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1.
Effective excitation cross section of erbium in amorphous hydrogenated silicon under optical pumping
M. S. Bresler O. B. Gusev P. E. Pak E. I. Terukov I. N. Yassievich 《Physics of the Solid State》2001,43(4):625-628
The effective excitation cross section of erbium embedded in an amorphous silicon matrix and the total lifetime of erbium ions in the excited state are determined by measuring the photoluminescence rise time of erbium ions under pulsed excitation of erbium-doped amorphous hydrogenated silicon. An analysis of the rate equations describing the excitation and deexcitation of erbium ions in a semiconducting matrix sheds light on the physical meaning of the effective excitation cross section. It is shown that measurement of the effective excitation cross section permits evaluation of the concentration of optically active erbium ions in the amorphous silicon matrix. 相似文献
2.
V. Yu. Timoshenko O. A. Shalygina M. G. Lisachenko D. M. Zhigunov S. A. Teterukov P. K. Kashkarov D. Kovalev M. Zacharias K. Imakita M. Fujii 《Physics of the Solid State》2005,47(1):121-124
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. 相似文献
3.
P. K. Kashkarov M. G. Lisachenko O. A. Shalygina V. Yu. Timoshenko B. V. Kamenev M. Schmidt J. Heitmann M. Zacharias 《Journal of Experimental and Theoretical Physics》2003,97(6):1123-1130
The spectra and kinetics of photoluminescence from multilayered structures of quasi-ordered silicon nanocrystals in a silica matrix were studied for undoped samples and samples doped with erbium. It was shown that the optical excitation energy of silicon nanocrystals could be effectively transferred to Er3+ ions, which was followed by luminescence at a wavelength of 1.5 µm. The effectiveness of energy transfer increased as the size of silicon nanocrystals decreased and the energy of exciting light quanta increased. The excitation of erbium luminescence in the structures was explained based on dipole-dipole interaction (the Förster mechanism) between excitons in silicon nanocrystals and Er3+ ions in silica surrounding them. 相似文献
4.
D. S. Korolev A. B. Kostyuk A. I. Belov A. N. Mikhaylov Yu. A. Dudin A. I. Bobrov N. V. Malekhonova D. A. Pavlov D. I. Tetelbaum 《Physics of the Solid State》2013,55(11):2361-2367
The photoluminescence spectra of erbium centers in SiO2 films with ion-synthesized silicon nanoclusters under nonresonant excitation were investigated. Erbium was introduced into thermal SiO2 films by ion implantation. The dependences of photoluminescence intensity on the dose, the order of ion implantation of Si and Er, the annealing temperature, and additional Ar+ and P+ ion irradiation regimes, i.e., factors determining the influence of radiation damage and doping on sensitization of erbium luminescence by silicon nanoclusters, were determined. It was found that the sensitization effect and its amplification due to doping with phosphorus are most pronounced under the conditions where nanoclusters are amorphous. The quenching of photoluminescence due to radiation damage in this case manifests itself to a lesser extent than for crystalline nanoclusters. The role of various factors in the observed regularities was discussed in the framework of the existing concepts of the mechanisms of light emission and energy exchange in the system of silicon nanoclusters and erbium centers. 相似文献
5.
B. A. Andreev Z. F. Krasil’nik V. P. Kuznetsov A. O. Soldatkin M. S. Bresler O. B. Gusev I. N. Yassievich 《Physics of the Solid State》2001,43(6):1012-1017
The photoluminescence of semiconducting structures Si: Er: O/Si grown by the molecular-beam epitaxy method is studied. The dependences of Er photoluminescence intensity on the intensity of pumping are measured at the liquid helium temperature. An analysis of the experimental results on the basis of the exciton model of excitation of Er ions in a crystalline silicon matrix reveals the significant role played by an alternative channel of free-exciton trapping (apart from the donor energy levels of erbium-oxygen complexes), as well as that played by the nonradiative channel in the recombination of excitons, bound to erbium donors, without the excitation of erbium. The ratio of the concentration of optically active centers of erbium luminescence to the total concentration of introduced erbium is estimated. 相似文献
6.
O. B. Gusev A. V. Ershov D. A. Grachev B. A. Andreev A. N. Yablonskiy 《Journal of Experimental and Theoretical Physics》2014,118(5):728-734
The effect of surface states of silicon nanocrystals embedded in silicon dioxide on the photoluminescent properties of the nanocrystals is reported. We have investigated the time-resolved and stationary photoluminescence of silicon nanocrystals in the matrix of silicon dioxide in the visible and infrared spectral ranges at 77 and 300 K. The structures containing silicon nanocrystals were prepared by the high-temperature annealing of multilayer SiO x /SiO2 films. The understanding of the experimental results on photoluminescence is underlain by a model of autolocalized states arising on surface Si-Si dimers. The emission of autocatalized excitons is found for the first time, and the energy level of the autolocalized states is determined. The effect of these states on the mechanism of the excitation and the photoluminescence properties of nanocrystals is discussed for a wide range of their dimensions. It is reliably shown that the cause of the known blue boundary of photoluminescence of silicon nanocrystals in the silicon dioxide matrix is the capture of free excitons on autolocalized surface states. 相似文献
7.
M. S. Bresler O. B. Gusev E. I. Terukov Yu. K. Undalov N. A. Selyuzhenok 《Physics of the Solid State》2008,50(9):1731-1735
The erbium photoluminescence decay kinetics at a wavelength of 1.54 μm in amorphous hydrogenated silicon films obtained at high oxygen concentrations in a magnetron gas discharge is investigated. Optically active erbium is found to exist both in the semiconducting matrix of amorphous silicon and in dielectric nanocrystals of erbium silicate, which are formed in this case. The concentration ratio of excited erbium in amorphous silicon and in the nanocrystals is determined, as well as the time of excitation transfer from erbium in amorphous silicon to erbium in the nanocrystals. The mechanism of erbium excitation in this heterogeneous system is considered. The external quantum yield of erbium photoluminescence measured at a wavelength of 1.54 μm and room temperature is found to be 0.3–0.4%. 相似文献
8.
9.
SnO2 thin films undoped and doped with antimony (Sb), erbium (Er) and Si nanocrystals (Si-nc) have been grown on silicon (Si) substrate using sol-gel method. Room-temperature photoluminescence (PL) measurement of undoped SnO2, under excitation at 280 nm, shows only one broad emission at 395 nm, which is related to oxygen vacancies. The PL of Er3+ ions was found to be enhanced after doping SnO2 with Sb and Si-nc. The excitation process of Er is studied and discussed. The calculation of cross-section suggests a sensitisation of Er PL by Si-nc. 相似文献
10.
A. Martucci M. De Nuntis A. Ribaudo M. Guglielmi S. Padovani F. Enrichi G. Mattei P. Mazzoldi C. Sada E. Trave G. Battaglin F. Gonella E. Borsella M. Falconieri M. Patrini J. Fick 《Applied Physics A: Materials Science & Processing》2005,80(3):557-563
Ag- and Er-doped glass films have been synthesized with a combined sol–gel and ion-exchange route. The introduction of silver as erbium sensitizer in the film was obtained by ion exchanging Er-doped SiO2–Al2O3–Na2O sol–gel films. The films were subsequently annealed under controlled atmosphere to induce the migration and aggregation of the metal ions. Films showed different Er3+ photoluminescence behaviors depending on silver concentration and aggregation state. The interaction between erbium ions and Ag centers has been investigated and enhancement of the excitation cross section due to the silver sensitizing effect has been demonstrated. The developed synthesis also allowed the realization of erbium-doped channel waveguides by a selective Na–Ag ion-exchange process . PACS 81.20.Fw; 78.55.-m; 42.82.Et 相似文献
11.
V. S. Kortov K. A. Sergeeva V. A. Pustovarov A. A. Rempel 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2017,11(4):727-731
The photoluminescence of Zn2SiO4:Mn2+ ceramics with a particle size of 120 ± 10 nm, which is excited in the range of 3.5–5.8 eV and subjected to synchrotron radiation with photon energies of up to 20 eV, is investigated. Nanoscale Zn2SiO4:Mn2+ ceramics possesses intense luminescence with a maximum of 2.34 eV, the position and half-width of the band are independent of the excitation energy. It is found that the photoluminescence at 2.34 eV decays nonexponentially upon ultraviolet excitation. In the case of nanoscale ceramics is irradiated by vacuum ultraviolet, an additional photoluminescence-excitation channel is likely to occur due to interaction of band states and intrinsic vacancy-like defects of the Zn2SiO4 matrix. 相似文献
12.
D. I. Tetelbaum A. N. Mikhaylov A. I. Belov V. K. Vasiliev A. I. Kovalev D. L. Wainshtein Y. Golan A. Osherov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2009,3(5):702-708
Luminescent and structural characteristics of SiO2 layers exposed to double implantation by Si+ and C+ ions in order to synthesize nanosized silicon carbide inclusions have been investigated by the photoluminescence, electron spin resonance, transmission electron microscopy, and electron spectroscopy methods. It is shown that the irradiation of SiO2 layers containing preliminary synthesized silicon nanocrystals by carbon ions is accompanied by quenching the nanocrystal-related photoluminescence at 700–750 nm and by the enhancement of light emission from oxygen-deficient centers in oxide in the range of 350–700 nm. Subsequent annealing at 1000 or 1100°C results in the healing of defects and, correspondingly, in the weakening of the related photoluminescence peaks and also recovers in part the photoluminescence of silicon nanocrystals if the carbon dose is less than the silicon dose and results in the intensive white luminescence if the carbon and silicon doses are equal. This luminescence is characterized by three bands at ~400, ~500, and ~625 nm, which are related to the SiC, C, and Si phase inclusions, respectively. The presence of these phases has been confirmed by electron spectroscopy, the carbon precipitates have the sp 3 bond hybridization. The nanosized amorphous inclusions in the Si+ + C+ implanted and annealed SiO2 layer have been revealed by high-resolution transmission electron microscopy. 相似文献
13.
J. Castañeda-Contreras M.A. Meneses-Nava O. Barbosa-García R. Chiu-Zárate M.V. Félix R. Rodriguez 《Journal of luminescence》2010,130(12):2356-2361
The intensity of erbium up-conversion luminescence could be limited by a saturation effect due to increased pump power. We studied the luminescence saturation of the 550 nm emission on erbium-doped, SiO2–TiO2 sol–gel powders under pulsed excitation at 979 and 1532 nm. From the latter, the up-converted luminescence intensity decreased with increasing excitation power, whereas no saturation was observed at 979 nm excitation. We proposed that the saturation effect is determined by the pump power, the erbium content and the lifetime of the corresponding first excited states at different pumping schemes. 相似文献
14.
N. V. Znamenskiy T. G. Yukina Yu. V. Malyukin P. N. Zhmurin Yu. N. Velikhov 《Laser Physics》2007,17(4):491-495
For the fist time in Y2SiO5:Pr3+ nanocrystals, the ordered stage in the 1 D 2 luminescence decay curves for Pr3+ ions has been observed at anomalously low doped ion concentration (0.5 at %). This effect is caused by preferred location of the activator ions in the near-surface layer of the nanocrystal that provides the relaxation of elastic tension arising due to the difference of ionic radii of Pr3+ and Y3+ ions. Concentration quenching of Pr3+ luminescence is caused by the cooperative cross-relaxation. 相似文献
15.
K. Dohnalová K. K?sová J. Valenta M. Gallart J.L. Rehspringer 《Journal of luminescence》2006,121(2):259-262
We report on light emission from silicon nanocrystals (Si-nc) in a laser cavity. Using modified electrochemical etching of Si wafers we prepare Si-nc with blue-shifted photoluminescence spectrum down to 580-620 nm, embedded at high-volume fractions in a SiO2-based solid matrix. We insert this active medium into an optically pumped resonator. Since our samples are only partially homogeneous, we cannot use external mirrors in order to achieve optical feedback: we induced optically an internal distributed cavity by intense, spatially periodical excitation. Mode selection was simulated by a simplified theoretical model, based on an approach of multiple reflections. In the framework of the model we discuss the experimentally observed spectral emission changes induced by the distributed cavity. 相似文献
16.
E. S. Demidov M. V. Karzanova A. N. Mikhaylov D. I. Tetelbaum A. I. Belov D. S. Korolev D. A. Pavlov A. I. Bobrov O. N. Gorshkov N. E. Demidova Yu. I. Chigirinskii 《Physics of the Solid State》2014,56(3):631-634
Using transmission electron microscopy and elemental analysis, it has been shown that tungsten telluride glass (TTG) containing erbium and ytterbium as impurities penetrates into pores of porous silicon (PS) when melted in vacuum at 500°C. It has been found that the intensity of photoluminescence (PL) of erbium at the wavelength of 1.54 μm in PS: TTG layers increases by a factor of up to 5 in the layers irradiated by P+ and Ar+ ions. This is assigned to ion mixing which favors interaction among the Er ions and PS-embedded Si nanocrystals initiating sensitization of the PL, as well as to broadening of the glass-impregnated PS region. Implantation of the lighter Ne+ ions affects only weakly the PL of erbium ions. 相似文献
17.
D. I. Tetelbaum O. N. Gorshkov A. P. Kasatkin A. N. Mikhaylov A. I. Belov D. M. Gaponova S. V. Morozov 《Physics of the Solid State》2005,47(1):13-17
The photoluminescence intensity (PLI) related to Si nanocrystals in a SiO2: nc-Si system synthesized by ion implantation is studied experimentally and theoretically as a function of the Si+ ion dose at various annealing temperatures Tann (1000–1200°C). The dose corresponding to the maximum PLI is found to decrease with increasing Tann. These data are explained in terms of a model taking into account the coalescence of neighboring nanocrystals and the dependence of the probability of radiative recombination of quantum dots on their size. It is found that, when silicon oxide is grown in a wet atmosphere, the photoluminescence spectrum contains an additional band (near 850 nm), which is related to shells around the nanocrystals. This band weakens abrupily after high-temperature annealing in an oxidizing atmosphere (air). 相似文献
18.
Luisa Sciortino Fabrizio Messina Gianpiero Buscarino Simonpietro Agnello Marco Cannas Franco M. Gelardi 《Journal of nanoparticle research》2017,19(6):228
We describe the simple fabrication of SiO2 sol-gel monoliths embedding highly luminescent carbon nanodots (CDs) sensitive to metal ions. The pristine CDs we synthesize display an intense dual emission consisting in two fluorescence bands in the green and violet region, and we demonstrate that this photoluminescence is substantially unchanged when the dots are incorporated in the SiO2 matrix. The emission of these CDs is quenched by interactions with Cu2+ ions, which can be used to detect these ions with a detection limit of 1 μM. The chromophores remain accessible to diffusing Cu2+ ions even after embedding CDs in the sol-gel monolith, where their detection capabilities are preserved. Such a result provides the proof-of-principle of a new sensing scheme, where CDs are exploited as active sensing centers of metal transition ions within a solid-state device. The different interaction mechanisms of CDs with copper, in liquid and solid phase, are analyzed in detail and discussed in terms of different accessibility of their chromophores when the dots are incorporated in the SiO2 matrix. 相似文献
19.
K. A. Subbotin Yu. N. Osipova D. A. Lis V. A. Smirnov E. V. Zharikov I. A. Shcherbakov 《Optics and Spectroscopy》2017,123(1):49-55
Concentration series of disordered scheelitelike Yb:NaGd(MoO4)2 and Yb:NaLa(MoO4)2 single crystals are grown by the Czochralski method. The actual concentrations of Yb3+ ions in the crystals are determined by optical-absorption spectroscopy. The luminescence of Yb3+ ions in these crystals in the region of 1 μm is studied under UV and IR excitation. In the case of UV excitation, this luminescence appears as a result of nonradiative excited state energy transfer from donor centers of unknown nature to ytterbium. The character of the concentration dependence of Yb3+ luminescence indicates that the energy transfer at high Yb concentrations occurs with active participation of a cooperative mechanism, according to which the excitation energy of one donor center is transferred simultaneously to two Yb3+ ions. In other words, the quantum yield of this transfer exceeds unity, which can be used to increase the efficiency of crystalline silicon (c-Si) solar cells. 相似文献
20.
Javier del-Castillo V. D. Rodríguez A. C. Yanes J. Méndez-Ramos 《Journal of nanoparticle research》2008,10(3):499-506
Undoped and Er3+-doped glass–ceramics of composition (100−x)SiO2–xSnO2, with x = 5 or 10 and with 0.4 or 0.8 mol% of Er3+ ions, were synthesised by thermal treatment of precursor sol–gel glasses. Structural studies were developed by X-Ray Diffraction.
Wide band gap SnO2 semiconductor quantum-dots embedded in the insulator SiO2 glass are obtained. The mean radius of the SnO2 nanocrystals, ranging from 2 to 3.2 nm, is comparable to the exciton Bohr radius. The luminescence properties have been analysed
as a function of sample composition and thermal treatment. The results show that Er3+ ions are partially partitioned into the nanocrystalline phase. An efficient UV excitation of the Er3+ ions by energy transfer from the SnO2 nanocrystal host is observed. The Er3+ ions located in the SnO2 nanocrystals are selectively excited by this energy transfer mechanism. On the other hand, emission from the Er3+ ions remaining in the silica glassy phase is obtained by direct excitation of these ions. 相似文献