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Tytuł:
Factors Affecting Luminescence Intensity of Lanthanide Ions. Analytical Applications of Lanthanide Luminescence in Solution
Autorzy:
Lis, S.
Powiązania:
https://bibliotekanauki.pl/articles/1929808.pdf
Data publikacji:
1993-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.-m
Opis:
The factors which efficiently reduce nonradiative energy degradation of the lanthanide ion fluorescence are described. The most sensitive systems in spectrofluorimetric determination of trace amounts of lanthanide ions based on the complex formation, intramolecular energy transfer and mixed complexes with synergic agents in a liquid phase, are presented. Detection limits of highly sensitive systems obtained with the use of conventional and laser-excited spectrofluorimetry for Sm(III), Eu(III), Tb(III) and Dy(III) are compared.
Źródło:
Acta Physica Polonica A; 1993, 84, 5; 1003-1010
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative Spectroscopic Study of the Dy$\text{}^{3+}$ Doped Double Chloride and Double Fluoride Crystals for Telecommunication Amplifiers and IR Lasers
Autorzy:
Tkachuk, A.
Ivanova, S.
Isaenko, L.
Yelisseyev, A.
Payne, Steve
Solarz, R.
Nostrand, M.
Page, R.
Payne, Stephen
Powiązania:
https://bibliotekanauki.pl/articles/1995823.pdf
Data publikacji:
1999-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.-m
Opis:
In this work we studied spectroscopic characteristics of potassium-lead double-chloride, and lithium-yttrium double-fluoride crystals doped with dysprosium. Objects of research were KPb$\text{}_{2}$Cl$\text{}_{5}$:Dy$\text{}^{3+}$, and LiYF$\text{}_{4}$ (YLF):Dy$\text{}^{3+}$ crystals grown by the Bridgman-Stockbarger technique. We obtained the effective distribution coefficients K$\text{}_{Dy}$=0.95 for LiYF$\text{}_{4}$ :Dy$\text{}^{3+}$, and K$\text{}_{Dy}$=1 for KPb$\text{}_{2}$Cl$\text{}_{5}$:Dy$\text{}^{3+}$. Optical spectra were studied, intensity parameters were determined by the Judd-Ofelt method, and radiative probabilities and branching ratio were calculated. The conclusion was made that the studied crystals can be considered as promising new active media for laser diode pumped solid state lasers. The YLF:Dy$\text{}^{3+}$ crystals are perspective for laser action near 3 mm, and the KPb$\text{}_{2}$Cl$\text{}_{5}$ :Dy$\text{}^{3+}$ for multiwavelength IR lasers, and for 1.3 mm laser diode pumped telecommunication amplifiers.
Źródło:
Acta Physica Polonica A; 1999, 95, 3; 381-394
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Luminescence of $CdWO_4$:Tb,Li Crystals under Synchrotron Excitation at 10 K
Autorzy:
Novosad, S.
Kostyk, L.
Novosad, I.
Luchechko, A.
Stryganyuk, G.
Powiązania:
https://bibliotekanauki.pl/articles/1418270.pdf
Data publikacji:
2012-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.-m
Opis:
The luminescent properties of $CdWO_4$:Tb,Li crystals have been investigated at 10 K in the region 4-25 eV using synchrotron excitation. It is shown that besides the intrinsic matrix luminescence the number emission lines due to electron f-f-transitions in $Tb^{3+}$ ions are efficiently excited at near-edge region of the fundamental absorption ($E_\text{exc}$ = 4.1 eV). The weak recombination luminescence of terbium impurity on the background of intensive matrix luminescence is observed under excitation in the region of fundamental absorption ($E_\text{exc}$ = 5.4 and 13.8 eV). It is shown that the luminescence spectrum of the matrix is a superposition of three elementary bands 2.07, 2.47, and 2.73 eV. The nature of emission bands is discussed.
Źródło:
Acta Physica Polonica A; 2012, 122, 4; 717-720
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of Free Exciton Capture Cross Section of Si:Al by Photoluminescence
Autorzy:
Schramm, G.
Powiązania:
https://bibliotekanauki.pl/articles/1887812.pdf
Data publikacji:
1991-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.-m
Opis:
The free excitons capture rate and capture cross-section of the neutral Al atom in silicon were determined at 4.2 K. The obtained values are of the same order of magnitude as reported values of other shallow dopants.
Źródło:
Acta Physica Polonica A; 1991, 79, 6; 869-872
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Infrared-to-Visible Upconversion in Erbium Pentaphosphate
Autorzy:
Kaczmarek, F.
Balicki, M.
Karolczak, J.
Powiązania:
https://bibliotekanauki.pl/articles/1929357.pdf
Data publikacji:
1993-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.-m
78.55.Hx
Opis:
Infrared-to-visible upconversion has been observed by many authors in a variety of rare-earth-doped crystals. This paper reports the study of the up-conversion found in stoichiometric erbium pentaphosphate, ErP$\text{}_{5}$O$\text{}_{1}$4. Strong green fluorescence was observed upon pumping the crystal with a cw diode laser at a wavelength of about 800 nm.
Źródło:
Acta Physica Polonica A; 1993, 83, 6; 831-836
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Blue Photoluminescent Band in ZnS Crystals
Autorzy:
Liem, N. Q.
Quang, V. X.
Thanh, D. X.
Powiązania:
https://bibliotekanauki.pl/articles/1931824.pdf
Data publikacji:
1994-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.-m
78.55.Et
Opis:
The zinc sulphide crystals as-grown and heat treated in different atmospheres, have been studied by photoluminescence technique. A blue emission band (IB) peaking at 2.91 eV has been identified in the mentioned crystals. Parameters of the IB band such as peak energy, half width of spectrum, lifetime of photoluminescence as well as a superlinearly excitation intensity dependence of the luminescence have been determined. A model of the IB transition is proposed to explain the properties and features of IB luminescence.
Źródło:
Acta Physica Polonica A; 1994, 86, 6; 979-985
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Preheating Temperature on Microstructure and Optical Properties of ZnO Thin Films Prepared by Sol-Gel Spin Coating Technique
Autorzy:
Ji, Qiang-min
Wang, Ya-li
Gao, Xiao-yong
Gao, Hui
Zhai, Yao-fei
Powiązania:
https://bibliotekanauki.pl/articles/1398971.pdf
Data publikacji:
2016-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Et
78.55.-m
Opis:
Highly-oriented ZnO thin films prepared by using low-cost technique such as sol-gel technique are of much importance to ZnO-based white light-emitting diodes. The chose of proper preheating temperature in sol-gel technique is still critical for highly-oriented ZnO thin film so far. The mechanisms for the preheating in the formation of ZnO thin film and for the reactions involved in the sol solution have not been clearly stated yet. Thus, in this work, the highly-oriented ZnO thin films were prepared on glass substrates by using sol-gel spin-coating technique. The sol solution was prepared by using the two-step method rather than usual one-step method, which facilitates the understanding of the mechanism for the reactions involved in the sol solution. The effect of the preheating temperature on the microstructure and the optical properties of the films were in particular investigated. The mechanisms for the preheating in the formation of the films and for the reactions involved in the sol solution prepared by the two-step method were also proposed in terms of the experimental results. The preheating not only enhances the volatilization of the solvent 2-methoxyethanol and the decomposition of the residual organic species, but also results into the formation of small number of ZnO particles. The preheating temperature of 300°C is most favorable for the highly-oriented ZnO thin film. Increasing the preheating temperature results into the blue shift of the absorption edges of the films. This can be explained by using the quantum-size effect. The photoluminescence spectra of the films show an UV emission at the near-band edge and a broad green-yellow emission at 470-620 nm. The former is closely related to the excitons, while the latter is to the intrinsic defect species in the film.
Źródło:
Acta Physica Polonica A; 2016, 129, 6; 1191-1196
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of the IB Emission Band in Al-Doped ZnS Crystals
Autorzy:
Liem, N. Q.
Quang, V. X.
Thanh, D. X.
Powiązania:
https://bibliotekanauki.pl/articles/1945436.pdf
Data publikacji:
1996-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.-m
78.55.Et
Opis:
Time-resolved luminescence spectroscopy and thermal lensing techniques are applied to the study of deep centre photoluminescence and absorption in Al-doped ZnS crystals, which are as-grown or heat treated in different Zn rich or S rich atmospheres. A blue emission band peaking at 2.89 eV has been identified as IB band in all the mentioned crystals. Parameters of the IB band at 300 K, 77 K and 10 K such as peak energy, half width of spectrum, radiative lifetime have been determined. The IB band exhibits some special properties such as a shift neither with increasing delay time nor with excitation intensity nor with sample temperatures as well as a superlinearly excitation intensity dependence of the luminescence. An energy diagram and electronic transitions in the IB centre are presented to explain the experimental results.
Źródło:
Acta Physica Polonica A; 1996, 89, 5-6; 717-726
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy Transfer, Fluorescence and Scintillation Processes in Cerium-Doped RE$\text{}^{3+}$ AlO$\text{}_{3}$ Fast Scintillators
Autorzy:
Mares, J. A.
Nikl, M.
Powiązania:
https://bibliotekanauki.pl/articles/1945462.pdf
Data publikacji:
1996-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.-m
78.60.-b
Opis:
Modern applications of scintillators in medical imaging of human body (Positron Emission Tomography - PET scanning, γ-cameras and other X-ray tomographies) require improved or even quite new scintillators which should be characterized by (i) fast response, (ii) high density and (iii) high light yield. At present time new scintillating crystals are investigated, mainly those having perovskite lattice structure of the formula RE$\text{}^{3+}$ AlO$\text{}_{3}$:Ce where RE $\text{}^{3+}$ = Y$\text{}^{3+}$, Gd$\text{}^{3+}$ and Lu$\text{}^{3+}$. Here, we will present the newest data with summarising properties of these types of scintillators including the mixed ones. Energy transfer processes between Ce$\text{}^{3+}$ main centres and Ce$\text{}^{3+}$ multisites are discussed together with their mechanisms including processes between Ce $\text{}^{3+}$ and Gd$\text{}^{3+}$ ions. Finally, the characteristic properties of scintillating crystals based on perovskite structure are reviewed.
Źródło:
Acta Physica Polonica A; 1996, 90, 1; 45-54
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of N$\text{}_{3}^{-}$ Ions on Chemiluminescence of the Eu(II)/Eu(III)-H$\text{}_{2}$O$\text{}_{2}$ System
Autorzy:
Elbanowski, M.
Staninski, K.
Kaczmarek, M.
Lis, S.
Powiązania:
https://bibliotekanauki.pl/articles/1945476.pdf
Data publikacji:
1996-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.60.Ps
78.55.-m
Opis:
The basic system of chemiluminescence investigations of relevant biological and inorganic compounds consists of Eu(II)/Eu(III) - H$\text{}_{2}$O$\text{}_{2}$. In these studies the increase in Eu(III) ion emission intensity usually results from an effective complexation reaction. In the present study, the N$\text{}_{3}^{-}$ ions are used as a ligand. The increase in the chemiluminescence intensity of the Eu(III) ion, the pH influence (in the range of 4.5-7.5) on the chemiluminescence intensity of the Eu(III) ion, as well as the quenching of the $\text{}^{5}$D$\text{}_{0}$ excited state of the Eu(III) ion are observed due to N$\text{}_{3}^{-}$ complexation. Taking into account the well-known Fenton system [Fe(II)/Fe(III) - H$\text{}_{2}$O$\text{}_{2}$], containing additionally the N$\text{}_{3}^{-}$, Eu(III) or Sm(III) ions, we found that the Eu(III) or Sm(III) ions were excited as a result of energy transfer process. A mechanism of the studied reactions is proposed.
Źródło:
Acta Physica Polonica A; 1996, 90, 1; 101-108
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Competition of Radiation Processes in 6H-SiC Observed by Luminescence
Autorzy:
Wysmołek, A.
Mroziński, P.
Dwiliński, R.
Vlaskina, S.
Kamińska, M.
Powiązania:
https://bibliotekanauki.pl/articles/1873137.pdf
Data publikacji:
1995-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.-m
78.60.Kn
Opis:
We report on the results of photoluminescence and thermoluminescence measurements of various 6H-SiC crystals. At low temperature in all n-type samples two bands with maxima at 2.7 eV (blue) and 1.8 eV (orange) were detected. In the p-type material only blue band was observed. The measurements performed at a broad range of temperatures showed totally different behaviour of photoluminescence intensity of both bands. The presented results could be explained in the model assuming well established donor-acceptor pair recombination for the blue band emission and the conduction band - deep defect transition for the orange band. The proposed model was confirmed by thermoluminescence measurements of the orange band which showed peaks at 30 K, 80 K, 100 K, 150 K attributed to ionization of subsequent shallow donor levels.
Źródło:
Acta Physica Polonica A; 1995, 87, 2; 437-440
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural and Optical Properties of Hydrothermally Synthesized ZnO and $Zn_{0.99}O:Eu^{3+}$ Powders
Autorzy:
Park, K.
Hakeem, D.
Kim, J.
Kim, Y.
Kim, S.
Powiązania:
https://bibliotekanauki.pl/articles/1398243.pdf
Data publikacji:
2018-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.-m
78.55.Hx
78.55.Et
Opis:
The structural and optical properties of the ZnO and $Zn_{0.99}O:Eu^{3+}$ powders synthesized by the hydrothermal method at two different temperatures (150°C and 250°C) were studied. The ZnO and $Zn_{0.99}O:0.01Eu^{3+}$ powders synthesized at 150 and 250°C showed rod- and flower-like morphologies, respectively. The as-synthesized and annealed ZnO and $Zn_{0.99}O:0.01Eu^{3+}$ powders formed the wurtzite crystal structure and P6₃mc space group. The crystallite size of the as-synthesized and annealed ZnO powders increased by the incorporation of $Eu^{3+}. The photoluminescence properties of annealed $Zn_{0.99}O:0.01Eu^{3+}$ powders were substantially improved by controlling the synthesis temperature. The annealed $Zn_{0.99}O:0.01Eu^{3+}$ powders synthesized at 250°C displayed much stronger emission intensity than those at 150°C.
Źródło:
Acta Physica Polonica A; 2018, 133, 4; 902-906
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and Luminescent Properties of $Eu^{3+}$ Doped Crystalline Diphosphate $Na_2ZnP_2O_7$
Autorzy:
Guerbous, L.
Gacem, L.
Powiązania:
https://bibliotekanauki.pl/articles/1418919.pdf
Data publikacji:
2012-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.20.-e
78.55.-m
78.55.Hx
Opis:
Undoped and $Eu^{3+}$-doped disodium zinc diphosphate $Na_2ZnP_2O_7$ (NZPO) single crystals are grown by the Czochralski method. X-ray diffraction, Fourier transform infrared and Raman techniques were used to check the crystallographic structure. Excitation and emission spectra were measured at room temperature and studied. The $Eu^{3+}$ ions occupy a non-centrosymmetric site with different coordination number. Very efficient energy transfer from $O-Eu^{3+}$ band state to $Eu^{3+}$ excited energy levels is highlighted.
Źródło:
Acta Physica Polonica A; 2012, 122, 3; 535-538
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Implantation of Rare-Earth Atoms into Si and III-V Compounds
Autorzy:
Kozanecki, A.
Langer, J. M.
Peaker, A. R.
Powiązania:
https://bibliotekanauki.pl/articles/1924312.pdf
Data publikacji:
1993-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.80.Jh
78.55.-m
Opis:
Most recent results on doping of Si and semiconductors by the implantation of rare-earth atoms are reviewed. It is shown that up to the concentration of about 1018 cm' clustering and precipitation can be avoided. Post-implantation annealing leads not only to a decrease in radiation damage, but in some cases also to migration of rare-earth implants. The results of the rare earth lattice location by the Rutherford backscattering measurements are also reported.
Źródło:
Acta Physica Polonica A; 1993, 83, 1; 59-70
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Photoluminescence Studies of Aluminum Nitride Nanowires
Autorzy:
Yang, J.
Na, H.
Kim, H.
Kebede, M.
Choi, R.
Jeong, J.
Lee, C.
Powiązania:
https://bibliotekanauki.pl/articles/1505466.pdf
Data publikacji:
2011-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.07.-b
78.55.-m
Opis:
We report the production of AlN nanowires by the thermal heating method, for exploring their photoluminescence properties. The room-temperature photoluminescence properties were investigated with different annealing environment. While broad emissions with peaks at around 2.45 and 2.95 eV were obtained from both unannealed and annealed samples, the additional 2.1 eV peak was found from the annealed samples. We have suggested the possible emission mechanisms based on the assumption that both 2.45 eV peak and 2.1 eV peak are ascribed to the nitrogen vacancies. Annealing in N_2 environment exhibited lower intensities of 2.45 eV peak and 2.1 eV peak in comparison to those in Ar environment, presumably due to the suppression of nitrogen vacancies.
Źródło:
Acta Physica Polonica A; 2011, 119, 2; 125-127
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, Structure, Photoluminescence, and Raman Spectrum of Indium Oxide Nanowires
Autorzy:
Kim, H.
Na, H.
Yang, J.
Lee,, C.
Powiązania:
https://bibliotekanauki.pl/articles/1505485.pdf
Data publikacji:
2011-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.07.-b
78.55.-m
Opis:
Production of indium oxide $(In_2O_3)$ whiskers at a very low temperature of 650°C was reported. The synthetic route was comprised of a thermal heating process of a mixture of In and Mg powders. We have investigated the structural properties of the as-synthesized nanowires by using X-ray diffraction and scanning electron microscopy. The product consisted of one-dimensional nanowires, with a crystalline cubic structure of $In_2O_3$. The photoluminescence measurement with the Gaussian fitting exhibited visible light emission bands centered at 2.1 eV and 2.8 eV. The peaks of the Raman spectrum were indexed to the modes being associated with cubic $In_2O_3$.
Źródło:
Acta Physica Polonica A; 2011, 119, 2; 143-145
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Photoluminescence and Double-Crystal X-Ray Study of InGaAs/InP: Effect of Rare Earth (Dysprosium) Addition During Liquid Phase Epitaxial Growth
Autorzy:
Pödör, B.
Csontos, L.
Somogyi, K.
Vignaud, D.
Powiązania:
https://bibliotekanauki.pl/articles/1876215.pdf
Data publikacji:
1995-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.-m
72.80.Ey
Opis:
High purity In$\text{}_{0.53}$Ga$\text{}_{0.47}$As layers were grown on semi-insulating InP:Fe substrates by liquid phase epitaxy by adding small amounts of dysprosium (rare earth) to the melt. Hall effect and photoluminescence measurements showed that the addition of Dy strongly reduced the carrier and residual donor concentration, with a concurrent shift of the excitonic luminescence toward higher energies. The observed effects are ascribed to the gettering of residual donor impurities in the melt by Dy, as well as to the effects of possible incorporation of Dy into the grown layers.
Źródło:
Acta Physica Polonica A; 1995, 87, 2; 465-468
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
$SiO_x$ Nanowires Produced on Molybdenum-Coated Si Substrates
Autorzy:
Kim, H.
Lee, J.
Yang, J.
Powiązania:
https://bibliotekanauki.pl/articles/1813396.pdf
Data publikacji:
2008-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.07.-b
78.55.-m
Opis:
We synthesized $SiO_x$ nanowires with diameters of 30-140 nm, for the first time by the simple heating of the Mo-coated Si substrates. X-ray diffraction, selected area electron diffraction, and energy-dispersive X-ray spectroscopy indicated that the nanowires were in an amorphous state, comprising Si and O only. Fitting the photoluminescence spectrum with Gaussian functions revealed that the nanowires exhibited significant photoluminescence intensities near blue and green light regions. We extensively discussed the possible growth mechanism of $SiO_x$ nanowires.
Źródło:
Acta Physica Polonica A; 2008, 113, 3; 1017-1020
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Catalyst-Free Growth of Magnesium Oxide Whiskers and Their Characteristics
Autorzy:
Kim, H.
Kong, M.
Yang, J.
Powiązania:
https://bibliotekanauki.pl/articles/1813397.pdf
Data publikacji:
2008-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.07.-b
78.55.-m
Opis:
This study reports the production of magnesium oxide (MgO) whiskers on silicon (Si) substrates by the thermal heating of $MgB_2$ powders. We investigated the structural properties of the as-synthesized whiskers by using X-ray diffraction, transmission electron microscopy, selected area electron diffraction, and scanning electron microscopy. The product consisted of one-dimensional whiskers with a square cross-section. The whiskers had a single-crystalline cubic structure of MgO. The photoluminescence measurement with the Gaussian fitting exhibited visible light emission bands centered at 2.39 eV and 2.91 eV. We proposed the growth of MgO whiskers to follow the vapor-solid mechanism.
Źródło:
Acta Physica Polonica A; 2008, 113, 3; 1021-1024
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental Study of Optical Transitions in Be-Doped GaAs/AlAs Multiple Quantum Wells
Autorzy:
Kundrotas, J.
Čerškus, A.
Ašmontas, S.
Valušis, G.
Sherliker, B.
Halsall, M.
Harrison, P.
Steer, M.
Powiązania:
https://bibliotekanauki.pl/articles/1178273.pdf
Data publikacji:
2005-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.-y
78.55.-m
Opis:
We present a photoluminescence study of optical transitions in Be acceptor-doped GaAs/AlAs multiple quantum wells at room and liquid nitrogen temperatures. We investigate excitonic spectra and reveal acceptor-impurity induced effects in multiple quantum wells having different width.
Źródło:
Acta Physica Polonica A; 2005, 107, 2; 245-249
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lattice Location of Rare Earth Ions in Semiconductors and Their Optical Activity
Autorzy:
Kozanecki, A.
Powiązania:
https://bibliotekanauki.pl/articles/1929781.pdf
Data publikacji:
1993-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.80.Ih
78.55.-m
Opis:
Lattice location experiments performed on Yb- and Er-doped III-V semiconducting compounds using Rutherford backscattering and channeling have been reviewed. It has been shown that Yb atoms locate substitutionally in InP and InP-based ternary alloys, while in gallium compounds no substitutional fraction of Yb could be detected. An intense intra-4f-shell luminescence of Yb$\text{}^{3+}$ has been observed in In compounds. The photoluminescence spectra of Yb$\text{}^{3+}$ reflect local alloy disorder in InPAs and GaInP, suggesting that the Yb atoms are tetrahedrally coordinated. No Yb-related emission could be observed in gallium compounds, except a weak Yb$\text{}^{3+}$ photoluminescence in GaP. An evidence has been presented that Er atoms introduced into III-V compounds locate predominantly at interstitial positions. In GaAs they move into tetrahedral lattice sites as a result of thermal annealing at temperatures higher than 600°C. The location of Er atoms at substitutional positions is accompanied with the disappearance of the intra-4f-shell luminescence of Er$\text{}^{3+}$. The reasons of the observed correlation of luminescence properties and positions of Er and Yb atoms in zincblende lattices are discussed.
Źródło:
Acta Physica Polonica A; 1993, 84, 5; 881-888
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Impact Ionization of Shallow Donors on Luminescence in GaAs
Autorzy:
Wysmołek, A.
Łusakowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1932094.pdf
Data publikacji:
1995-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.-m
72.20.Ht
Opis:
Luminescence spectra of n-type molecular beam epitaxial layer and semi-insulating liquid encapsulated Czochralski grown bulk GaAs were measured at liquid helium temperature for zero electric field and for fields which caused impact ionization of shallow donors. Application of the electric field caused a decrease in the luminescence intensity and a broadening of all observed structures. It was found that the electric field changed the luminescence spectrum of the n-type material in a different way than it did in the case of the semi-insulating one. For the n-type sample, an intensity of excitonic lines decreased much more than that of donor-acceptor lines when the electric field grew. A contrary was observed for the semi-insulating sample. An explanation of the result is proposed which takes into account an influence of ionised impurity scattering and localization in fluctuations of the electrostatic potential on the luminescence process.
Źródło:
Acta Physica Polonica A; 1995, 87, 1; 261-264
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Highly Compensated GaAs Crystal Obtained by Molecular CO Doping
Autorzy:
Bożek, R.
Korona, K. P.
Nowak, G.
Wasik, D.
Słupiński, T.
Kaczor, P.
Powiązania:
https://bibliotekanauki.pl/articles/1929707.pdf
Data publikacji:
1993-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.-i
78.55.-m
78.20.Jq
Opis:
GaAs:C crystal was grown by liquid encapsulated Czochralski technique with large partial pressure of CO in ambient atmosphere p$\text{}_{CO}$/p$\text{}_{tot}$ = 0.2 and investigated using near and infrared absorption, photoluminescence, photoconductivity, photo-induced current transient spectroscopy and photo-Hall measurements. High resistivity of the crystal was found in electrical measurements (10$\text{}^{7}$ Ω cm, the Fermi level at 0.67 eV below conduction band at 300 K). Local vibrational mode revealed increased concentration of carbon acceptor and presence of oxygen related complexes. Photoluminescence spectra were dominated by two bands with peak energies at 1.49 eV and 0.8 eV. The near band gap emission shifts with excitation intensity up to 4 meV/decade. In photocurrent spectrum a strong photoionization band with E = 0.55 eV is observed.
Źródło:
Acta Physica Polonica A; 1993, 84, 4; 669-672
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Near-Band-Edge Photoluminescence from Very High Quality Hexagonal ZnO Bulk Crystals
Autorzy:
Lieu, N. T. T.
Dat, D. H.
Liem, N. Q.
Powiązania:
https://bibliotekanauki.pl/articles/2035657.pdf
Data publikacji:
2003-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.-y
78.55.-m
78.55.Et
Opis:
The near-band-edge photoluminescence spectra of very high quality hexagonal ZnO single crystals in the temperature range between 9 and 305 K were measured. Based on the energetic positions and the evolutions of well-resolved photoluminescence lines with temperature and with excitation power density we interpret the observed photoluminescence lines as resulting from recombination of the free-exciton, bound-exciton, biexciton, inelastic exciton-exciton collision and electron-hole plasma.
Źródło:
Acta Physica Polonica A; 2003, 103, 1; 67-75
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Photoluminescence Kinetics of YAG Crystals Activated with Ce, and Ce and Mg
Autorzy:
Barzowska, J.
Kubicki, A.
Grinberg, M.
Kaczmarek, S.
Łuczyński, Z.
Wojtowicz, A. J.
Koepke, Cz.
Powiązania:
https://bibliotekanauki.pl/articles/1995826.pdf
Data publikacji:
1999-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.-i
78.47.+p
78.55.-m
Opis:
A basic spectroscopic measurements of luminescence, absorption, luminescence excitation spectra and emission kinetic measurements on YAG crystals activated with cerium and magnesium are presented. We report that the Ce$\text{}^{3+}$ luminescence decay constant, at 65 ns, is independent of Ce concentrations (from 0.05 to 0.2%) and that it does not change with the presence or absence of the Mg co-dopant. Nevertheless, we find that under pulsed laser excitation at 290 nm the rise time in Ce luminescence time profiles is effectively shorter in the Mg co-doped samples.
Źródło:
Acta Physica Polonica A; 1999, 95, 3; 395-402
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 92

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