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N. A. Sobolev - One of the best experts on this subject based on the ideXlab platform.
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Silicon LEDs with room-temperature dislocatIon-related luminescence, fabricated by Erbium Ion implantatIon and chemical-vapor depositIon of polycrystalline silicon layers heavily doped with boron and phosphorus
Semiconductors, 2007Co-Authors: N. A. Sobolev, A. M. Emel’yanov, V. V. Zabrodskiĭ, N. V. Zabrodskaya, V. L. Sukhanov, Elena I. ShekAbstract:Light-emitting diodes (LEDs) have been fabricated in which optically active centers are formed by implantatIon of Erbium Ions into silicon and subsequent high-temperature annealing in an oxidizing atmosphere and the p-n junctIon and the ohmic contact are formed by chemical vapor depositIon of polycrystalline silicon layers doped with boron and phosphorus, respectively. The luminescent properties of the LEDs have been studied. Use of polycrystalline layers makes it possible to eliminate the losses in the bulk of the light-emitting Si:Er layer. These losses are inevitable if the conventIonal Ion implantatIon and diffusIon methods are employed. At 80 K, the variatIon of electroluminescence spectra in the spectral range of the dislocatIon-related luminescence with the drive current is well described if the spectrum is decomposed into three Gaussian components whose peak positIons and widths are current-independent and amplitudes linearly increase with the current. At 300 K, a single peak is observed in the spectral range of the dislocatIon-related luminescence at ∼1.6 μm.
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correlatIon between luminescent properties and structure organizatIon in algan gan superlattices annealed after Erbium Ion implantatIon
Technical Physics, 2006Co-Authors: E. E. Baranov, N. A. Sobolev, W. V. Lundin, V. N. Petrov, V. I. Sakharov, I. T. Serenkov, A. N. Titkov, Elena I. Shek, A M Emelyanov, N. M. ShmidtAbstract:The evolutIon of the structure organizatIon of MOCVD-grown AlGaN/GaN superlattices subjected to Erbium Ion implantatIon with an energy of 1 MeV and dose of 3 × 1015 cm−2 and subsequent annealing is correlated with their photoluminescent properties. The structure organizatIon is quantitatively estimated using parameter Δ (degree of violatIon of local symmetry), which is found via multifractal analysis of surface morphology patterns obtained with atomic force microscopy. It is shown that the implantatIon not only causes Ga segregatIon on the surface, but also changes the structure organizatIon, which shows up in the finer grain structure compared with the starting one and disordering, as well as in an increase in Δ. As the annealing temperature rises from 700 to 800°C, Δ declines, indicating that the structure organizatIon is improved, and the intensity of the dominating photoluminescence peak due to Er3+ Ions (1.542 μm) grows. With a further increase in the annealing temperature to 1050°C, the structure organizatIon degrades, domains get larger, voids 100–200 nm deep form, and the photoluminescence intensity drops. The formatIon of voids during high-temperature annealing is also substantiated by data for 230-keV proton scattering. It is thus established that the improvement of the superlattice structure organizatIon activates Erbium and causes the Erbium-Ion-related luminescence intensity to grow.
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CorrelatIon between luminescent properties and structure organizatIon in AlGaN/GaN superlattices annealed after Erbium Ion implantatIon
Technical Physics, 2006Co-Authors: E. E. Baranov, N. A. Sobolev, A. M. Emel’yanov, W. V. Lundin, V. N. Petrov, V. I. Sakharov, I. T. Serenkov, A. N. Titkov, Elena I. Shek, N. M. ShmidtAbstract:The evolutIon of the structure organizatIon of MOCVD-grown AlGaN/GaN superlattices subjected to Erbium Ion implantatIon with an energy of 1 MeV and dose of 3 × 1015 cm−2 and subsequent annealing is correlated with their photoluminescent properties. The structure organizatIon is quantitatively estimated using parameter Δ (degree of violatIon of local symmetry), which is found via multifractal analysis of surface morphology patterns obtained with atomic force microscopy. It is shown that the implantatIon not only causes Ga segregatIon on the surface, but also changes the structure organizatIon, which shows up in the finer grain structure compared with the starting one and disordering, as well as in an increase in Δ. As the annealing temperature rises from 700 to 800°C, Δ declines, indicating that the structure organizatIon is improved, and the intensity of the dominating photoluminescence peak due to Er3+ Ions (1.542 μm) grows. With a further increase in the annealing temperature to 1050°C, the structure organizatIon degrades, domains get larger, voids 100–200 nm deep form, and the photoluminescence intensity drops. The formatIon of voids during high-temperature annealing is also substantiated by data for 230-keV proton scattering. It is thus established that the improvement of the superlattice structure organizatIon activates Erbium and causes the Erbium-Ion-related luminescence intensity to grow.
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Effect of the annealing temperature on Erbium Ion electroluminescence in Si:(Er,O) diodes with (111) substrate orientatIon
Semiconductors, 2001Co-Authors: N. A. Sobolev, A. M. Emel’yanov, Yu. A. NikolaevAbstract:The influence of the temperature of secondary annealing, stimulating the formatIon of optically and electrically active centers, on the Erbium Ion electroluminescence (EL) at λ≈1.54 µm in (111) Si:(Er,O) diodes has been studied. The diodes were fabricated by the implantatIon of 2.0 and 1.6 MeV Erbium Ions at doses of 3×1014 cm−2 and oxygen Ions (0.28 and 0.22 MeV, 3×1015 cm−2). At room temperature, the EL intensity in the breakdown mode grows with the annealing temperature increasing from 700 to 950°C. At annealing temperatures of 975–1100°C, no Erbium EL is observed in the breakdown mode owing to the formatIon of microplasmas. The intensity of the injectIon EL at 80 K decreases with the annealing temperature increasing from 700 to 1100°C.
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influence of Erbium Ion implantatIon dose on characteristics of 111 si er o light emitting diodes operating in p n junctIon breakdown mode
Semiconductors, 2000Co-Authors: N. A. Sobolev, A M Emelyanov, Yu. A. NikolaevAbstract:Characteristics of Si:(Er, O) light-emitting diodes (LEDs) fabricated by Ion implantatIon on single-crystal (111) Si substrates and operating under the conditIons of avalanche or tunneling breakdown of the p-n junctIon were studied. The Er3+ electroluminescence (EL) intensity depends nonmonotonically on the concentratIon of implanted rare-earth Ions. An increase in the Er3+ Ion EL intensity with temperature is observed in some tunneling diodes.
Yu V Timoshenko - One of the best experts on this subject based on the ideXlab platform.
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specific features of Erbium Ion photoluminescence in structures with amorphous and crystalline silicon nanoclusters in silica matrix
Semiconductors, 2010Co-Authors: Sergey A Dyakov, D M Zhigunov, Yu V TimoshenkoAbstract:Photoluminescence properties of the structures of amorphous and crystalline silicon nanoclusters with average sizes no larger than 4 nm in an Erbium-doped silicon dioxide matrix were studied. It was found that the photoluminescence lifetime of Er3+ Ions at a wavelength of 1.5 μm decreases from 5.7 to 2.0 ms and from 3.5 to 1.5 ms in samples with amorphous nanoclusters and with nanocrystals, respectively, as the Er3+ concentratIon increases from 1019 to 1021 cm−3. The decrease in the Erbium photoluminescence lifetime with the Ion concentratIon is attributed to the effects of concentratIon-related quenching and residual implantatIon-induced defects. The difference between lifetimes for samples with amorphous and crystalline nanoclusters is interpreted as the effect of different probabilities of energy back transfer from Er3+ Ions to the solid-state matrix in the structures under consideratIon.
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observatIon of the populatIon inversIon of Erbium Ion states in si si1 xgex er si structures under optical excitatIon
Optical Materials, 2006Co-Authors: M V Stepikhova, O A Shalygina, D M Zhigunov, L V Krasilnikova, Z F Krasilnik, V G Shengurov, Yu V Chalkov, Yu V TimoshenkoAbstract:Abstract In this work we present the results of theoretical analysis and experimental studies carried out for Si/Si1−xGex:Er/Si structures considered as the candidates for a laser realizatIon. Analysis of the electromagnetic modes distributIon and parameters of Si/Si1−xGex:Er/Si waveguides enabling strong localizatIon of the optical modes in the active Si1−xGex:Er layers is given. The Si/Si1−xGex:Er/Si structures in questIon were grown by the method of sublimatIon MBE in germane gas atmosphere. The capability of such a method for producing effectively emitting Si/Si1−xGex:Er/Si structures has been demonstrated. The photoluminescence intensity of the structures produced is comparable with that determined for the uniformly doped Si:Er layers with the external quantum efficiency ∼0.4%. We show the possibility to achieve the populatIon inversIon of Er3+ Ion states in Si/Si1−xGex:Er/Si structures under optical excitatIon. The populatIon inversIon of Er3+ states in these structures sets in at the pump density of ∼0.2 W/cm2 and reaches its maximal value at ∼4 W/cm2, where the concentratIon of Er3+ Ions being inversely populated amounts to ∼80% of the total concentratIon of optically active Er Ions.
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Erbium Ion luminescence of silicon nanocrystal layers in a silicon dioxide matrix measured under strong optical excitatIon
Physics of the Solid State, 2005Co-Authors: Yu V Timoshenko, P K Kashkarov, M G Lisachenko, O A Shalygina, Margit Zacharias, S. A. Teterukov, D M Zhigunov, D Kovalev, Kenji Imakita, Minoru FujiiAbstract:The photoluminescence (PL) spectra and kinetics of Erbium-doped layers of silicon nanocrystals dispersed in a silicon dioxide matrix (nc-Si/SiO2) are studied. It was found that optical excitatIon of nc-Si can be transferred with a high efficiency to Er3+ Ions present in the surrounding oxide. The efficiency of energy transfer increases with increasing pumping photon energy and intensity. The process of Er3+ excitatIon is shown to compete successfully with nonradiative recombinatIon in the nc-Si/SiO2 structures. The Er3+ PL lifetime was found to decrease under intense optical pumping, which implies the establishment of inverse populatIon in the Er3+ system. The results obtained demonstrate the very high potential of Erbium-doped nc-Si/SiO2 structures when used as active media for optical amplifiers and light-emitting devices operating at a wavelength of 1.5 μm.
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highly efficient sensitizing of Erbium Ion luminescence in size controlled nanocrystalline si sio2 superlattice structures
Applied Physics Letters, 2004Co-Authors: Yu V Timoshenko, P K Kashkarov, B V Kamenev, M G Lisachenko, O A Shalygina, Michael W I Schmidt, J Heitmann, Margit ZachariasAbstract:Comparative studies of photoluminescence (PL) of undoped and Er-doped size-controlled nanocrystalline Si/SiO2 superlattice structures show that the optical excitatIon of Si nanocrystals can be completely transferred to the Er3+ Ions in surrounding SiO2, resulting in a strong PL line at 1.5 μm. The PL yield of the Er-doped structure increases for higher photon energy of excitatIon and for smaller nanocrystal sizes. This highly efficient sensitizing of the Er-related PL is explained by a strong coupling between excitons confined in Si nanocrystals and neighboring Er3+ Ions in their upper excited states.
F. J. Pérez - One of the best experts on this subject based on the ideXlab platform.
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effects of yttrium and Erbium Ion implantatIon on the aisi 304 stainless steel passive layer
Thin Solid Films, 2002Co-Authors: F Pedraza, M.j. Cristóbal, M. P. Hierro, E Roman, F. J. PérezAbstract:In this work, the response of AISI 304 stainless steel after having been implanted with 1017 Ions/cm2 doses of Y and Er at an acceleratIon potential of 150 keV is examined. ComputatIonal estimates of the implanted profile have been performed using the PROFILE code. The nature of the outermost surface of the steel, i.e. the passive layer and onwards is studied by means of Auger Electron Spectroscopy as well as X-Ray Photoelectron Spectroscopy techniques, supported by thermodynamics calculatIons. It is shown that the incorporatIon of both reactive elements in the steel surface brings about different changes in the nature of their respective passive layers. Both implanted Ions induce oxidatIon of the base material to a certain extent, probably due to the implantatIon process itself giving rise to Cr2O3 and FeO and/or Fe·OH species, together with different RE oxides as well as Y(OH)3.
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CorrosIon ProtectIon of Low-Nickel Austenitic Stainless Steel by Yttrium and Erbium-Ion ImplantatIon Against Isothermal OxidatIon
Oxidation of Metals, 2000Co-Authors: F. J. Pérez, M.j. Cristóbal, G. Arnau, M. P. Hierro, Julien BotellaAbstract:The beneficial effect of Ion-implanted yttrium and Erbium on the oxidatIon behavior of low-nickel austenitic stainless steel (LNiSS) at 973 K has been investigated up to 500 hr of oxidatIon test in air. The resulting oxide scales were examined by a wide range of experimental techniques, including SEM/EDS, XRD, and EPMA. The results indicate that both reactive elements have similar effects. The most significant effects have been to significantly reduce the corrosIon rate and to improve the oxide scale adhesIon. It is concluded that Ion implantatIon is a powerful tool as surface-modificatIon process introducing reactive elements in the top surface.
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effect of yttrium and Erbium Ion implantatIon on the oxidatIon behaviour of the aisi 304 austenitic steel
Surface & Coatings Technology, 2000Co-Authors: F. J. Pérez, M.j. Cristóbal, G. Arnau, M. P. Hierro, F Pedraza, T P MerinoAbstract:Abstract The beneficial effect of the additIon of yttrium and Erbium by Ion implantatIon on the oxidatIon behaviour of AISI 304 stainless steel at 1173 K has been investigated. Isothermal oxidatIon tests have been conducted for up to 500 h. The effect of ‘rare earth elements’ (REE) have been studied previously in order to enhance the oxidatIon behaviour of different alloys. The results show that yttrium and Erbium have similar effects, reducing the rate of continuing scale growth and inhibiting scale failure processes. It is concluded in this study, that both reactive elements inhibit the growth of the poorly protective and adherent oxides rich in iron and chromium, which help the spalled behaviour, together with a smaller oxide grain size.
Margit Zacharias - One of the best experts on this subject based on the ideXlab platform.
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Erbium Ion luminescence of silicon nanocrystal layers in a silicon dioxide matrix measured under strong optical excitatIon
Physics of the Solid State, 2005Co-Authors: Yu V Timoshenko, P K Kashkarov, M G Lisachenko, O A Shalygina, Margit Zacharias, S. A. Teterukov, D M Zhigunov, D Kovalev, Kenji Imakita, Minoru FujiiAbstract:The photoluminescence (PL) spectra and kinetics of Erbium-doped layers of silicon nanocrystals dispersed in a silicon dioxide matrix (nc-Si/SiO2) are studied. It was found that optical excitatIon of nc-Si can be transferred with a high efficiency to Er3+ Ions present in the surrounding oxide. The efficiency of energy transfer increases with increasing pumping photon energy and intensity. The process of Er3+ excitatIon is shown to compete successfully with nonradiative recombinatIon in the nc-Si/SiO2 structures. The Er3+ PL lifetime was found to decrease under intense optical pumping, which implies the establishment of inverse populatIon in the Er3+ system. The results obtained demonstrate the very high potential of Erbium-doped nc-Si/SiO2 structures when used as active media for optical amplifiers and light-emitting devices operating at a wavelength of 1.5 μm.
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highly efficient sensitizing of Erbium Ion luminescence in size controlled nanocrystalline si sio2 superlattice structures
Applied Physics Letters, 2004Co-Authors: Yu V Timoshenko, P K Kashkarov, B V Kamenev, M G Lisachenko, O A Shalygina, Michael W I Schmidt, J Heitmann, Margit ZachariasAbstract:Comparative studies of photoluminescence (PL) of undoped and Er-doped size-controlled nanocrystalline Si/SiO2 superlattice structures show that the optical excitatIon of Si nanocrystals can be completely transferred to the Er3+ Ions in surrounding SiO2, resulting in a strong PL line at 1.5 μm. The PL yield of the Er-doped structure increases for higher photon energy of excitatIon and for smaller nanocrystal sizes. This highly efficient sensitizing of the Er-related PL is explained by a strong coupling between excitons confined in Si nanocrystals and neighboring Er3+ Ions in their upper excited states.
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high efficiency Erbium Ion luminescence in silicon nanocrystal systems
Physics of the Solid State, 2004Co-Authors: P K Kashkarov, B V Kamenev, M G Lisachenko, O A Shalygina, Yu V Timoshenk, Michael W I Schmidt, J Heitmann, Margit ZachariasAbstract:The photoluminescence spectra and kinetics of both Erbium-doped and undoped multilayer struc- tures of quasi-ordered silicon nanocrystals in a silicon dioxide matrix were studied. It was shown that the opti- cal excitatIon energy of silicon nanocrystals 2-3 nm in size can be practically completely transferred to Er 3+ Ions in the oxide surrounding the nanocrystals, with its subsequent radiatIon at 1.5 μ m. Possible reasons for the high excitatIon efficiency of the Er 3+ Ions are discussed, and the conclusIon is drawn that the Forster mech- anism is dominant in the energy transfer processes occurring in these structures. © 2004 MAIK "Nauka/Inter- periodica".
O A Shalygina - One of the best experts on this subject based on the ideXlab platform.
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observatIon of the populatIon inversIon of Erbium Ion states in si si1 xgex er si structures under optical excitatIon
Optical Materials, 2006Co-Authors: M V Stepikhova, O A Shalygina, D M Zhigunov, L V Krasilnikova, Z F Krasilnik, V G Shengurov, Yu V Chalkov, Yu V TimoshenkoAbstract:Abstract In this work we present the results of theoretical analysis and experimental studies carried out for Si/Si1−xGex:Er/Si structures considered as the candidates for a laser realizatIon. Analysis of the electromagnetic modes distributIon and parameters of Si/Si1−xGex:Er/Si waveguides enabling strong localizatIon of the optical modes in the active Si1−xGex:Er layers is given. The Si/Si1−xGex:Er/Si structures in questIon were grown by the method of sublimatIon MBE in germane gas atmosphere. The capability of such a method for producing effectively emitting Si/Si1−xGex:Er/Si structures has been demonstrated. The photoluminescence intensity of the structures produced is comparable with that determined for the uniformly doped Si:Er layers with the external quantum efficiency ∼0.4%. We show the possibility to achieve the populatIon inversIon of Er3+ Ion states in Si/Si1−xGex:Er/Si structures under optical excitatIon. The populatIon inversIon of Er3+ states in these structures sets in at the pump density of ∼0.2 W/cm2 and reaches its maximal value at ∼4 W/cm2, where the concentratIon of Er3+ Ions being inversely populated amounts to ∼80% of the total concentratIon of optically active Er Ions.
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Effect of nonuniform permittivity of a solid-state matrix on the spectral width of Erbium Ion luminescence
Physics of the Solid State, 2005Co-Authors: S. A. Teterukov, M G Lisachenko, O A Shalygina, Denis M. Zhigunov, V. Yu. Timoshenko, Pavel K. KashkarovAbstract:The Stark splitting of the energy levels of Er3+ Ions implanted in a structure made up of alternating layers of silicon dioxide and quasi-ordered silicon nanocrystals is calculated. The level splitting is caused by the electric field of the image charges induced at the interfaces between layers with different permittivities. The splitting was established to increase as the contrast in permittivity between the silicon dioxide and silicon nanocrystal layers increases, as well as when the Erbium Ions approach the layer interface. The results obtained offer an adequate explanatIon of the experimentally observed additIonal broadening of the Erbium photoluminescence band (0.8 eV) with increasing characteristic size of the silicon nanocrystals.
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Erbium Ion luminescence of silicon nanocrystal layers in a silicon dioxide matrix measured under strong optical excitatIon
Physics of the Solid State, 2005Co-Authors: Yu V Timoshenko, P K Kashkarov, M G Lisachenko, O A Shalygina, Margit Zacharias, S. A. Teterukov, D M Zhigunov, D Kovalev, Kenji Imakita, Minoru FujiiAbstract:The photoluminescence (PL) spectra and kinetics of Erbium-doped layers of silicon nanocrystals dispersed in a silicon dioxide matrix (nc-Si/SiO2) are studied. It was found that optical excitatIon of nc-Si can be transferred with a high efficiency to Er3+ Ions present in the surrounding oxide. The efficiency of energy transfer increases with increasing pumping photon energy and intensity. The process of Er3+ excitatIon is shown to compete successfully with nonradiative recombinatIon in the nc-Si/SiO2 structures. The Er3+ PL lifetime was found to decrease under intense optical pumping, which implies the establishment of inverse populatIon in the Er3+ system. The results obtained demonstrate the very high potential of Erbium-doped nc-Si/SiO2 structures when used as active media for optical amplifiers and light-emitting devices operating at a wavelength of 1.5 μm.
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highly efficient sensitizing of Erbium Ion luminescence in size controlled nanocrystalline si sio2 superlattice structures
Applied Physics Letters, 2004Co-Authors: Yu V Timoshenko, P K Kashkarov, B V Kamenev, M G Lisachenko, O A Shalygina, Michael W I Schmidt, J Heitmann, Margit ZachariasAbstract:Comparative studies of photoluminescence (PL) of undoped and Er-doped size-controlled nanocrystalline Si/SiO2 superlattice structures show that the optical excitatIon of Si nanocrystals can be completely transferred to the Er3+ Ions in surrounding SiO2, resulting in a strong PL line at 1.5 μm. The PL yield of the Er-doped structure increases for higher photon energy of excitatIon and for smaller nanocrystal sizes. This highly efficient sensitizing of the Er-related PL is explained by a strong coupling between excitons confined in Si nanocrystals and neighboring Er3+ Ions in their upper excited states.
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high efficiency Erbium Ion luminescence in silicon nanocrystal systems
Physics of the Solid State, 2004Co-Authors: P K Kashkarov, B V Kamenev, M G Lisachenko, O A Shalygina, Yu V Timoshenk, Michael W I Schmidt, J Heitmann, Margit ZachariasAbstract:The photoluminescence spectra and kinetics of both Erbium-doped and undoped multilayer struc- tures of quasi-ordered silicon nanocrystals in a silicon dioxide matrix were studied. It was shown that the opti- cal excitatIon energy of silicon nanocrystals 2-3 nm in size can be practically completely transferred to Er 3+ Ions in the oxide surrounding the nanocrystals, with its subsequent radiatIon at 1.5 μ m. Possible reasons for the high excitatIon efficiency of the Er 3+ Ions are discussed, and the conclusIon is drawn that the Forster mech- anism is dominant in the energy transfer processes occurring in these structures. © 2004 MAIK "Nauka/Inter- periodica".