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1.
It is established that doping of CdS polycrystalline films with alkaline metals (Li, Na, K, Cs) results in an increase of
luminescence intensity by 3–5 times compared with pure films. This increase is accounted for by the placement of alkaline-metal
ions in V
Cd
2−
cation vacancies, which are nonradiative recombination centers in these films. From the dependences of the luminsecence intensity
of the doped films on the synthesis conditions (deposition temperature, concentration of doping impurities, type of doping
metal), the parameters that ensure the maximum luminescence intensity of the films are determined as Tdep ≈ 450°C and CMe = 1·10−5 at %. The luminescence intensity decreases by 1–3% upon exposure of the films to UV light (λmax = 365 nm, I = 1021 quanta·sec·cm−1) for several hours. This is indicative of the stability of these films against UV radiation.
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Translated from Zhurnal Prikladnoi Spektroskopii Vol. 74, No. 3, pp. 362–366, May–June, 2007. 相似文献
2.
It has been found that on exposure of specimens of synthetic opal to UV radiation, luminescence is excited in them (337 nm)
that has spectral maxima at 400 and 500 nm. Its duration at half-height of a pulse is 9 nsec, and there is a weak slow component
with τ ∼ 1 μsec. The spectrum and intensity of the luminescence depend on the duration of irradiation and temperature. The
luminescence bands revealed relate to two individual luminescence centers, namely: the shortwave one, caused by the luminescence
centers formed in the bulk of the opal, and the longwave one, due to those formed on the opal surface.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 5, pp. 622–626, September–October, 2005. 相似文献
3.
Yu. A. Skryshevskii 《Journal of Applied Spectroscopy》2007,74(3):350-356
We have used investigations of low-temperature photoluminescence and thermally stimulated luminescence to study the effect
of acetophenone and pyrene dopants on the photochemical stability of poly(methylphenylsilane) (PMPS) films. We have established
that pure PMPS films and acetophenone-doped PMPS films degrade on exposure to UV radiation due to breaking of Si-Si bonds
followed by formation of crosslinks between the macromolecules. At the same time, pyrene inhibits degradation of PMPS to a
significant extent. This proves that photoinduced breaking of the Si-Si bond can occur upon excitation of the macromolecule
to the first triplet T1(σσ*) state, since acetophenone sensitizes while pyrene quenches the intrinsic phosphorescence of PMPS. So the photochemical
stability of PMPS can be improved by introducing a dopant which quenches triplet excitations of the macromolecule.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 3, pp. 315–320, May–June, 2007. 相似文献
4.
Hrant Yeritsyan Vachagan Harutiunian Volodia Gevorkyan Norair Grigoryan Eleonora Hakhverdyan Sergey Nikoghosyan Aram Sahakyan Rudolf Gevorgyan Hakob Sargisyan Yeghis Keheyan 《Central European Journal of Physics》2005,3(4):623-635
Infrared (IR) absorption and luminescence in chemically and radiation-modified natural Armenian Zeolite (clinoptilolite) samples
have been studied. The luminescence was studied in 390–450 nm and 620–710 nm wavelength bands, and the IR measurements were
carried out in the 400–5400 cm−1 range. It is shown that the luminescence intensity depends on the content of pure clinoptilolite in the samples and, probably
on the distribution of “passive” luminescence centers over Si and Al sites that became “active” under radiation or chemical
treatment. The samples of electron irradiated clinoptilolite have higher luminescence intensity than the chemically and thermally
treated ones. A decrease in the intensity of IR absorption bands at 3550 cm−1 and 3650 cm−1 was found after irradiation. 相似文献
5.
R. N. Nurmukhametov L. V. Volkova V. G. Klimenko S. P. Kabanov R. V. Salov 《Journal of Applied Spectroscopy》2007,74(6):824-830
We have established that exposure of polystyrene-based scintillator samples to UV laser radiation (248 nm) leads to a significant
decrease in the fluorescence intensity. We have carried out a spectral analysis of the luminescent and absorption properties
of the scintillator, which allowed us to determine the major factor in the decrease in luminescence intensity of the samples
exposed to UV radiation. We propose a new hypothesis for the mechanism of the processes leading to the decrease in light output
of the scintillator during operation.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 6, pp. 744–749, November–December, 2007. 相似文献
6.
Yu. V. Zorenko R. M. Turchak T. I. Voznyak A. P. Luchechko 《Journal of Applied Spectroscopy》2006,73(2):211-215
By liquid-phase epitaxy from an aqueous alcoholic solution, we have obtained films of the well-known storage phospor CsBr:Eu,
and we have studied their cathodoluminescence and photoluminescence (PL) spectra compared with the undoped CsBr films. We
have established that the structure of the photoluminescence centers of the CsBr:Eu films when excited by laser radiation
in the absorption band of the Eu2+ ions (λ = 337 nm) includes Eu2+-VCs isolated dipole centers and CsEuBr3 aggregate centers, and also luminescence centers based on inclusions of hydroxyl group OH− with the corresponding emission bands in the 440 nm, 520 nm, and 600 nm regions. We have studied the dependence of the spectra
and the intensity of the photoluminescence for CsBr:Eu films on annealing temperature in air at 423–483 K, compared with analogous
dependences for CsBr:Eu single crystals obtained from the melt. We have shown that annealing the films at T = 423–463 K leads
to rapid formation of CsEuBr3 aggregate luminescence centers, while for T > 473 K thermal degradation of these centers occurs.
We conclude that the observed differences between the photoluminescence spectra of CsBr:Eu films and CsBr:Eu single crystals
may be due to additional doping of the films with OH− ions.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 191–194, March–April, 2006. 相似文献
7.
M. Thambidurai N. Muthukumarasamy N. Murugan Dhayalan Velauthapillai S. Agilan R. Balasundaraprabhu 《Applied Physics A: Materials Science & Processing》2011,104(4):1129-1136
Design of experiment (DOE) based on central composite design (CCD) has been employed for the development of a mathematical
model correlating the important process parameters like thiourea concentration (U), annealing temperature (A), rotational speed (S), and annealing time (T) of the spin coating process for the preparation of CdS thin films. The experiments were conducted as per the design matrix.
Nanocrystalline CdS thin films have been prepared using cadmium nitrate and thiourea as precursors by sol gel spin coating
method using the results of the mathematical model. The prepared CdS films have been characterized and the crystal structure
and grain size of the samples were analyzed using X-ray diffraction technique. The adequacy of the developed models was checked
by analysis of variance (ANOVA) technique. The accuracy of prediction has been carried out by conducting confirmation test.
Using this model, the main effect of process parameters on grain size of CdS films have been studied. These parameters were
optimized to obtain minimum grain size using the Microsoft excel solver. The results have been verified by depositing CdS
films using the optimized conditions. These films have been characterized using X-ray diffraction technique and the grain
size is found to be 8.8 nm. The high resolution transmission electron microscopy (HRTEM) analysis showed the grain size of
the prepared CdS film to be ∼7 nm. UV–vis spectroscopy analysis revealed that CdS films exhibited quantum confinement effect. 相似文献
8.
O. V. Ovchinnikov A. B. Evlev M. A. Efimova V. G. Klyuev A. N. Latyshev A. N. Utekhin A. M. Kholkina 《Journal of Applied Spectroscopy》2005,72(6):809-813
An anti-Stokes luminescence band with λmax = 515 nm of microcrystals of solid AgCl0.95I0.05 solutions excited by a radiation flux of density 1013–1015 quanta/cm2·sec in the range 600–800 nm at 77 K was detected. It is shown that the intensity of this luminescence and the frequency of
its excitation depend on the prior UV-irradiation of samples. Analysis of the stimulated-photoluminescence spectra and the
anti-Stokes luminescence excitation spectra of the indicated microcrystals has shown that to the centers of anti-Stokes luminescence
excitation correspond local levels in the forbidden band of the crystals. These states are apparently due to the atomic and
molecular disperse silver particles that can be inherent in character or formed as a result of a low-temperature photochemical
process.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 6, pp. 738–742, November–December, 2005. 相似文献
9.
We have studied the photoluminescence of calcite crystals. In the blue region of the photoluminescence spectrum of calcite
crystals obtained from Siberia (Russia) and from Saaremaa Island (Estonia), three strongly overlapping luminescence bands
due to intrinsic defects are observed. Luminescence due to impurities in the crystals are hardly detectable. The experimentally
measured time dependence of the luminescence intensity for the indicated luminescence bands is compared with the dependences
obtained as a result of a calculation based on a proposed model for the luminescence center. Better agreement between experiment
and calculation is achieved if the model of the luminescence center includes a metastable level with electron ejection energy
of 4 meV; the characteristic time for the radiative transition is 1.3 nsec. Studying the time dependence of the luminescence
at different wavelengths within the indicated bands allows us to conclude that the photoluminescence (three bands) is due
to one type of luminescence center.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 4, pp. 498–501, July–August, 2006. 相似文献
10.
The luminescence and luminescence excitation spectra of thin films of Bi4Ge3O12 and Bi2Ge3O9 were investigated. The spectra were decomposed into elementary components by the Alentsev-Fok method. It has been established
that the luminescence spectra of thin Bi4Ge3O12 and Bi2Ge3O9 films have a similar structure and that each contains three luminescence bands with maxima at 2.70, 2.40, and 2.05 eV and
at 2.73, 2.40, and 1.95 eV, respectively. Comparison of the results obtained with the well-known results of investigation
of the luminescence of Bi12GeO20 and Bi2O3 suggests that the luminescence in the compounds considered is caused by the radiation processes that proceed in structural
complexes of similar configuration that contain the bismuth ion in the nearest oxygen environment.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 3, pp. 377–380, May–June, 2005. 相似文献
11.
S. B. Meshkova Z. M. Topilova M. O. Lozinskii D. V. Bol'shoi 《Journal of Applied Spectroscopy》1997,64(2):229-233
It is shown that luminescence quenching of lanthanide (Ln) ions by water molecules (OH-oscillators) entering the first coordination
sphere of a complex decreases as the chain of the fluorinated radical lengthens from CF3 to C6F13. The amounts of water molecules in binary and different-ligand Eu complexes with some fluoro derivatives of acetyl acetone
are determined. It is established that, unlike OH-oscillators, the elimination of hydrogen oscillations at the central carbon
atom by β-diketone deuteration provides the same increase (1.1–1.2 fold) in luminescence intensity in all the investigated
Eu complex compounds.
A. V. Bogatskii Physicotechnical Institute, National Academy of Sciences of Ukraine, 86, Lyustdorfskaya Read, Odessa, 270080,
Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 2, pp. 217–220, March–April, 1997. 相似文献
12.
V. A. Sokol M. M. Pinaeva E. A. Gurskaya A. A. Stekol’nikov 《Journal of Applied Spectroscopy》2000,67(2):376-379
The luminescence of europium in anode oxide films (AOF) on titanium-aluminum film composites is investigated. It is shown
that the intensity distribution in the continuous and line luminescence spectra of europium introduced into the AOF directly
in the process of anodic oxidation essentially depends on the sequence of arrangement of the layers of metal films and on
the temperature of their heat treatment preceding the process of anodic oxidation. It is established that the nature of the
luminescence spectrum of the AOF correlates with the chronovoltammetry diagrams of anodic oxidation. Composites with a high
degree of europium doping are found and methods of searching for composites for creating new materials of electronic technology
are outlined.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 2, pp. 270–272, March–April, 2000. 相似文献
13.
A. V. Kukhto É. É. Kolesnik A. L. Gurskii E. V. Lutsenko K. A. Osipov V. N. Pavlosvskii Yu. V. Grazulyavichyus A. Nedelcheva I. K. Grabchev 《Journal of Applied Spectroscopy》2007,74(6):915-920
We have studied the effect of the intensity of the exciting radiation and the temperature on the emission properties of two
kinds of thin-film samples based on blends of two types of organic electroactive materials: polyfluorene + iridium triphenylpyridinate
and polyepoxypropylcarbazole + zero-th order PAMAM dendrimer with eosin. We have shown that an increase in the excitation
intensity leads to an increase in the intensity of the luminescence of the polymer matrices and the iridium complex up to
a power density of 300 kW/cm2, and the emission of the dendrimer is rapidly saturated and does not return to the initial value when the excitation level
decreases. Heating up to 170°C followed by cooling causes an increase in the intensity for all the components except the dendrimer.
The data obtained show that annealing is an important method for improving the emission efficiency of the proposed thin-film
structures, due to a change in the packing of the activator molecules in the polymer matrix leading to more efficient transfer
of the excitation energy. Molecules of the studied dendrimer are not stable when exposed to optical radiation and temperature.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 6, pp. 820–825, November–December, 2007. 相似文献
14.
The intensity of the luminescence generally increases with radiation dose and measurement of these phenomena can be used to characterise the degree of dependence on beta doses. In this study, in order to test whether this is a significant problem on the optically stimulated luminescence (OSL) studies, the radiation dose response of the OSL signal from samples of chlorides contained in feldspars have been investigated by irradiating the samples with beta doses. The infrared-emitting diodes were used with a wavelength of (880±80) nm, and an IRSL (infrared stimulated luminescence) intensity parametres, m, was described and found m = 1±0.03. 相似文献
15.
Different electroluminescence spectrums of the blueλ
max
=420 nm wide-banded low-temperature low-voltage radiation of CdF2-RE films at different levels of excitation in the region of temperatures of 77–300K are investigated. The kinetic characteristics
and temperature dependence of this radiation are explored. An effect of the resonance interaction of the centers of luminescence
of the wide-band and line radiation of the RE-centers is found. A model of the center of the wide-band radiation is suggested.
It is shown that the “blue” radiation is caused by recombination of the carriers.
Institute of Physics of Semiconductors of the National Academy of Sciences of Ukraine, Nauka Ave., 45, 252028, Kiev. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 1, pp. 127–132, January–February, 1999. 相似文献
16.
Cadmium sulfide (CdS) with different morphologies was successfully prepared by solvothermal process by controlling the processing
parameters, including nature of precursor and solvent, reaction temperature and process time. X-ray diffraction patterns revealed
that, in all cases highly pure and crystallized CdS with hexagonal structure were obtained. In addition, it was found that
the processing parameters influence on preferable growth direction of CdS nanostructures. Field emission scanning electron
microscope analysis showed that CdS nanowires with different aspect ratios were obtained (depending upon the reaction temperature
and process time) in presence of sulfur powder and ethylenediamine, whereas CdS nanoparticles were produced by sulfur powder
and ethanolamine. Moreover, CdS nanorods were prepared using thiourea and ethylenediamine. Transmission electron microscope
image confirmed that CdS nanowire with one of the highest aspect ratio reported in the literature (i.e., 255) was achieved
using sulfur powder and ethylenediamine at 200 °C reaction temperature for 72 h process time. UV–Vis absorption spectra of
CdS nanostructures prepared under different conditions displayed a blue shift relative to that of bulk CdS due to the quantum
size effect. 相似文献
17.
The kinetics of fluorescence polarization in intense pulse excitation of solid disordered solutions of bichromophores that
consist of complex molecules of two types between which there can be inductiveresonance transfer of electron-excitation energy
is theoretically investigated. Variants of fluorescence excitation by single pulses and pulse trains are considered. The lifetime
of the fluorescence of a given solution increases with the intensity of the exciting pulses. The possibility of controlling
the duration of fluorescence attenuation for donor molecules incorporated into the bichromophores by the action of luminescence
radiation at the frequency of acceptor-molecule absorption on the solution is demonstrated.
Belarusian State University, 4, F. Skorina Ave., Minsk, 220050, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii
Vol. 65, No. 4, pp. 546–550, July–August, 1998. 相似文献
18.
For an ensemble of different types of luminescence centers with overlapping absorption bands, with no restrictions on the
optical densities, we have obtained relations describing the luminescence excitation spectra for each type of center. We consider
transformations of the relations in some limiting cases. We suggest a procedure for using the equations obtained to determine
the characteristics of the luminescence centers. Some of these procedures have been experimentally implemented in study of
intrinsic radiation color centers in lithium fluoride crystals. We have determined the ratios of the luminescence quantum
yields for F2 and F3+ color centers, and we have observed that a major role is played by nonradiative transitions in deactivation of the first
excited singlet state of F3+ centers.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 3, pp. 365–371, May–June, 2008. 相似文献
19.
N. V. Gaponenko G. K. Malyarevich A. V. Mudryi O. B. Gusev M. V. Stepikhova M. Yu. Tsvetkov S. M. Kleshcheva M. I. Samoilovich A. P. Stupak 《Journal of Applied Spectroscopy》2007,74(5):687-691
We have studied the luminescence and luminescence excitation spectra of erbium in the 1.54 μm region in titanium oxide and
silicon oxide xerogels, formed in the mesoscopic pores of three-dimensional synthetic opals and two-dimensional porous aluminum
oxide structures. For erbium-doped titanium oxide films formed in opal, in contrast to analogous films on porous aluminum
oxide, in the luminescence excitation spectra we observe an intense broad band with a maximum in the ∼360 nm region. We discuss
the possible nature of this band.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 622–626, September–October, 2007. 相似文献
20.
In a suitable pH buffer solutions, sodium diethyldithiocarbamate (DDTC) reacts with some divalence metal ions M(II) to form
(M–DDTC)
n
chelate complex nanoparticles, which exhibit different luminescence properties. There is a strongest luminescence peak at
470 nm for the Co(II)–DDTC system, three peaks at 330, 470, and 630 nm for the Cu(II)–DDTC system, three peaks at 420, 470,
and 630 nm for the Cd(II)–DDTC system, four peaks at 350, 400, 435, and 470 nm for the Ni(II)–DDTC system, two peaks at 408
and 470 nm for the Pb(II)–DDTC system, two peaks at 415 and 470 nm for the Fe(II)–DDTC system. The different luminescence
properties of (M–DDTC)
n
chelate complex nanoparticles was explained. Under the optimal conditions, the luminescence intensity of (Co–DDTC)
n
chelate complex nanoparticles at 470 nm (F
470 nm) is linear to Co(II) concentration in the range of 0.012–1.44 μg/mL. The detection limit is 0.0023 μg/mL. A novel luminescence method has been proposed for the determination of cobalt in Vitamin B12 samples, with satisfactory results. 相似文献