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Wyszukujesz frazę "Korona, K. P." wg kryterium: Wszystkie pola


Tytuł:
A Model of Radiative Recombination in (In,Al,Ga)N/GaN Structures with Significant Potential Fluctuations
Autorzy:
Dróżdż, P.
Korona, K.
Sarzyński, M.
Czernecki, R.
Skierbiszewski, C.
Muzioł, G.
Suski, T.
Powiązania:
https://bibliotekanauki.pl/articles/1185815.pdf
Data publikacji:
2016-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Cr
73.22.-f
78.47.jd
Opis:
The potential fluctuations in III-nitride quantum wells lead to many effects like emission broadening and S-shape energy vs. temperature dependence. The best description of the energy dependence comes from calculations based on Gaussian density of states. However, in most of the published reports, changes of carrier lifetime with energy and temperature are not taken into account. Since experimental evidence shows that lifetime significantly depends on energy and temperature, here we propose a model that describes two basic parameters of luminescence: lifetime of carries and emission energy as a function of temperature in the case of quantum wells and layers that are characterized by potential fluctuations. Comparison of the measured energy and lifetime dependences on temperature in specially grown InGaN/GaN quantum wells and InAlGaN layer shows very good agreement with the proposed theoretical approach.
Źródło:
Acta Physica Polonica A; 2016, 130, 5; 1209-1212
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badanie procesu transferu ładunku wzbudzanego światłem w organicznych ogniwach słonecznych za pomocą czasowo rozdzielczej fotoluminescencji i pobudzanego światłem elektronowego rezonansu spinowego
Detection of Photo-Induced Charge Transfer in Organic Solar Cells by Time-Resolved Photoluminescence and Light-Induced Electron Spin Reseonance
Autorzy:
Grankowska-Ciechanowicz, S.
Iwan, A.
Wołoś, A.
Korona, K. P.
Kamińska, M.
Powiązania:
https://bibliotekanauki.pl/articles/160166.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Elektrotechniki
Tematy:
transfer ładunku
organiczne ogniwa słoneczne
czasowo rozdzielcza fotoluminescencja
pobudzany światłem elektronowy rezonans spinowy
charge transfer
organic solar cells
TRPL
(L)ESR
Opis:
Organiczne ogniwa słoneczne są jednym z obiecujących sposobów przetwarzania energii słonecznej w elektryczną. Procesem mającym decydujący wpływ na ich działanie, jest transfer ładunku wzbudzany światłem. Techniki pomiarowe, które znalazły zastosowanie do bezpośredniej detekcji tego procesu, to czasowo rozdzielcza fotoluminescencja (TRPL – ang. time-resolved photoluminescence) i pobudzany światłem elektronowy rezonans spinowy (LESR – ang. light-induced electron spin resonance). Efektywny transfer ładunku, przy pomocy TRPL, rejestrowany jest jako wygaszanie luminescencji w wyniku przestrzennego rozseparowania ładunków przeciwnego znaku, a za pomocą LESR jako dwie linie pochodzące od dodatniego polaronu po stronie donora i ujemnego polarnu po stronie akceptora. W niniejszej pracy omówione zostaną wymienione techniki pomiarowe oraz ich zastosowanie do detekcji efektywnego transferu ładunku w organicznych ogniwach słonecznych.
The organic solar cells are considered as promising way to convert solar energy into electricity. A crucial step in their operations is a photo-induced charge transfer (CT). Techniques, which directly detect this phenomenon, are Time-Resolved Photoluminescence (TRPL) and Light-induced Electron Spin Resonance (LESR). Effective photo-induced CT results in electrons and holes separation and creation of positive and negative polarons. First process is registered by TRPL as luminescence quenching, second by LESR as two lines, one from positive, and another from negative polarons. In this article, both techniques will be described as well their application in effective CT detection.
Źródło:
Prace Instytutu Elektrotechniki; 2014, 264; 65-71
0032-6216
Pojawia się w:
Prace Instytutu Elektrotechniki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical and Electrical Studies of Graphene Deposited on GaN Nanowires
Autorzy:
Kierdaszuk, J.
Kaźmierczak, P.
Drabińska, A.
Wysmołek, A.
Korona, K.
Kamińska, M.
Pakuła, K.
Pasternak, I.
Krajewska, A.
Żytkiewicz, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1195433.pdf
Data publikacji:
2014-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.ue
72.10.Fk
78.67.Wj
72.80.Vp
Opis:
In this paper using scanning electron microscope, contactless microwave electronic transport and the Raman spectroscopy we studied the properties of graphene deposited on GaN nanowires and compared it with the graphene deposited on GaN epilayer. The Raman micro-mapping showed that nanowires locally change the strain and the concentration of carriers in graphene. Additionally we observed that nanowires increase the intensity of the Raman spectra by more than one order of magnitude.
Źródło:
Acta Physica Polonica A; 2014, 126, 5; 1087-1089
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Photoluminescence Dynamics of GaN/Si Nanowires
Autorzy:
Korona, K.
Zytkiewicz, Z.
Perkowska, P.
Borysiuk, J.
Binder, J.
Sobanska, M.
Klosek, K.
Powiązania:
https://bibliotekanauki.pl/articles/1403621.pdf
Data publikacji:
2012-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Cr
73.22.-f
78.47.jd
Opis:
In this work we present analysis of carriers dynamics in samples of GaN nanowires grown on silicon. The samples exhibit bright luminescence of bulk donor-bound excitons at 3.472 eV, surface defect-bound excitons at 3.450 eV (SDX) and a broad (0.05 eV) band centered at 3.47 eV caused probably by single free exciton and bi-exciton recombination. The SDX emission has long lifetime τ = 0.6 ns at 4 K and can be observed up to 50 K. At higher temperatures luminescence is dominated by free excitons. The broad excitonic band is best visible under high excitation, and reveals fast, non-exponential dynamics. We present mathematical model assuming exciton-exciton interaction leading to the Auger processes. The model includes $n^2$ (Langevin) term and describes well the non-exponential dynamics of the excitonic band.
Źródło:
Acta Physica Polonica A; 2012, 122, 6; 1001-1003
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anharmonic Optical Phonon Effects in ZnO Nanocrystals
Autorzy:
Khusnutdinov, S. V.
Dynowska, E.
Zaleszczyk, W.
Makhniy, V. P.
Wysmołek, A.
Korona, K. P.
Powiązania:
https://bibliotekanauki.pl/articles/2048106.pdf
Data publikacji:
2011-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.61.Ga
74.25.nd
63.20.kg
Opis:
Zinc oxide (ZnO) is a very promising material for optoelectrical devices operating at the short-wavelength end of the visible spectral range and at the near UV. The Raman scattering studies of ZnO heterolayers formed by isothermal annealing show sharp phonon lines. In addition to the A$\text{}_{1}$(TO), E$\text{}_{1}$(TO), E$\text{}_{2}^{H}$, and E$\text{}_{1}$(LO) one-phonon lines, we observed two-phonon lines identified as: E$\text{}_{2}^{H}$ - E$\text{}_{2}^{L}$, E$\text{}_{2}^{H}$ + E$\text{}_{2}^{L}$, and 2LO at 332, 541, and 1160 cm$\text{}^{-1}$, respectively (at room temperature). The identification of the E$\text{}_{2}^{H}$ - E$\text{}_{2}^{L}$ peak was confirmed by its thermal dependence. Temperature dependent measurements in the range 6-300 K show that the phonon frequencies decrease with temperature. The E$\text{}_{2}^{H}$ peak is at energy 54.44 meV (439.1 cm$\text{}^{-1}$), at 4 K and due to phonon-phonon anharmonic interaction, its energy decreases to 54.33 meV (438.2 cm$\text{}^{-1}$) at room temperature. The Grüneisen parameter found for this oscillation mode was γ$\text{}_{E}$ 2H = 1.1 at about 300 K. The intensity of the E$\text{}_{2}^{H}$ - E$\text{}_{2}^{L}$ peak increases strongly with temperature and this dependence can be described by the Bose-Einstein statistics with activation energy of 13.8 meV (nearly equal to the energy of the E$\text{}_{2}^{L}$ phonon).
Źródło:
Acta Physica Polonica A; 2011, 119, 5; 678-680
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transport of Photoexcited Electron-Hole Plasma in GaN/AlGaN Quantum Well
Autorzy:
Korona, K.
Caban, P.
Strupiński, W.
Powiązania:
https://bibliotekanauki.pl/articles/1791352.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.61.Ey
72.40.+w
Opis:
We report spatially resolved photocurrent measurements showing transport of excitation on long distances in plane of a 6 nm GaN/$Al_{0.1}Ga_{0.9}N$ quantum well. The strong field present in nitrides (due to large spontaneous and piezoelectric polarizations) leads to lower recombination rates of electrons and holes, so in the case of electron-hole pairs excited by light, relatively long-lived electron-hole plasma could be generated. In the case of the investigated quantum well, lifetime of few μs was expected. The thermal measurements showed that barriers were low enough, so all excited carriers could reach the electrode (thermal activation energy of 0.11 eV was found). The diffusion length for unbiased structure was about 40 μm. It was observed that the charge transport could be clearly accelerated by bias. In the biased quantum well, the transport range was of the order of 100 μm under both positive and negative bias. The reported effect of long transport range is very important for electronic devices made on the GaN/AlGaN structures.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 927-929
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
InGaN QW in External Electric Field Controlled by Pumping of 2D-Electron Gas
Autorzy:
Korona, K.
Drabińska, A.
Surowiecka, K.
Wołowiec, L.
Borysiuk, J.
Caban, P.
Strupiński, W.
Powiązania:
https://bibliotekanauki.pl/articles/1811946.pdf
Data publikacji:
2008-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.61.Ey
78.55.Cr
72.40.+w
Opis:
We present investigations of GaInN/GaN/AlGaN structure containing cavity designed so that the electric field inside it can be changed by illumination. Numerical calculations show that illumination can change carrier distributions and consequently change the field and potential. The electric field influences properties of a quantum well placed in the cavity. We confirmed experimentally that the electric field controlled by external bias or by optical pumping, can change energy and occupation of electronic states in the quantum well. The quantum well energy could be changed of about 80 meV by voltage and 15 meV by illumination.
Źródło:
Acta Physica Polonica A; 2008, 114, 5; 1179-1186
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:
Dynamics of Excitation Transfer Inside InAs/GaAs Quantum Dot System
Autorzy:
Korona, K. P.
Babiński, A.
Raymond, S.
Wasilewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2046919.pdf
Data publikacji:
2006-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.47.+p
72.20.Jv
78.67.Hc
78.55.Cr
Opis:
We present time-resolved photoluminescence investigations of InAs/GaAs structures containing quantum dots with the ground state at 1.43 eV. State filling effect and a Pauli blocking effect were clearly observed. These effects significantly influenced dynamics of excitation transfer from upper to lower state inside a dot leading to non-exponential dynamics. Numerical model based on nonlinear rate equations was proposed. The model described well the experimental data providing values of: lifetime of the ground state 0.53±0.03 ns, lifetime of excited state (when the ground state is full) 1.1±0.2 ns, and internal relaxation time (when the ground state is empty) 0.07±0.01 ns.
Źródło:
Acta Physica Polonica A; 2006, 110, 2; 219-224
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multiband GaN/AlGaN UV Photodetector
Autorzy:
Korona, K. P.
Drabińska, A.
Pakuła, K.
Baranowski, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/2046918.pdf
Data publikacji:
2006-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.40.+w
73.61.Ey
73.40.Kp
Opis:
We present optical and electrical measurements made on GaN/AlGaN photodetector structure capable to detect three UV ranges, tuned by external voltage. The highest band at energy of about 3.85 eV is nearly independent of bias applied to the Schottky contact. Photosensitivity of the second band at about 3.65 eV changes strongly with the bias. Signal in this range increases about 20 times when the bias changes from 0 V to -4 V. Photosensitivity of the third band (3.4 eV) appears for strong reverse bias (-3 V). Characteristics of the detector are in qualitative agreement with numerical model, however deep centers present in the AlGaN layers cause quantitative discrepancies. The concentration of defects of the order of 10$\text{}^{16}$ cm$\text{}^{-3}$ was estimated from current transients.
Źródło:
Acta Physica Polonica A; 2006, 110, 2; 211-217
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Potential and Carrier Distribution in AlGaN Superlattice
Autorzy:
Korona, K. P.
Pakuła, K.
Bożek, R.
Drabińska, A.
Surowiecka, K.
Stępniewski, R.
Zielińska-Rohozińska, E.
Baranowski, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/2043725.pdf
Data publikacji:
2005-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.40.+w
73.61.Ey
73.21.Cd
Opis:
Photocurrent spectroscopy and Kelvin force microscopy have been used in order to determine charge, field, and potential distributions in spontaneously grown superlattice. The spectra show that light can generate currents and potentials in both directions depending on photon energy. A numerical model made for superlattice of periodλ$\text{}_{SL}$ = 33 nm shows that electric field in superlattice oscillates coherently with Al content. The oscillations of electric field explain the different directions of photocurrent. The electric field can also separate electrons and holes, making carrier lifetimes longer and lowering excitation intensity threshold for occupation inversion.
Źródło:
Acta Physica Polonica A; 2005, 108, 4; 723-729
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Formation of Mn-Related Defect Band in InP
Autorzy:
Macieja, B.
Korona, K. P.
Piersa, M.
Witowski, A. M.
Wasik, D.
Wysmołek, A.
Strzelecka, G.
Hruban, A.
Surma, B.
Palczewska, M.
Kamińska, M.
Twardowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/2036033.pdf
Data publikacji:
2003-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Eq
72.20.Ee
72.20.Jv
Opis:
Electron paramagnetic resonance, optical absorption, luminescence and electrical studies of InP highly doped with Mn were performed. Electron paramagnetic resonance revealed presence of manganese in Mn$\text{}^{2+}$(d$\text{}^{5}$) configuration. In optical absorption, systematic reduction of InP band gap was observed with increase in Mn content. This was correlated with increase in photoionization-type absorption band starting at 0.2 eV. Time-resolved photoluminescence measurements showed decrease in photoexcited carrier lifetime and shortening of donor-acceptor pair recombination time with increase in Mn content. Moreover, photoluminescence band was shifted to lower energies, similarly to optical band gap. In electrical transport two mechanisms of conductivity were observed. Valence band transport dominated at higher temperatures, above 160 K, and activation energy of free-hole concentration was determined as about 0.20 eV. At lower temperatures hopping conductivity, clearly related to Mn defect band, was present. All these results were consistent with assumption of creation of Mn-related defect-band at 0.2 eV above InP valence band. It was found that Mn centers responsible for this band were in configurations of either d$\text{}^{5}$ or d$\text{}^{5}$ plus a hole localized about 7Å around corresponding Mn core.
Źródło:
Acta Physica Polonica A; 2003, 103, 6; 637-642
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Localization Effects in GaN/AlGaN Quantum Well - Photoluminescence Studies
Autorzy:
Chwalisz, B.
Wysmołek, A.
Bożek, R.
Korona, K. P.
Stępniewski, R.
Knap, W.
Pakuła, K.
Baranowski, J. M.
Grandjean, N.
Massies, J.
Prystawko, P.
Grzegory, I.
Powiązania:
https://bibliotekanauki.pl/articles/2036024.pdf
Data publikacji:
2003-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Cr
73.20.-r
73.21.-b
74.40.+k
Opis:
Exciton localization in GaN/AlGaN quantum well structures is studied by photoluminescence. An anomalous temperature behavior of the photoluminescence from the quantum well is observed. With increasing temperature the energy position of the excitonic emission line first decreases up to 20 K, then increases, reaching a maximum around 90 K, and then decreases again in the higher temperature range. The observed behavior is discussed in terms of localization at the interface potential fluctuations. It is argued that the temperature activated migration and subsequent release of the excitons from traps that occurs between 20 K and 90 K are responsible for the observed S-like shape of the energy dependence. The obtained results allow a direct characterization of the energy fluctuations present in GaN/AlGaN quantum wells grown by different techniques.
Źródło:
Acta Physica Polonica A; 2003, 103, 6; 573-578
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tuning of Spectral Sensitivity of AlGaN/GaN UV Detector
Autorzy:
Korona, K. P.
Drabińska, A.
Trajnerowicz, A.
Bożek, R.
Pakuła, K.
Baranowski, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/2036867.pdf
Data publikacji:
2003-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.40.Kp
73.50.Pz
78.40.Fy
Opis:
GaN/AlGaN photodetector that exhibits new interesting property is presented. Its spectral sensitivity depends upon bias voltage. Under positive or low negative bias the detector is sensitive mainly to the ultrafiolet radiation absorbed by AlGaN layer 3.7-3.8 eV. Under negative bias U$\text{}_{B}$ below -4 V, the detector is sensitive mainly to the radiation absorbed by GaN (3.4-3.6 eV). The effect can be explained based on numerical calculations of the electric field and potential profiles of this structure. The damping of GaN signal is attributed to activity of 2D electron gas formed on the GaN/AlGaN interface by spontaneous polarization. The reappearing of the signal is attributed to tunneling of holes through AlGaN, stimulated by a high electric field.
Źródło:
Acta Physica Polonica A; 2003, 103, 6; 675-681
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamics of Photoexcited Carriers in GaInAs/GaAs Quantum Dots
Autorzy:
Ilczuk, E.
Korona, K. P.
Babiński, A.
Kuhl, J.
Powiązania:
https://bibliotekanauki.pl/articles/2028722.pdf
Data publikacji:
2001-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.40.+w
78.47.+p
78.67.-n
Opis:
We present photocurrent and time-resolved photoluminescence investigations of AlGaAs/GaInAs/GaAs structures containing GaInAs/GaAs self-assembled quantum dots. The high electrical field in those devices significantly influences carrier dynamics. The photocurrent spectra show a double peak with maxima at 1.40 and 1.47 eV (at 80 K). These maxima are due to the GaInAs wetting layer (higher) and the quantum dots (lower). The photoluminescence spectra comprise weak excitonic luminescence from GaAs at 1.504 eV (at 80 K) and stronger and broad emission from the Ga$\text{}_{0.4}$In$\text{}_{0.6}$As quantum dots. At 300 K, the quantum dots emission has a lifetime of 1.1 ns and has a maximum at an energy of 1.38 eV. By analysis of both experiments, we can separate the influence of different radiative and nonradiative recombination processes. So, the tunneling rate: r$\text{}_{T}$=0.5 ns$\text{}^{-1}$ and the radiative recombination rate in the quantum dots: r$\text{}_{RQD}$=0.4 ns$\text{}^{-1}$ have been determined. The high tunneling probability (due to the influence of the built-in electric field) reveals that the tunneling effect is important for the recombination and transport processes in our structures.
Źródło:
Acta Physica Polonica A; 2001, 100, 3; 379-386
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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