The paper studied the luminescent properties of lead fluoride silicate nanostructured glassceramics doped with ytterbium and erbium ions. We have measured luminescence spectra of glassceramics in the visible and near-IR ranges at temperatures of 300 and 77 K and under their pumping at a wavelength of 975 nm. We have examined changes in the luminescence spectra of glassceramics depending on the time of their secondary thermal treatment, concentration of dopant ions, specimen temperature, and power of exci-tation radiation.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3551

Aseev, V.A.

Kolobkova, E.V.

Nekrasova, Ya.A.

Nikonorov, N.V.

Nuryev, R.K.

Rokhmin, A.S.

Electronic Sumy State University Institutional Repository

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE  NANOMATERIALS: APPLICATIONS AND PROPERTIES Vol. 2 No 4, 04NEA14(3pp) (2013)   2304-1862/2013/2(4)04NEA14(3) 04NEA14-1  2013 Sumy State University Up-conversion and IR Luminescence of Ytterbium–Erbium  Oxyfluoride Silicate Glassceramics   V.A. Aseev*, E.V. Kolobkova†, Ya.A. Nekrasova‡,N.V. Nikonorov§, R.K. Nuryev** and A.S. Rokhmin††   St. Petersburg National Research University of Information Technologies, Mechanics and Optics, 49, Kronverkskiy pr., 197101 Saint-Petersburg, Russia  (Received 18 June 2013; published online 03 September 2013)  The paper studied the luminescent properties of lead fluoride silicate nanostructured glassceramics doped with ytterbium and erbium ions. We have measured luminescence spectra of glassceramics in the visible and near-IR ranges at temperatures of 300 and 77 K and under their pumping at a wavelength of 975 nm. We have examined changes in the luminescence spectra of glassceramics depending on the time of their secondary thermal treatment, concentration of dopant ions, specimen temperature, and power of exci-tation radiation.  Keywords: Up-conversion Luminescence, Ytterbium–Erbium Glassceramic, IR Luminescence, Low Tem-perature Luminescence, Solar Cell.   PACS numbers: 71.55.Jv, 78.55.Qr                                                    * Aseev @oi.ifmo.ru † Kolobok106@rambler.ru ‡ Nekrasova@oi.ifmo.ru § Nikonorov@oi.ifmo.ru ** Nuryev@oi.ifmo.ru †† Rokhmin@oi.ifmo.ru 1. INTRODUCTION  In recent years, optical materials doped with rare-earth ions have been of increased interest for investiga-tions, since they are becoming more and more widely used in various fields of science and technology, for example, as phosphors for solar cells, white light-emitting diodes and sensors, active media for fiber la-sers and optical amplifiers, and mini- and micro-chips lasers. Of trivalent rare-earth ions, erbium attracts the greatest attention because of its upconversion  charac-teristics. However, the low absorption cross section of erbium at a wavelength of 980 nm restricts its com-mercial applicability. Ytterbium ions have strong and broad absorption bands, which coincide with the radia-tion range of InGaAs-based laser diodes; also, they are efficient sensitizers for erbium. It is well known that oxygen-free glass matrices, e.g., the fluoride matrix, are more favorable than are oxygen-containing matrices. This is related to a decrease in the probability of non-radiative energy transfer from the rare-earth ion to surrounding matrix ions. However, synthesis of fluo-ride materials is complicated and laborious. Special precautions are required to prevent contact of the ma-terial to be synthesized with the atmosphere. In addi-tion, the chemical and thermal stability of these mate-rials and their mechanical strength are low compared to oxide glasses. It should also be noted that optical fiber drawing based on oxygen-free fluoride glasses presents a significant problem. At present, a simpler and less expensive way for obtaining materials with a low-phonon spectrum is synthesis of oxide–fluoride glassceramics doped with rare-earth ions (such as, e.g., erbium, ytterbium, etc.) that are incorporated in nano-crystalline phase. Glassceramics combines the best properties of glasses and crystals and has wide range of advantages. If rare-earth ions enter into the crystal phase, the spectral–luminescent properties of such glassceramics are close to the properties of correspond-ing single-crystal analogs. As drawbacks of these mate-rials, one can note the complexity of the technology of their production, as well as light scattering at bounda-ries between glassy and crystalline phases. In order to reduce the light-scattering effect and obtain required properties of glassceramics, it is necessary to optimize the main parameters of the crystalline phase, such as the size and volume fraction. In turn, these parameters depend on the temperature and duration of the second-ary thermal treatment (i.e., thermal treatment under which a spontaneous growth of the crystalline phase in the glass matrix is observed). Decreasing the size of the crystalline phase to 10–50 nm makes it possible to con-siderably reduce the light scattering in glassceramics and classify the heterophase structure as an optical material or, if this medium is doped with rare-earth ions, as a laser material. In [1], the possibility of creation of a new laser ma-terial – nanostructured lead fluoride silicate glass-ceramics doped with rare-earth ions and that contains nanocrystals of lead lanthanide oxyfluorides with a size of 10–40 nm has been shown. In [2, 3], the spectral–luminescent properties of new lead fluoride silicate nano-glassceramics have been investigated. Based on X-ray diffractometry and optical spectroscopy, the au-thors of [1–3] experimentally showed that rare-earth ions enter into the nanosized crystalline phase. The objective of this work was to study effects of thermal treatment time, the power of excitation radiation, and the concentration of erbium ions on the luminescence spectra of nanostructured lead fluoride glassceramics at temperatures of 300 and 77 K.  V.A. ASEEV, E.V. KOLOBKOVA, YA.A. NEKRASOVA ET AL. PROC. NAP 2, 04NEA14 (2013)   04NEA14-2 2. TECHNOLOGY AND EXPERIMENTS  In the work, we investigated samples of the follow-ing composition: 30SiO2–18PbF2–15AlO3/2–5ZnF2– 29CdF2–3YbF3–хErF3 (х  0.05–0.5). The concentration of ytterbium fluoride was constant, being 3 mol , the concentration of ErF3 was varied from 0.05 to 0.5 mol .  Based on the obtained DSC data, the thermal treatment was performed at a temperature of 515°C, i.e., at the beginning of the peak of the volume crystal-lization. The time of secondary thermal treatment was varied between 30 and 600 min. The choice of thermal-treatment temperature is determined by the possibility of controlling the rate growth of nanocrystals and their size (not greater than 60 nm in diameter) in order to reduce losses for scattering.  The luminescence spectra were measured in the wavelength ranges 350–700 nm and 1400–1650 nm with a step of 0.1 nm at temperatures of 300 and 77 K. Luminescence was excited with diode laser (975 nm). The luminescence spectra in the visible range were normalized to unity based on the peak in the red spec-tral range (~650–670 nm).  3. RESULT AND DISCUSSION   In work [1], X-ray analysis showed that a new com-pound of lead lanthanide oxyfluorides (PbLnF3) was precipitated in glass host as a nanosized crystal compo-sition PbYb(1 – x)ErxОF3. The size of crystals was about 30–40 nm. With increasing concentration of Er3+ ions in ytterbium-erbium nanoglassceramics, the vol-ume of the crystalline phase increases. Comparison the luminescence spectra of the glass and glassceramics at room temperature showed that six peaks are observed in the luminescence spectrum of the nanoglassceram-ics. However, in the spectrum of the glass, only five peaks in the visible range are observed and there is no band in the UV range. That is, after the thermal treatment, the probabilities of radiative transitions change. The intensity of the luminescence peak at 415 nm increases (the radiative probability increases), whereas the luminescence in the entire remaining spectral range 450–575 nm decreases with respect to the normalization peak (the radiative probability de-creases). Let us compare the luminescence spectra ob-tained at different measurement temperatures (Fig. 1).     Fig. 1 – The effect of the temperature of the specimen on the luminescence spectra of nano_glass_ceramics: (1) 300 and (2) 77 K (the concentration of ErF3 is 0.5 mol %). The inset shows the luminescence band 530–590 nm.  At room temperature, in the visible spectral range, one observes luminescence bands with maxima at 520 and 550 nm, which correspond to the transitions 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2, respectively (Fig. 1a); however, at 77 K, the peak with the maximum at 520 nm is not observed. This is related to the fact that the mechanism by which the level 2H11/2 is populated oc-curs because of the excitation transfer from the lower-lying energy level 4S3/2 at the expense of the thermal energy. At 77 K, the thermal energy (kT) is too low for the transition between the levels 2H11/2 and 4S3/2 to oc-cur; i.e., temperature redistribution does not occur. The lowering of the temperature leads to a narrowing of the luminescence spectra in the IR range from 68 to 23 nm (Fig. 1b). Comparison of the shapes of the luminescence spectra for the initial glass and glassceramics shows that the spectrum of the glassceramics is more clearly structured and a greater number of Stark sublevels are observed. This proves that erbium ions enter the crys-talline phase upon thermal treatment. Also, as the time of the thermal treatment increases, it is observed that the relative intensity of the luminescence bands 375–575 nm increases; i.e., the probabilities of radiative transitions from different levels depend on the crystal size. The luminescence intensity is significantly affect-ed by a change in the concentration of dopant ions in the composition of the specimen. Upon an increase in the concentration of erbium, the luminescence relative intensity decreases in the entire investigated spectral range, namely, of the bands at 415, 475, and 550 nm. Also in order to gain a deeper insight into mechanisms of upconversion luminescence, we measured the de-pendence of luminescence intensity on pumping power. With an increase in the excitation power, the lumines-cence intensity in the blue range increases with respect to the intensity of the red band of the spectrum, while the intensity in the green range decreases.  4. CONCLUSIONS  In this work, we have examined the luminescent properties of nanostructured glassceramics doped with  UP-CONVERSION AND IR LUMINESCENCE… PROC. NAP 2, 04NEA14 (2013)   04NEA14-3 ytterbium and erbium ions at room temperature (300 K) and temperature of liquid nitrogen (77 K).  Upon an increase in the time of the secondary thermal treatment, the ratio of peak intensities with respect to the normalization peak changes; namely, there is an increase in the intensity of peaks in the range of 415 and 520–550 nm. Also, we have observed intense upconversion luminescence in the blue (415 nm), green (475, 520, and 550 nm), and red (~ 670 nm) spectral ranges.  Obtained ytterbium-erbium nano-glassceramics can be used as material for solar cell.  AKNOWLEDGEMENTS  This work was supported by the federal targeted program “Scientific and Pedagogical Personnel of Inno-vative Russia (2009–2013)” (agreement no. 14.B37.21.0169 of the Ministry of Education and Sci-ence of the Russian Federation)   REFERENCES  1. V.A. Aseev, V.V. Golubkov, E.V. Kolobkova, N.V. Nikonorov, Fiz. Khim. Stekla 38 (2), 238 (2012). 2. V.A. Aseev, V.V. Golubkov, A.V. Klement’eva, E.V. Kolobkova, N.V. Nikonorov, Opt. Spektrosk. 106 (5), 770 (2009). 3. V.A. Aseev, Yu.A. Varaksa, A.V. Klement’eva, E.V. Kolobkova, N.V. Nikonorov, G.V. Sinitsyn, M.A. Khodasevich, Opt. Spek-trosk. 108 (5), 763 (2010).  

Up-conversion and IR Luminescence of Ytterbium–Erbium Oxyfluoride Silicate Glassceramics

SocioEconomic Challenges Journal (Sumy State University)

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE  
NANOMATERIALS: APPLICATIONS AND PROPERTIES 
Vol. 2 No 4, 04NEA14(3pp) (2013) 
 
 
2304-1862/2013/2(4)04NEA14(3) 04NEA14-1  2013 Sumy State University 
Up-conversion and IR Luminescence of Ytterbium–Erbium  
Oxyfluoride Silicate Glassceramics  
 
V.A. Aseev*, E.V. Kolobkova†, Ya.A. Nekrasova‡,N.V. Nikonorov§, R.K. Nuryev** and A.S. Rokhmin††  
 
St. Petersburg National Research University of Information Technologies, Mechanics and Optics, 49, Kronverkskiy 
pr., 197101 Saint-Petersburg, Russia 
 
(Received 18 June 2013; published online 03 September 2013) 
 
The paper studied the luminescent properties of lead fluoride silicate nanostructured glassceramics 
doped with ytterbium and erbium ions. We have measured luminescence spectra of glassceramics in the 
visible and near-IR ranges at temperatures of 300 and 77 K and under their pumping at a wavelength of 
975 nm. We have examined changes in the luminescence spectra of glassceramics depending on the time of 
their secondary thermal treatment, concentration of dopant ions, specimen temperature, and power of exci-
tation radiation. 
 
Keywords: Up-conversion Luminescence, Ytterbium–Erbium Glassceramic, IR Luminescence, Low Tem-
perature Luminescence, Solar Cell. 
 
 PACS numbers: 71.55.Jv, 78.55.Qr 
 
 
                                                 
* Aseev @oi.ifmo.ru 
† Kolobok106@rambler.ru 
‡ Nekrasova@oi.ifmo.ru 
§ Nikonorov@oi.ifmo.ru 
** Nuryev@oi.ifmo.ru 
†† Rokhmin@oi.ifmo.ru 
1. INTRODUCTION 
 
In recent years, optical materials doped with rare-
earth ions have been of increased interest for investiga-
tions, since they are becoming more and more widely 
used in various fields of science and technology, for 
example, as phosphors for solar cells, white light-
emitting diodes and sensors, active media for fiber la-
sers and optical amplifiers, and mini- and micro-chips 
lasers. Of trivalent rare-earth ions, erbium attracts the 
greatest attention because of its upconversion  charac-
teristics. However, the low absorption cross section of 
erbium at a wavelength of 980 nm restricts its com-
mercial applicability. Ytterbium ions have strong and 
broad absorption bands, which coincide with the radia-
tion range of InGaAs-based laser diodes; also, they are 
efficient sensitizers for erbium. It is well known that 
oxygen-free glass matrices, e.g., the fluoride matrix, are 
more favorable than are oxygen-containing matrices. 
This is related to a decrease in the probability of non-
radiative energy transfer from the rare-earth ion to 
surrounding matrix ions. However, synthesis of fluo-
ride materials is complicated and laborious. Special 
precautions are required to prevent contact of the ma-
terial to be synthesized with the atmosphere. In addi-
tion, the chemical and thermal stability of these mate-
rials and their mechanical strength are low compared 
to oxide glasses. It should also be noted that optical 
fiber drawing based on oxygen-free fluoride glasses 
presents a significant problem. At present, a simpler 
and less expensive way for obtaining materials with a 
low-phonon spectrum is synthesis of oxide–fluoride 
glassceramics doped with rare-earth ions (such as, e.g., 
erbium, ytterbium, etc.) that are incorporated in nano-
crystalline phase. Glassceramics combines the best 
properties of glasses and crystals and has wide range of 
advantages. If rare-earth ions enter into the crystal 
phase, the spectral–luminescent properties of such 
glassceramics are close to the properties of correspond-
ing single-crystal analogs. As drawbacks of these mate-
rials, one can note the complexity of the technology of 
their production, as well as light scattering at bounda-
ries between glassy and crystalline phases. In order to 
reduce the light-scattering effect and obtain required 
properties of glassceramics, it is necessary to optimize 
the main parameters of the crystalline phase, such as 
the size and volume fraction. In turn, these parameters 
depend on the temperature and duration of the second-
ary thermal treatment (i.e., thermal treatment under 
which a spontaneous growth of the crystalline phase in 
the glass matrix is observed). Decreasing the size of the 
crystalline phase to 10–50 nm makes it possible to con-
siderably reduce the light scattering in glassceramics 
and classify the heterophase structure as an optical 
material or, if this medium is doped with rare-earth 
ions, as a laser material. 
In [1], the possibility of creation of a new laser ma-
terial – nanostructured lead fluoride silicate glass-
ceramics doped with rare-earth ions and that contains 
nanocrystals of lead lanthanide oxyfluorides with a size 
of 10–40 nm has been shown. In [2, 3], the spectral–
luminescent properties of new lead fluoride silicate 
nano-glassceramics have been investigated. Based on 
X-ray diffractometry and optical spectroscopy, the au-
thors of [1–3] experimentally showed that rare-earth 
ions enter into the nanosized crystalline phase. The 
objective of this work was to study effects of thermal 
treatment time, the power of excitation radiation, and 
the concentration of erbium ions on the luminescence 
spectra of nanostructured lead fluoride glassceramics 
at temperatures of 300 and 77 K. 
 V.A. ASEEV, E.V. KOLOBKOVA, YA.A. NEKRASOVA ET AL. PROC. NAP 2, 04NEA14 (2013) 
 
 
04NEA14-2 
2. TECHNOLOGY AND EXPERIMENTS 
 
In the work, we investigated samples of the follow-
ing composition: 30SiO2–18PbF2–15AlO3/2–5ZnF2– 
29CdF2–3YbF3–хErF3 (х  0.05–0.5). The concentration 
of ytterbium fluoride was constant, being 3 mol , the 
concentration of ErF3 was varied from 0.05 to 
0.5 mol .  
Based on the obtained DSC data, the thermal 
treatment was performed at a temperature of 515°C, 
i.e., at the beginning of the peak of the volume crystal-
lization. The time of secondary thermal treatment was 
varied between 30 and 600 min. The choice of thermal-
treatment temperature is determined by the possibility 
of controlling the rate growth of nanocrystals and their 
size (not greater than 60 nm in diameter) in order to 
reduce losses for scattering.  
The luminescence spectra were measured in the 
wavelength ranges 350–700 nm and 1400–1650 nm 
with a step of 0.1 nm at temperatures of 300 and 77 K. 
Luminescence was excited with diode laser (975 nm). 
The luminescence spectra in the visible range were 
normalized to unity based on the peak in the red spec-
tral range (~650–670 nm). 
 
3. RESULT AND DISCUSSION  
 
In work [1], X-ray analysis showed that a new com-
pound of lead lanthanide oxyfluorides (PbLnF3) was 
precipitated in glass host as a nanosized crystal compo-
sition PbYb(1 – x)ErxОF3. The size of crystals was 
about 30–40 nm. With increasing concentration of Er3+ 
ions in ytterbium-erbium nanoglassceramics, the vol-
ume of the crystalline phase increases. Comparison the 
luminescence spectra of the glass and glassceramics at 
room temperature showed that six peaks are observed 
in the luminescence spectrum of the nanoglassceram-
ics. However, in the spectrum of the glass, only five 
peaks in the visible range are observed and there is no 
band in the UV range. That is, after the thermal 
treatment, the probabilities of radiative transitions 
change. The intensity of the luminescence peak at 415 
nm increases (the radiative probability increases), 
whereas the luminescence in the entire remaining 
spectral range 450–575 nm decreases with respect to 
the normalization peak (the radiative probability de-
creases). Let us compare the luminescence spectra ob-
tained at different measurement temperatures (Fig. 1). 
 
  
 
Fig. 1 – The effect of the temperature of the specimen on the luminescence spectra of nano_glass_ceramics: (1) 300 and (2) 77 K 
(the concentration of ErF3 is 0.5 mol %). The inset shows the luminescence band 530–590 nm. 
 
At room temperature, in the visible spectral range, 
one observes luminescence bands with maxima at 520 
and 550 nm, which correspond to the transitions 
2H11/2 → 4I15/2 and 4S3/2 → 4I15/2, respectively (Fig. 1a); 
however, at 77 K, the peak with the maximum at 520 
nm is not observed. This is related to the fact that the 
mechanism by which the level 2H11/2 is populated oc-
curs because of the excitation transfer from the lower-
lying energy level 4S3/2 at the expense of the thermal 
energy. At 77 K, the thermal energy (kT) is too low for 
the transition between the levels 2H11/2 and 4S3/2 to oc-
cur; i.e., temperature redistribution does not occur. The 
lowering of the temperature leads to a narrowing of the 
luminescence spectra in the IR range from 68 to 23 nm 
(Fig. 1b). Comparison of the shapes of the luminescence 
spectra for the initial glass and glassceramics shows 
that the spectrum of the glassceramics is more clearly 
structured and a greater number of Stark sublevels are 
observed. This proves that erbium ions enter the crys-
talline phase upon thermal treatment. Also, as the time 
of the thermal treatment increases, it is observed that 
the relative intensity of the luminescence bands 375–
575 nm increases; i.e., the probabilities of radiative 
transitions from different levels depend on the crystal 
size. The luminescence intensity is significantly affect-
ed by a change in the concentration of dopant ions in 
the composition of the specimen. Upon an increase in 
the concentration of erbium, the luminescence relative 
intensity decreases in the entire investigated spectral 
range, namely, of the bands at 415, 475, and 550 nm. 
Also in order to gain a deeper insight into mechanisms 
of upconversion luminescence, we measured the de-
pendence of luminescence intensity on pumping power. 
With an increase in the excitation power, the lumines-
cence intensity in the blue range increases with respect 
to the intensity of the red band of the spectrum, while 
the intensity in the green range decreases. 
 
4. CONCLUSIONS 
 
In this work, we have examined the luminescent 
properties of nanostructured glassceramics doped with 
 UP-CONVERSION AND IR LUMINESCENCE… PROC. NAP 2, 04NEA14 (2013) 
 
 
04NEA14-3 
ytterbium and erbium ions at room temperature 
(300 K) and temperature of liquid nitrogen (77 K).  
Upon an increase in the time of the secondary 
thermal treatment, the ratio of peak intensities with 
respect to the normalization peak changes; namely, 
there is an increase in the intensity of peaks in the 
range of 415 and 520–550 nm. Also, we have observed 
intense upconversion luminescence in the blue 
(415 nm), green (475, 520, and 550 nm), and red 
(~ 670 nm) spectral ranges.  
Obtained ytterbium-erbium nano-glassceramics can 
be used as material for solar cell. 
 
AKNOWLEDGEMENTS 
 
This work was supported by the federal targeted 
program “Scientific and Pedagogical Personnel of Inno-
vative Russia (2009–2013)” (agreement no. 
14.B37.21.0169 of the Ministry of Education and Sci-
ence of the Russian Federation) 
 
 
REFERENCES 
 
1. V.A. Aseev, V.V. Golubkov, E.V. Kolobkova, N.V. Nikonorov, 
Fiz. Khim. Stekla 38 (2), 238 (2012). 
2. V.A. Aseev, V.V. Golubkov, A.V. Klement’eva, E.V. Kolobkova, 
N.V. Nikonorov, Opt. Spektrosk. 106 (5), 770 (2009). 
3. V.A. Aseev, Yu.A. Varaksa, A.V. Klement’eva, E.V. Kolobkova, 
N.V. Nikonorov, G.V. Sinitsyn, M.A. Khodasevich, Opt. Spek-
trosk. 108 (5), 763 (2010). 
 


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Up-conversion and IR Luminescence of Ytterbium–Erbium Oxyfluoride Silicate Glassceramics

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