共查询到20条相似文献,搜索用时 31 毫秒
1.
V. B. Shmagin D. Yu. Remizov Z. F. Krasil’nik V. P. Kuznetsov V. N. Shabanov L. V. Krasil’nikova D. I. Kryzhkov M. N. Drozdov 《Physics of the Solid State》2004,46(1):109-112
A series of Si: Er/Si light-emitting diode structures with a smoothly varying p-n junction breakdown mechanism, grown through sublimation molecular-beam epitaxy, is used to investigate the effect of the breakdown mechanism on the electroluminescence of the structures. The maximal intensity and excitation efficiency of room-temperature Er3+ ion electroluminescence are shown to be attained in diode structures with a mixed breakdown mechanism. 相似文献
2.
K. V. Ivanovskikh V. A. Pustovarov B. V. Shul’gin M. Kirm 《Physics of the Solid State》2005,47(8):1446-1449
Time-resolved excitation and emission spectra of SrF2: Er3+ upon selective excitation with synchrotron radiation in the VUV and ultrasoft x-ray ranges at T = 8 K were studied. The VUV luminescence of SrF2: Er3+ derives from high-energy interconfiguration 4f105d-4f11 transitions in the Er3+ ion. The VUV emission spectrum revealed, in addition to the 164.5-nm band (millisecond-range kinetics), a band at 146.4 nm (with a decay time of less than 600 ps). The formation of excitation spectra for the f-f and f-d transitions in the Er3+ ion is discussed. 相似文献
3.
V. N. Makhov T. V. Uvarova M. Kirm S. Vielhauer 《Bulletin of the Lebedev Physics Institute》2016,43(12):348-351
Thermal quenching of interconfigurational 5d-4f luminescence of Er3+ and Tm3+ ions in BaY2F8 crystals is studied in the temperature range of 330–790 K. The quenching temperatures are ~575 and ~550 K for Er3+ and Tm3+, respectively. It is shown that quenching of 5d-4f luminescence of Tm3+ ions is caused by thermally stimulated ionization of 5d electrons to the conduction band. 相似文献
4.
The absorption spectra of the Er3+ ions embedded in the AlN matrix have been investigated. The admixture of erbium was introduced in bulk AlN crystals by diffusion. The absorption lines, which are associated with the intraconfigurational electronic f–f-transitions from the ground 4 I 15/2-state to the levels of ion Er3+ excited states have been observed in the spectral range of 370–700 nm. The transitions to the state levels 4 F 9/2, 2 H 11/2, 4 F 7/2, 4 F 5/2, 2 H 9/2, and 4 G 11/2 have been investigated in detail at the temperature T = 2 K. The number of the observed lines for these transitions coincides with the theoretically possible one for the electronic f–f-transitions in the ions Er3+, which are in the crystal field with the symmetry below cubic. The narrowness of the observed lines and their number convincingly testify the replacement of preferably one regular crystalline position by erbium ions. The implementation of Er3+ in the Al3+ position with the local symmetry C 3v appears the most probable. The energy positions of the levels of excited states for the investigated transitions have been determined. The diagram of the Er3+ ion energy levels in the AlN crystals has been built. 相似文献
5.
A. P. Skvortsov V. A. Trepakov S. Kapphan A. Dejneka L. Jastrabik 《Physics of the Solid State》2009,51(7):1470-1472
The first results of the study of optical absorption spectra of KTaO3: Er3+ crystals are presented. In the 350–660-nm region, lines are observed deriving from intraconfigurational electronic transitions from the 4 I 15/2 ground state to levels of the 4 F 9/2, 4 S 3/2, 2 H 11/2, 4 F 7/2, 4 F 5/2(4 F 3/2), 2 G 9/2, and 4 G 11/2 excited states of the Er3+ ions. A comprehensive study of transitions to the 4 F 9/2, 4 S 3/2, 2 H 11/2, and 4 F 7/2 levels at 77 K is carried out. The number of lines observed for the above transitions fits the theoretically possible number for ?-? electronic transitions in Er3+ ions in the cubic crystal field. In the case of a differently charged substituted ion, this situation occurs only under nonlocal impurity charge compensation. The energies of the excited state levels for the transitions under study are determined. 相似文献
6.
Yu. K. Voron’ko A. V. Malov K. N. Nishchev P. A. Ryabochkina A. A. Sobol S. N. Ushakov 《Optics and Spectroscopy》2007,102(5):722-727
Based on the analysis of the absorption spectra of Er-doped calcium-niobium-gallium garnet (Er:CNGG) crystals according to the Judd-Ofelt theory, the intensity parameters for these crystals are determined to be Θ2 = 3.43 × 10?20 cm2 Θ4 = 1.20 × 10?20 cm2, and Θ6 = 0.58 × 10?20 cm2. The parameters found are compared with the intensity parameters for other laser oxide crystals. Using these intensity parameters, the probabilities of radiative transitions between the energy levels of Er3+ ions in CNGG crystals and the luminescence branching ratios βJJ’ are calculated. From the measured lifetime of the 4 I 11/2 level of Er3+ ions (τ = 626 μs) and the probability of the radiative transition from this level (A = 192 s?1), it is found that about 88% of the excitation energy in the Er:CNGG crystals is nonradiatively transferred from the 4 I 11/2 to the 4 I 13/2 level. It is suggested that an increase in the oscillator strength and in the line strength of the 4 I 15/2 → 2 H 11/2 transition of Er3+ in CNGG crystals, as well as an increase in the intensity parameter Θ2 with respect to the corresponding parameters for other garnet crystals are caused by the existence in CNGG crystals of Er3+ centers with the environment symmetry lower than D 2. 相似文献
7.
Vacuum ultraviolet luminescence of Er3+ ions in LiYF4 and BaY2F8 crystals has been investigated. It is revealed that under excitation by 193 nm radiation from an ArF excimer laser the interconfigurational 5d–4f radiative transitions in Er3+ ions are observed. It is shown that from the LiYF4:Er crystal only the spin-forbidden luminescence (λ = 165 nm) is detected, whereas both the spin-forbidden (λ = 169 nm) and spin-allowed (λ = 160.5 nm) components are observed from the BaY2F8:Er crystal. 相似文献
8.
Na0.4Y0.6F2.2:Er3+ (NYF:Er3+) crystals with an Er concentration up to 15% were grown by the Bridgman-Stockbarger method. The luminescence kinetics was investigated for a series of NYF:Er3+ crystals (0.5–15% Er), as well as the concentration and temperature quenching of the luminescence from radiative Er levels upon selective laser excitation. It is shown that the luminescence from the 4S3/2 level is quenched significantly with increasing temperature and concentration. The luminescence from the 4G11/2, 2G(H)9/2, 4F9/2, and 4I9/2 levels is quenched mainly due to nonradiative multiphonon transitions. The concentration quenching of the luminescence from the 4I11/2 and 4I13/2 levels was not observed. Possible schemes of the self-quenching of excited levels of erbium are considered and the microparameters and macrorates of self-quenching are estimated by model quantum-mechanical calculation. Based on the comparison of the calculated and experimental self-quenching rates, the most probable mechanisms and schemes of self-quenching are determined. The self-quenching of the 4S3/2 level of erbium was investigated experimentally and theoretically. Good agreement is obtained between the experimental and the calculated kinetic curves and the dependences of the self-quenching rates on Er concentration. It is concluded that NYF:Er3+ crystals are promising as active media for tunable lasers with laser diode pumping. 相似文献
9.
Ph. V. Demekhin I. D. Petrov B. M. Lagutin V. L. Sukhorukov A. Neogi P. Yeates E. T. Kennedy M. W. D. Mansfield J. T. Costello 《Optics and Spectroscopy》2007,102(2):149-158
The photoionization cross sections for the 4p shell of ions of the Kr isoelectronic sequence Rb+, Sr2+, and Y3+ are calculated. The configuration interaction theory and the perturbation theory are used to describe the many-electron effects. The relativistic effects are taken into account in the Pauli-Fock approximation. The calculated resonance structure of photoionization cross sections for the 4p shell in the region below the 4s threshold associated with the autoionization of the 4s-np singly excited states and the 4p4p-nln′l′ doubly excited states reproduces the results of recent measurements of total photoabsorption cross sections for the Rb+, Sr2+, and Y3+ ions. It is found that, as the nuclear charge in the isoelectronic sequence increases, the ratio between the direct and correlation parts of amplitudes of the 4s-(n/?)p transition changes and, as the consequence, the minimum of the photoionization cross section of the 4s shell shifts from the continuous spectrum to the region of states of discrete spectrum. This accounts for the strong changes in the shape of the 4s-np resonances in the photoionization cross sections for the 4p shell of Rb+, Sr2+, and Y3+, as well as the distinction between the shapes of the 4s-6p 1/2 mirror resonance in the partial 4p 1/2 and 4p 3/2 photoionization cross sections for the Y3+ ion which do not suppress each other in the total photoionization cross section, as is the case for similar resonances in Rb+ and Sr2+. 相似文献
10.
A. M. Tkachuk S. É. Ivanova L. I. Isaenko A. P. Yelisseyev M. -F. Joubert Y. Guyot S. Payne 《Optics and Spectroscopy》2003,95(5):722-740
Optical spectra, intensities of radiative and nonradiative transitions, and luminescence kinetics in erbium-doped potassium-lead double chloride crystals KPb2Cl5:Er3+s(KPC:Er3+) were investigated. The crystals were grown by the Bridgman-Stockbarger method. Their absorption and luminescence spectra were studied experimentally. The crystal-matrix absorption edge was determined at 80 and 300 K. Intensity parameters, radiative transition probabilities, branching ratios, and nonradiative relaxation rates were estimated by the Judd-Ofelt method. The luminescence kinetics from the emitting levels 4 G 11/2, 2 G 9/2, 4 S 3/2, and 4 F 9/2 upon selective excitation was studied. 相似文献
11.
M. L. Savchenko D. A. Kozlov Z. D. Kvon N. N. Mikhailov S. A. Dvoretsky 《JETP Letters》2016,103(5):302-308
The up-conversion luminescence of Er3+ from the 2H11/2, 4S3/2, and 4F9/2 levels in nanocrystals of Y0.95(1?x)Yb0.95xEr0.05PO4 (x = 0, 0.3, 0.5, 0.7, 1) orthophosphates activated with Er3+ ions has been studied under the excitation of Yb3+ ions to the 2F5/2 level by 972-nm cw laser radiation. Broadband radiation in the wavelength range of 370–900 nm has been observed at certain power densities of exciting laser radiation; this broadband radiation is absent in the case of excitation of the powders under study by pulsed laser radiation with a wavelength of 972 nm at a pulse repetition frequency of 10 Hz and a duration of a pulse of 15 ns. Experimental data indicating that this radiation is thermal in nature have been presented. 相似文献
12.
M. V. Stepikhova D. M. Zhigunov V. G. Shengurov V. Yu. Timoshenko L. V. Krasil’nikova V. Yu. Chalkov S. P. Svetlov O. A. Shalygina P. K. Kashkarov Z. F. Krasil’nik 《JETP Letters》2005,81(10):494-497
Population inversion of the energy levels of Er3+ ions in Si/Si1?xGex:Er/Si (x = 0.28) structures has been achieved due to electron excitation transfer from the semiconductor matrix. An analysis of the photoluminescence kinetics at a wavelength of 1.54 μm shows that up to 80% of the Er3+ ions are converted into excited states. This effect, together with the high photoluminescence intensity observed in the structures studied, shows good prospects for obtaining lasers compatible with planar silicon technology. 相似文献
13.
The absorption, luminescence, and excitation spectra of CaF2, SrF2, and BaF2 crystals with EuF3 or YbF3 impurity have been investigated in the range 1–12 eV. In all cases, strong wide absorption bands (denoted as CT1) were observed at energies below the 4f n -4f n ? 15d absorption threshold of impurity ions. Weaker absorption bands (denoted as CT2) with energies 1.5–2 eV lower than those of the CT1 bands have been found in the spectra of CaF2 and SrF2 crystals with EuF3 or YbF3 impurities. The fine structure of the luminescence spectra of CaF2 crystals with EuF3 impurities has been investigated under excitation in the CT bands. Under excitation in the CT1 band, several Eu centers were observed in the following luminescence spectra: C 4v , O h , and R aggregates. Excitation in the CT2 bands revealed luminescence of only C 4v defects. 相似文献
14.
A method of high-resolution time-resolved optical spectroscopy using oscillations of the photon echo intensity in the presence of a perturbation, which splits the optical frequencies of the transitions of two or more ion subgroups, has been proposed and demonstrated. This method has been applied to systems in which the Zee-man effect is manifested. The transition frequencies of ions are switched by a pulsed magnetic field. Oscillations of the photon echo intensity were observed in LiLuF4:Er3+ and LiYF4:Er3+. The first minimum corresponding to the accumulated phase of the electric dipole moment π/2 is reached in the pulsed magnetic field with an amplitude of ~2 G at a duration of 30 ns. The Zeeman splitting in this field is ~10 MHz, which is much less than the laser spectral width (0.15 Å ~ 9 GHz). The g factor of the 4 F 9/2(I) excited state of the Er3+ ion in the LiLuF4 matrix has been determined in zero magnetic field. The comparison with the g-factor value found from the measurement of the absorption spectrum in a magnetic field of 8 kG has been performed. 相似文献
15.
V. E. Kudryashov A. É. Yunovich 《Journal of Experimental and Theoretical Physics》2003,97(5):1015-1019
We present summarized data on the tunneling emission in p-n heterostructures based on GaN and on a series of cubic AIIIBV semiconductors, including GaAs, InP, GaSb, and (Ga, In)Sb. The emission in p-n heterostructures of the InGaN/AlGaN/GaN type in a spectral interval from 1.9 to 2.7 eV predominates at small currents (J<0.2 mA). The position of maximum ?ωmax in the spectrum approximately corresponds to the applied potential difference U:?ωmax=eU. The tunneling emission is related to a high electric field strength in GaN-based heterostructures. The radiative recombination probability is higher in the structures with piezoelectric fields. The observed spectra are compared to the spectra of tunneling emission from light-emitting diodes based on GaAs, InP, and GaSb. The experimental results for various semiconductors emitting in a broad energy range (0.5–2.7 eV) are described by the equation ?ωmax=eU=0.5–2.7 eV. 相似文献
16.
A scheme is proposed for computing the probability of the dipole-forbidden f–f transition at the interaction of the RE3+ impurity ion with the field of an inhomogeneous exciting radiation. It is shown that in the case under consideration, the prohibition on electric dipole transitions can be repealed without involving the Judd–Ofelt theory of induced electric dipole transitions. The quantitative estimation of the absorption cross-section of YAG:Er3+ crystal at the wavelength of 1530 nm (4I15/2 → 4I13/2) was carried out for the simplest model of the inhomogeneous exciting radiation. 相似文献
17.
We demonstrate a stable and efficient passively Q-switched 2.8 μm Er3+-doped ZBLAN fiber laser with a broadband semiconductor saturable absorber mirror. Enabled by the broadband optical modulator, the stable Q-switched fiber laser can deliver a maximum average power over 700 mW with corresponding per-pulse energy of 8.19 μJ and a pulse width of 1.3 μs at a repetition rate of 88.6 kHz under an incident pump power of 3.8 W. In addition, the slope efficiency can reach 22.5%. To the best of our knowledge, this is the highest reported slope efficiency for the passively Q-switched Er3+-doped ZBLAN fiber laser. 相似文献
18.
I. A. Belova F. A. Bol’shchikov Yu. K. Voron’ko A. V. Malov A. V. Popov P. A. Ryabochkina A. A. Sobol’ S. N. Ushakov 《Physics of the Solid State》2008,50(9):1611-1618
This paper reports on the results of the investigation into the intensities of the f-f transitions of Nd3+, Er3+, and Tm3+ ions in calcium niobium gallium garnet (CNGG) crystals. The values of the oscillator strengths and line strengths obtained for hypersensitive transitions and the intensity parameters Ω t of the rare-earth ions in the CNGG crystals are compared with the corresponding quantities for crystals of other garnets and some oxide and fluoride crystals. The assumption is made that an increase in the oscillator strengths and line strengths for the hypersensitive transitions and the intensity parameters Ω2 of the Nd, Er, and Tm ions in the CNGG crystals as compared to those for crystals of other garnets is associated with the specific features revealed in the crystal structure of the calcium niobium gallium garnet, in particular, with the lowering of the symmetry of the positions occupied by rare-earth ions in the crystal structure. 相似文献
19.
The optical transitions 5 D 0, 1 → 7 F J (J = 0, 1, ..., 6) of Eu3+ cubic centers in the CaF2 single crystal are investigated using combined excitation and emission spectroscopy at different time delays after the excitation pulse. The energies of the Stark sublevels of the 7 F J ground states are determined. 相似文献
20.
M. A. Borik T. V. Volkova E. E. Lomonova V. A. Myzina P. A. Ryabochkina N. Yu. Tabachkova A. N. Chabushkin 《Optics and Spectroscopy》2017,122(4):580-587
The structure of the optical centers of Eu3+ ions in tetragonal (ZrO2)1–x–y (Y2O3) x (Eu2O3) y (х = 2.7–3.6; y = 0.1) and cubic (ZrO2)1–x–y (Y2O3) x (Eu2O3) y (х = 8–38; y = 0.1–0.5) crystals of solid solutions on the basis of zirconium dioxide is studied using the methods of optical and Raman-scattering spectroscopy. Characteristic optical centers of Eu3+ ions with different crystalline environments are revealed in the above compounds. 相似文献