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1.
Yu. P. Gnatenko O. A. Shigil’chev E. Rutkovskii G. Contreras-Puente M. Cardenas-Garcia 《Physics of the Solid State》1998,40(4):564-568
Low-temperature photoluminescence, exciton reflection, and multiphonon resonant Raman scattering spectra of Ni-and Co-doped
Zn1−x
MnxTe crystals were investigated. Intense emission occurs in a broad spectral region (1100–17 000 cm−1) in the crystals containing Ni atoms. It is caused by intracenter transitions involving Mn2+ ions and transitions between the conduction band and a level of the doubly charged acceptor. The features of the exciton
photoluminescence and multiphonon resonant Raman scattering involving longitudinal-optical (LO) phonons at various temperatures
are investigated. The insignificant efficiency of the localization of excitons on potential fluctuations in the Zn1−x
MnxTe:Co crystals is established. A temperature-induced increase in the intensity of the 5LO multiphonon resonant Raman scattering
line due to the approach of the conditions for resonance between this line and the ground exciton state is observed in these
crystals.
Fiz. Tverd. Tela (St. Petersburg) 40, 616–621 (April 1998) 相似文献
2.
Conclusions The studies performed here have shown that the superlattice samples studied exhibit photoluminescence spectra which agree
with the Kronig-Penney model, although in calculating the energies of the radiative transitions it is necessary to take into
account the binding energy of the excitons,E
B. Due to the exciton—phonon interaction, the 1HH peak breaks up on the long wavelength side into a Poisson distribution. The
energy of the LO phonon so determined is 34 meV. Bands due toD
0-A
0 andD
0X transitions, caused by remaining low-level impurities in the GaAs crystals are also observed.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 61, Nos. 3–4, pp. 241–245, September–October, 1994. 相似文献
3.
I. V. Kavetskaya N. V. Zamkovets N. N. Sibeldin V. A. Tsvetkov 《Journal of Experimental and Theoretical Physics》1997,84(2):406-416
Luminescence spectra of sufficiently pure n-type indium antimonide crystals (N
D−N
A=(1–22)·1014 cm−3) in a magnetic field of up to 56 kOe, at temperatures of 1.8–2 K, and high optical pumping densities (more than 100 W/cm2) have been studied. More evidence of the existence of electron-hole liquid stabilized by magnetic field has been obtained,
and its basic thermodynamic parameters as functions of magnetic field have been measured. When the magnetic field increases
from 23 to 55.2 kOe, the liquid density increases from 3.2·1015 to 6.7·1015 cm−3, the binding energy per electron-hole pair rises from 3.0 to 5.2 meV, and the binding energy with respect to the ground exciton
level (work function of an exciton in the liquid) rises from 0.43 to 1.2 meV.
Zh. éksp. Teor. Fiz. 111, 737–758 (February 1997) 相似文献
4.
R. T. Kuznetsova T. N. Kopylova K. M. Degtyarenko E. N. Tel'minov V. A. Svetlichnyi G. V. Maier 《Russian Physics Journal》1997,40(4):375-379
We have experimentally investigated the dependence of the luminescence intensity of ethanol solutions of 2-(4-pyridyl)-5-phenyloxazole
on the intensity of the exciting radiation from an XeCl laser (λex = 308 nm, τp = 10 nsec, Eex=1022–1026 photons/cm2·sec). We discuss the measurement technique and possible reasons for the change in radiative properties of the investigated
solutions under the given conditions.
V. D. Kuznetsov Siberian Physicotechnical Institute at Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh
Zavedenii, Fizika, No. 4, pp. 69–74, April, 1997. 相似文献
5.
0 –S1–Sm–Sn multilevel system. An Sm→S1 absorption recovery time of τS1
A=(600±100) fs is determined. The picosecond and femtosecond pulse excitation leads to S0→S1 ground-state absorption bleaching and S1→Sm first excited-state absorption bleaching. The excited-state absorption cross-sections σS1
ex(S1→Sm) and σSm
ex(Sm→Sn) are determined.
Received: 3 June 1996 相似文献
6.
A fluorescence enhancement phenomenon in the europium (Eu)–Ofloxacin (OF)–Sodium Dodecyl Benzene Sulfonate (SDBS) fluorescence
system was observed when Gd3+ was added. The fluorescence intensity of the systems was measured (λ
ex/λ
em = 280/612 nm) at pH 7.8. Under optimum conditions, a linear relationship between the enhanced fluorescence intensity and
the Eu3+ concentration in the range of 5.0 × 10−10 ∼ 2.0 × 10−7 mol·L−1 was observed. The detection limit of Eu3+ was 1.46 × 10−10 mol·L−1 (S/N = 3). This method was used for the determination of trace amounts of europium in synthetic rare earth samples with satisfactory
results. In addition, the interaction mechanism is also studied. 相似文献
7.
We have obtained and analyzed the absorption, fluorescence, and fluorescence excitation spectra of indole vapor, N-acetyl-L-tryptophan
vapor, and 3-indole aldehyde vapor. From analysis of the dependence of the fluorescence spectrum of the free indole molecules
on the wavelength of the exciting radiation λex, it follows that emission of fluorescence occurs when the molecules undergo a transition from the one electronically excited
state 1Lb. The fluorescence spectra of the studied compounds are insignificantly different, suggesting a major role for the indole
chromophore in formation of the compounds. The absorption spectrum of N-acetyl-L-tryptophan, in which the group of atoms is
added to the indole ring through a-C-C bond, is similar to the spectrum of indole, while the spectrum of 3-indole aldehyde
is significantly different from the indole spectrum due to the effect of the C=O group conjugated with the indole ring. The
fluorescence excitation spectra are considerably different from the absorption spectra. This is associated with the strong
dependence of the quantum yield for the free molecules on λex. Qualitatively, they are mirror-symmetric to the fluorescence spectra of the stodied compounds. Analysis of the data obtained
provides a basis for assuming that in the case of free molecules of indole and its derivatives, the 1La absorption in the extreme long-wavelength region of the spectrum does not overlap 1Lb absorption.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 2, pp. 218–222, March–April, 2007. 相似文献
8.
In the paper the dependence of the photorefraction (PhR) in LiNbO3 and LiNbO3−Fe (0.1 wt%, 0.3wt%) crystals on light intensity (within 1016–1023 quanta·cm−2·s−1 at wavelengths 496.5 nm and 600 nm) and temperature (in the region 100–500 K) is studied. For all the crystals the limiting
values of PhR are similar and atT=293 K Δn
sat
lim
≈3·10−3. In LiNbO3 the temperature dependence of PhR in the range 100–500 K requires to take into account at least two trapping centres. 相似文献
9.
A. V. Voitsekhovskii A. G. Korotaev A. P. Kokhanenko D. V. Grigor’ev V. S. Varavin S. A. Dvoretskii Yu. G. Sidorov N. N. Mikhailov N. Kh. Talipov 《Russian Physics Journal》2006,49(9):929-933
The dynamics of accumulation of electrically active radiation defects under ion doping of epitaxial Cd
x
Hg
1−x
Te films is studied for various distributions of film composition in the implantation region. The epitaxial films were irradiated
by boron ions at room temperature in the continuous regime, with the dose ranging within 1011−3·1015 cm−2, energy — 20–150 keV, and ion current density — j = 0.001–0.2 μA·cm−2. It is found that the natural logarithm of the introduction rate of electrically active radiation defects linearly depends
on the epitaxial-film composition in the range of mean projected path of implanted ions. An analysis of the experimental data
shows that the dynamics of accumulation of electrically active radiation defects is determined by the epitaxial-film composition
in the implantation region.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 25–28, September, 2006. 相似文献
10.
The energy level structure of F
3
+
laser color centers in crystals of LiF is discussed. A high-power laser (λ
ex=920 nm) is used to excite luminescence from LiF crystals with F
3
+
centers via two-photon absorption, and the dependence of the polarization and intensity of this luminescence on the polarization
of the laser light is measured and calculated. It is shown that the two-photon transition involves the excitation of a previously
unknown state of the F
3
+
center—a spin singlet whose wave function has 1
A
1 symmetry.
Fiz. Tverd. Tela (St. Petersburg) 39, 1373–1379 (August 1996) 相似文献
11.
M. M. Mikhailov V. V. Neshchimenko Chundong Li Bang-Jiao Ye 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2012,6(1):6-11
The modifying effect of Al2O3, Al2O3 · CeO2, ZrO2, ZrO2 · Y2O3 nanopowders on the photoluminescence spectra of ZnO powder in the 360–660 nm range is investigated. It is found that the
introduction of nanoparticles causes a decrease in the ultraviolet band intensity and an increase in the visual spectral band
intensity. The change in the intensity of elementary components of the visible range band during modification seems to be
explained by the emergence of oxygen and zinc vacancies (V
O+ and V
Zn−) and interstitial oxygen ions (O
i
−). 相似文献
12.
The temperature T
c
of the Kosterlitz-Thouless transition to a superfluid state for a system of magnetoexcitons with spatially separated electrons
e and holes h in coupled quantum wells is obtained as a function of magnetic field H and interlayer separation D. It is found that T
c
decreases as a function of H and D at fixed exciton density n
ex
as a result of an increase in the exciton magnetic mass. The highest Kosterlitz-Thouless transition temperature as a function
of H increases (at small D) on account of an increase in the maximum magnetoexciton density n
ex
versus magnetic field, where n
ex
is determined by a competition between the magnetoexciton energy and the sum of the activation energies of incompressible
Laughlin fluids of electrons and holes.
Pis’ma Zh. éksp. Teor. Fiz. 66, No. 5, 332–337 (10 September 1997)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
13.
Yu. P. Rakovich A. L. Gurskii A. S. Smal’ A. A. Gladyshchuk Kh. Khamadi G. P. Yablonskii M. Khoiken 《Physics of the Solid State》1998,40(5):812-813
The exciton reflectance and photoluminescence spectra of epitaxial ZnSe/GaAs layers with a thickness of 2–4 μm are investigated
in the temperature range 10–120 K. It is shown that one of the causes of the formation of the doublet structure of the A
n=1 photoluminescence band is interference of the exciton radiation at the boundaries of the near-surface dead layer.
Fiz. Tverd. Tela (St. Petersburg) 40, 881–883 (May 1998) 相似文献
14.
Electron paramagnetic resonance studies were conducted on the photoinduced charge transfer and also hyperfine interaction
of U5+ stabilized in photorefractive matrix LiNbO3. This work deals with: (i) first observation of hyperfine structure due to233U (I=5/2) in its pentavalent state at octahedral sites and comparison with other possible site symmetries, (ii) photoinduced charge
transfer as observable by EPR and its relevance to photorefractive behaviour of LiNbO3. The effect of chemical bonding on the hyperfine interaction of 5f
1 configuration was also studied by converting the existing literature data on235U5+ to that of233U5+ by standard methods. This suggests that progressive substitution of oxygen by F−, in the series UO
6
7−
, (UO5F)6− and (UO4F2)5− drastically decreases the hyperfine coupling constantA
∥, along the local distortion axis. This trend is explained as being due to the absence of ligand ion along the distortion
axis at U5+ site in trigonal LiNbO3. The effects of illumination by copper vapor laser (CVL) on the intensity of the U5+ signal was studied in the 10–300K region. The kinetics of decay and restoration of U5+ was also studied between 10–100K range. The decay kinetics was found to obey double exponential. The reduction of concentration
of U5+ with CVL-illumination and its restoration in the absence of light show that pentavalent uranium takes part in the photorefractive
effects in LiNbO3. 相似文献
15.
I. Savatinova I. Savova C.C. Ziling V. Atuchin 《Applied Physics A: Materials Science & Processing》2000,70(5):555-559
Refractive index change and Raman scattering of Z-cut proton-exchanged LiTaO3 optical waveguides with different composition have been studied. Probing of the waveguide depth was carried out by using
micro-Raman spectroscopy in order to distinguish layers with different phase states. Varying the proton-exchange and post-exchange
annealing regimes, two phases –α and β– in addition to the pure LiTaO3, were clearly observed. The behaviour of the A
1 vibrations of the TaO6 groups was found to be very sensitive to the phase changes. Using data from waveguide Raman spectra, normal and oblique E(TO,
LO) phonons were sorted and their properties were followed in the α and β phases. The OH-stretchings are considered to correspond
to dipoles turned out of the oxygen planes.
Received: 9 July 1999 / Accepted: 11 October 1999 / Published online: 24 March 2000 相似文献
16.
Exciton absorption spectra in high-quality β-ZnP2 single crystals have been investigated at T=1.7 K for various directions of the wave vector and various polarization states of the radiation. It has been unambiguously
established that the additional high-energy A series, which in some works has been called a D series and ascribed to ZnP2 crystals, of so-called “rhombic” symmetry,1,8,10,11 is an intrinsic exciton of the β-ZnP2 series. A mixed mode has been detected for the first time, and the energy of the longitudinal exciton has been determined.
The selection rules for the exciton transitions have been analyzed by a group-theoretical approach, and the symmetry of the
nS states of the single exciton has been established on the basis of the experimental data — Γ
2
−
(z).
Fiz. Tverd. Tela (St. Petersburg) 41, 193–202 (February 1999) 相似文献
17.
V. S. Pavlovich 《Journal of Applied Spectroscopy》2007,74(4):501-507
We used known experimental data to analyze the influence of intermolecular interactions on the position of the 0-0-band a1Δg → X3Σ
g
−
phosphorescence of molecular oxygen in solutions. A bathochromic (red) shift caused by dispersion interactions and fluctuations
of the internal electric field (induction effect) is analyzed employing new formulas obtained by us in the framework of the
Onsager model. The contributions from intermolecular repulsion and higher multipole interactions to the shift of the spectrum
are also discussed. It is found that the polarizability in the a1Δg state is higher than in the X3Σ
g
t-
state by 0.19 ± 0.03 Å3. Taking into account the induced nature of O2 phosphorescence in solutions, it is noted that the change of polarizability Δαeg = 0.19 Å3 should differ from the change of Δαeg inherent in free molecular oxygen.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 4, pp. 453–459, July–August, 2007. 相似文献
18.
Y. M. Smirnov 《Journal of Applied Spectroscopy》1998,65(2):161-167
Dissociation-induced excitation of a singly charged cesium ion taking place as a result of collisions of electrons with CsOH
molecules is investigated. Possible reaction channels in the low-energy region are discussed. It is established that sequential
population plays an important role for 6p levels of Cs+.
Moscow Power Engineering Institute, 14, Krasnokazarmennaya St., Moscow, 111250, Russia. Translated from Zhurnal Prikladnoi
Spektroskopii, Vol. 65, No. 2, pp. 159–165, March–April, 1998. 相似文献
19.
We have measured the absorption cross sections of oxygen molecules in oxygen and in an oxygen-argon mixture heated by a shock
wave, in the wavelength range 190–250 nm at temperatures of 1500–7000 K, for thermal equilibrium conditions behind the shock
wave front. Analysis of the absorption cross sections obtained allowed us to select a data set that adequately describes the
absorption characteristics of the electronic transition X3Σ
g
−
→ B3Σ
u
−
for the oxygen molecule.
In order to approximate the temperature dependence of these cross sections at a temperature of 1500–4500 K, we chose the function
σ(λ, T) = σ0(λ)(1 − exp (−θ/T)) exp (− n*θ/T) where θ0 = 1.4·10−17, 1.4·10−17, 1.2·10− 17, and 1.3·10−17 cm2, n* = 3.1, 4.1, 5.6, and 7.47 for wavelengths 190, 210, 230, and 250 nm, respectively; θ = 2240 K is the characteristic temperature
of the O2 molecules. The approximation error was 19–25% and did not exceed the experimental error.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 1, pp. 13–17, January–February, 2006. 相似文献
20.
L. I. Korovin I. G. Lang S. T. Pavlov 《Journal of Experimental and Theoretical Physics》1999,89(4):764-774
Combined polaron states in a rectangular quantum well in a strong magnetic field perpendicular to the well plane are discussed.
These states are due to interaction between two discrete electron levels with different Landau quantum numbers (n and n
1) and different size-quantization quantum numbers (m and m
1) on the one hand and a confined LO phonon on the other under conditions of low temperature when the energy difference between
the electronic levelsis equal or close to the energy of the confined LO phonon. The expression for the resonant magnetic field
H
res at which a combined polaron is formed contains the energy difference between size-quantized levels, so it is a function of
quantum well parameters. The separation ΔE
res between branches in the energy spectrum of a combined polaron and H
res has been calculated as a function of the quantum well width d. The resonant field H
res can be reduced dramatically in comparison with the case m=m
1. The case of size-quantization with n=n
1 has been analyzed. The energy difference ΔE
res is in the range (1–5)· 10−3 eV. The damping of combined polaron states due to the effect of anharmonicity on the LO phonon has been studied. Interband
absorption and features in the reflection spectrum due to interband transitions have been calculated for an arbitrary ratio
between the radiative and “phonon” lifetime of a combined polaron have been investigated.
Zh. éksp. Teor. Fiz. 116, 1419–1439 (October 1999) 相似文献