.
Boćkowski, M.
Porowski, S.
Powiązania:
https://bibliotekanauki.pl/articles/2036861.pdf
Data publikacji:
2003-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Eq
75.30.Gw
75.50.Pp
Opis:
Magnetic properties of bulk wurtzite n-type GaMnN and highly resistive GaMnN:Mg monocrystals were studied for the magnetic field applied parallel and perpendicular to the crystal hexagonal c-axis. Magnetization of both types of samples reveals paramagnetic behavior. However, for n-type GaMnN isotropic magnetization was observed which is in agreement with Mn d$\text{}^{5}$ configuration. On the other hand, GaMnN co-doped with Mg shows large magnetic anisotropy which suggests Mn to be in nonspherical d$\text{}^{4}$ or d$\text{}^{3}$ configuration.
Źródło:
Acta Physica Polonica A; 2003, 103, 6; 665-669
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Blue Laser on High N$\text{}_{2}$ Pressure-Grown Bulk GaN
Autorzy:
Grzegory, I.
Boćkowski, M.
Krukowski, S.
Łucznik, B.
Wróblewski, M.
Weyher, J.
Leszczyński, M.
Prystawko, P.
Czernecki, R.
Lehnert, J.
Nowak, G.
Perlin, P.
Teisseyre, H.
Purgał, W.
Krupczyński, W.
Suski, T.
Dmowski, L.
Litwin-Staszewska, E.
Skierbiszewski, C.
Łepkowski, S.
Porowski, S.
Powiązania:
https://bibliotekanauki.pl/articles/2030423.pdf
Data publikacji:
2001-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Opis:
In this note we report briefly on the details of pulsed-current operated "blue" laser diode, constructed in our laboratories, which utilizes bulk GaN substrate. As described in Ref. [1] the substrate GaN crystal was grown by HNPSG method, and the laser structure was deposited on the conducting substrate by MOCVD techniques (for the details see Sec. 2 and Sec. 4 of Ref.~[1], respectively).
Źródło:
Acta Physica Polonica A; 2001, 100, Supplement; 229-232
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Application of High Pressure in Physics and Technology of III-V Nitrides
Autorzy:
Grzegory, I.
Leszczyński, M.
Krukowski, S.
Perlin, P.
Suski, T.
Porowski, S.
Powiązania:
https://bibliotekanauki.pl/articles/2030388.pdf
Data publikacji:
2001-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.10.-h
78.66.Fd
73.61.Ey
82.60.Lf
78.55.Cr
Opis:
Due to high bonding energy of N$\text{}_{2}$ molecule, the III-V semiconducting nitrides, especially GaN and InN require high N$\text{}_{2}$ pressure to be stable at high temperatures necessary for growth of high quality single crystals. Physical properties of GaN-Ga(l)-N$\text{}_{2}$ system are discussed in the paper. On the basis of the experimental equilibrium p-T-x data and the quantum-mechanical modeling of interaction of N$\text{}_{2}$ molecule with liquid Ga surface, the conditions for crystallization of GaN were established. The crystals obtained under high pressure are of the best structural quality, having dislocation density as low as 10-100 cm$\text{}^{-2}$ which is several orders of magnitude better than in any other crystals of GaN. The method allows to grow both n-type substrate crystals for optoelectronics and highly resistive crystals for electronic applications. The physical properties of the pressure grown GaN measured to characterize both point defects and extended defects in the crystal lattice are discussed in the paper. A special attention is paid to the application of high pressure to reveal the nature of the point defects in the crystals and electric fields in GaN-based quantum structures. Due to their very high structural quality, the pressure grown crystals are excellent substrates for epitaxial growth of quantum structures. It opens new possibilities for optoelectronic devices, especially short wavelength high power lasers and efficient UV light emitting diodes. This is due to the strong reduction in dislocation densities in relation to existing structures (10$\text{}^{6}$-10$\text{}^{8}$ cm$\text{}^{-2}$) which are grown on strongly mismatched sapphire and SiC substrates. The experimental results on the epitaxial growth and physical properties of GaN-based device structures supporting above conclusions are discussed in the paper. The current development of blue laser technology in High Pressure Research Center is shortly reviewed.
Źródło:
Acta Physica Polonica A; 2001, 100, Supplement; 57-109
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Electric Field on Recombination Dynamics of Quantum Confined Carriers
Autorzy:
Korona, K. P.
Borysiuk, J.
Skierbiszewski, C.
Porowski, S.
Powiązania:
https://bibliotekanauki.pl/articles/2047384.pdf
Data publikacji:
2007-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.47.+p
72.20.Jv
78.55.Cr
Opis:
We present time-resolved photoluminescence measurements of GaN/AlGaN low dimensional structures showing very characteristic changes of dynamics related to strong electric field. Strong piezoelectric and spontaneous polarizations built-in in nitride structures lead to the changes in spatial separation of carriers which leads to changes in recombination energies and radiative lifetimes of the carriers. The observed effect can be well described by a simple exponential relation. The observed dependence can be explained by an approximated model of quantum-confined Stark effect based on the Airy functions.
Źródło:
Acta Physica Polonica A; 2007, 112, 2; 243-247
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Luminescence Dynamics of Exciton Replicas in Homoepitaxial GaN Layers
Autorzy:
Korona, K. P.
Baranowski, J. M.
Pakuła, K.
Monemar, B.
Bergman, J. P.
Grzegory, I.
Porowski, S.
Powiązania:
https://bibliotekanauki.pl/articles/1968240.pdf
Data publikacji:
1997-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.-y
78.47.+p
78.55.Cr
Opis:
Photoluminescence of excitons and their phonon replicas in homoepitaxial MOCVD-grown gallium nitride (GaN) layers have been studied by picosecond (ps) time-resolved photoluminescence spectroscopy. The time-resolved photoluminescence spectroscopy has shown that the free excitons and their replicas have the fastest dynamics (decay time of about 100 ps). Then, the excitons-bound-to-donors emission rises (with the rise time similar to the free excitons decay time) and decays with t=300 ps. The excitons-bound-to-acceptors has the slowest decay (about 500 ps). It has been found that the ratio of excitons-bound-to-acceptors and excitons-bound-to-donors amplitudes and their decay times are different for 1-LO replicas and then for zero-phonon lines, whereas the ratio of amplitudes and the decay time of the 2-LO replicas are similar to the ones of the zero-phonon lines.
Źródło:
Acta Physica Polonica A; 1997, 92, 4; 841-844
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MnAs Overlayer on GaN(000$\text{}_{1}$)-(1 x 1) - Its Growth, Morphology and Electronic Structure
Autorzy:
Kowalski, B. J.
Kowalik, I. A.
Iwanowski, R. J.
Łusakowska, E.
Sawicki, M.
Sadowski, J.
Grzegory, I.
Porowski, S.
Powiązania:
https://bibliotekanauki.pl/articles/2038151.pdf
Data publikacji:
2004-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.55.-a
73.20.At
Opis:
MnAs layer has been grown by means of MBE on the GaN(000$\text{}_{1}$)-(1 x 1) surface. Spontaneous formation of MnAs grains with a diameter of 30-60 nm (as observed by atomic force microscopy) occurred for the layer thickness bigger than 7 ML. Ferromagnetic properties of the layer with Curie temperature higher than 330 K were detected by SQUID measurements. Electronic structure of the system was investigated in situ by resonant photoemission spectroscopy for MnAs layer thickness of 1, 2, and 8 ML. Density of the valence band states of MnAs and its changes due to the increase in the layer thickness were revealed.
Źródło:
Acta Physica Polonica A; 2004, 105, 6; 645-650
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crystallographic Properties of Bulk GaN Crystals Grown at High Pressure
Autorzy:
Leszczyński, M.
Grzegory, I.
Bockowski, M.
Jun, J.
Porowski, S.
Jasiński, J.
Baranowski, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/1933847.pdf
Data publikacji:
1995-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.72.Dd
61.50.Cj
Opis:
Gallium nitride bulk crystals grown at about 15 kbar and 1500 K have been examined by using the high resolution X-ray diffractometry. An analysis of a set of the rocking curves of various Bragg reflections enabled us to estimate a dislocation density. For the crystals of dimensions lower than about 1 mm it is lower than 10$\text{}^{-5}$ cm$\text{}^{-2}$. For bigger samples the crystallographic quality worsens. With an application of the reciprocal lattice mapping we could distinguish between internal strains and mosaicity which are both present in these crystals The results for the bulk crystals are compared with those for epitaxial layers.
Źródło:
Acta Physica Polonica A; 1995, 88, 4; 799-802
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polarity Related Problems in Growth of GaN Homoepitaxial Layers
Autorzy:
Leszczyński, M.
Prystawko, P.
Śliwinski, A.
Suski, T.
Litwin-Staszewska, E.
Porowski, S.
Paszkiewicz, R.
Tłaczała, M.
Beaumont, B.
Gibart, P.
Barski, A.
Langer, R.
Knap, W.
Frayssinet, E.
Powiązania:
https://bibliotekanauki.pl/articles/1991873.pdf
Data publikacji:
1998-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.72.Vv
65.70.+y
Opis:
Homoepitaxial layers of GaN were grown by metalorganic chemical vapour deposition on single crystals obtained by high-pressure, high-temperature technology. For each metalorganic chemical vapour deposition run, four samples were placed, (00.1) and (00.1̲) faces of the Mg-doped insulating and undoped highly-conductive substrates. The layers were examined using X-ray diffraction, photoluminescence and far-infrared reflectivity. It was found that the (00.1̲) easier incorporates donors resulting in higher free-electron concentrations in the layers grown on these sides of the crystals, both, undoped and Mg-doped.
Źródło:
Acta Physica Polonica A; 1998, 94, 3; 427-430
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal Expansion of GaN Bulk Crystals and Homoepitaxial Layers
Autorzy:
Leszczyński, M.
Teisseyre, H.
Suski, T.
Grzegory, I.
Boćkowski, M.
Jun, J.
Pałosz, B.
Porowski, S.
Pakuła, K.
Baranowski, J. M.
Barski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1952040.pdf
Data publikacji:
1996-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.72.Ji
61.72.Vv
Opis:
Thermal expansion of gallium nitride was measured using high resolution X-ray diffraction. The following samples were examined: (i) single monocrystals grown at pressure of about 15 kbar, (ii) homoepitaxial layers. The main factor influencing both, the lattice parameters and the thermal expansion coefficient, are free electrons related to the nitrogen vacancies. The origin of an increase in the lattice constants by free electrons is discussed in terms of the deformation potential of the conduction-band minimum. An increase of the thermal expansion by free electrons is explained by a decrease of elastic constants.
Źródło:
Acta Physica Polonica A; 1996, 90, 5; 887-890
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Propozycje poprawy zarządzania bezpieczeństwem w cyklu transportowym przewozów drogowych towarów niebezpiecznych
Proposals for improvement of safety management in the cycle of road transport of dangerous goods
Autorzy:
Michalik, J. S.
Gajek, A.
Janik, P.
Zając, S.
Koniuch, A.
Obolewicz, A.
Porowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/180892.pdf
Data publikacji:
2011
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
transport drogowy
transport chemikaliów
transport towarów niebezpiecznych
road transport
liquid fuels
dangerous goods transport
Opis:
Uwzględniając główną przyczynę zdarzeń awaryjnych w przewozie drogowym towarów niebezpiecznych - niezachowanie zasad bezpieczeństwa ruchu - określono rodzaje środków i działań umożliwiających poprawę bezpieczeństwa ich transportu. Wykonane analizy wykazały, że system szkolenia osób związanych z przewozem towarów niebezpiecznych, system organizacyjny jednostek ratownictwa PSP oraz procedury reagowania i zwalczania skutków awarii transportowych są zorganizowane w Polsce na wysokim poziomie i funkcjonują prawidłowo. W tej sytuacji zmniejszenie ryzyka wypadku drogowego o cechach poważnej awarii można osiągnąć w wyniku wyboru najbardziej właściwej trasy przewozowej. Została zaproponowana metoda wyboru najkorzystniejszej z punktu widzenia poziomu ryzyka przebiegu trasy przewozu towarów niebezpiecznych, oparta na ocenie pasa terenu 1,5 km od osi drogi pod względem demograficznym oraz występowania obiektów użyteczności publicznej i elementów środowiska o szczególnej wrażliwości, a także na ocenie szeregu parametrów techniczno-konstrukcyjnych trasy, dotyczących podstawowych cech ruchu drogowego.
This article defines the types of measures and actions for improving safety of road transport of dangerous goods taking into account the main cause of accidents with the attributes of major accidents in road transport of dangerous goods, i. e., disregard for traffic rules. Analyses showed that the system of training persons involved in transport of dangerous goods, the organizational system of the State Fire Service rescue units, and the procedures for responding and mitigating the effects of transport accidents in Poland are good and that they function properly. In this situation, selecting the most appropriate transport routes can reduce the risk of an accident with the attributes of a major accident. This article proposes a method of selecting the least risky transport route for dangerous goods by evaluating a strip of land 15 km from the axis of the road in terms of demographics, public Utilities, particularly sensitive environment as well as by evaluating a number of technical and construction parameters of routes related to the basie features of road traffic.
Źródło:
Bezpieczeństwo Pracy : nauka i praktyka; 2011, 5; 24-27
0137-7043
Pojawia się w:
Bezpieczeństwo Pracy : nauka i praktyka
Dostawca treści:
Biblioteka Nauki
Artykuł

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