The aim of our work was synthesis of transparent silicious media high-doped with Yb–Er, Yb–Ho and Yb–Eu and determination of the media structure and spectral-luminescent properties in the anti-Stokes region at excitation through the Yb3+ ions

Khodasevich, I.A.

Kouhar, V.V.

Malashkevich, G.E.

Pestryakov, E.V.

English

SocioEconomic Challenges Journal (Sumy State University)

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE  
NANOMATERIALS: APPLICATIONS AND PROPERTIES 
Vol. 3 No 2, 02NAESF10(2pp) (2014) 
 
 
2304-1862/2014/3(2)02NAESF10(2) 02NAESF10-1  2014 Sumy State University 
Structure and Anti-Stokes Luminescence of Yb-containing Glass  
Co-doped with Eu, Ho and Er 
 
V.V. Kouhar1,*, G.E. Malashkevich1, I.A. Khodasevich1, E.V. Pestryakov2 
 
1 B.I. Stepanov Institute of Physics, NAS of Belarus, 68, Nezalezhnastsi Av., 220072 Minsk, Belarus  
2 Institute of Laser Physics, SB RAS, 13/3, Acad. Lavrent’ev Av., 630090 Novosibirsk, Russia 
 
(Received 16 July 2014; revised manuscript received 26 August 2014; published online 29 August 2014) 
 
The aim of our work was synthesis of transparent silicious media high-doped with Yb–Er, Yb–Ho and 
Yb–Eu and determination of the media structure and spectral-luminescent properties in the anti-Stokes 
region at excitation through the Yb3+ ions. 
 
Keywords: Anti-stokes luminescence, Up-conversion, Yb-containing silicious glass, Er3+, Eu3+ and Ho3+ ions. 
 
 PACS numbers: 42.70. – a, 78.55. – m 
 
 
                                                          
* vikusha-kovgar@mail.ru 
1. INTRODUCTION 
 
The Er Yb-containing glasses are extensively used 
as active media of laser operating at   1.55 m [1]. In 
additional, similar media may be used for visualization 
of IR-radiation which is absorbed by Yb3+ ions as well 
as for obtaining of laser effect in their anti-Stokes 
luminescence band. The glassy matrixes which provide 
formation of complex Er Yb centers and characterized 
by an absence in them of oscillators with high vibration 
frequencies are promising for solving of the problems 
indicated above. It is known that the Yb-containing 
phosphors co-activated with certain rare-earth ions are 
widely used for visualization of infrared radiation ab-
sorbed by the Yb3+ ions [2]. A high transparent media 
co-activated by these ions, in principle, may be used as 
active elements of up-conversion lasers. The present 
work problems are the following: preparation of sili-
cious glassy media co-doped with ytterbium, erbium, 
europium, holmium and investigation of their 
structural and spectral-luminescent properties. 
 
2. MATERIALS AND EXPERIMENTAL 
 
The scheme of synthesis of the Yb-containing mate-
rial is given in Fig. 1. The basic source materials were 
tetraethylorthosilicate Si(OC2H5)4 and salts of 
ytterbium, erbium, europium, holmium and buffer 
element. The synthesis method includes tetraethylor-
thosilicate hydrolysis in water solution of hydrochloric 
acid to obtain a sol, preparation of the colloid by adding 
aerosil into the sol, the neutralization of the sol-colloid 
system up to pH  3.0, liquid slip casting, gel-
formation, drying and heat treatment to obtaining of 
monolithic xerogels, impregnation of the xerogels by a 
water-alcohol solution of the rare-earth co-dopes salts, 
subsequent drying, vitrification in air and inertial cool-
ing. 
The structural investigation of synthesized samples 
was carried out by an X-ray diffraction (D8 Advance) 
and scanning electron microscope (LEO-1420REM). 
These samples absorption and luminescence spectra 
were investigated with use of a spectrophotometer 
(Cary 500) and a spectrofluorimeter (SDL-2), respec-
tively. The luminescence decay kinetics were explored 
oscillographicly at excitation by a monopulse laser ra-
diation with  = 266, 380 and 970 nm and t  10 ns. 
 
Si(OC2H5)4, H2O,
C2H5OH AND HCl
HYDROLYSIS
DISPERGATION 
OF AEROSIL
NEUTRALIZATION
CASTING
GELATION
AGING 
IN THE WATER
DRYING
IMPREGNATION
VITRIFICATION
 IN AIR
DRYING
 
 
Fig. 1 – The scheme of synthesis of Yb-containing silicious 
glassy media. 
 
3. RESULTS AND DISCUSSION 
 
All synthesized samples were characterized by a 
high transparence (track of a He-Ne laser ray was 
absent) and with total concentration of the rare-earth 
oxides up to 15 mass %. A containing of OH -groups in 
them was about 0.2 mass %. The phase and 
microscopical analyses showed an absence of obvious 
features of any crystalline particles. This fact permit-
ted us to conclude that the media inhomogeneous are 
lesser than some nm. 
The anti-Stokes luminescence spectra of all samples 
in visible region obtained at excitation by radiation of a 
semiconductor CW laser (  = 970 nm) with a power 
density about 6 kW/cm2 are displayed in Fig. 2. It is 
seen that the spectra of Yb- (Fig. 2a) and Yb–Eu-
 V.V. KOUHAR, G.E. MALASHKEVICH, ET AL. PROC. NAP 3, 02NAESF10 (2014) 
 
 
02NAESF10-2 
containing samples (Fig 2b) are characterized by in-
tense bands caused by cooperative 2(2F5/2  2F7/2) tran-
sitions of Yb3+ pairs (   500 nm) and 5D0  7F2, 7F1 
ones of Eu3+ ions (   613 and 585 nm, respectively). 
Besides of, the luminescence spectrum of Yb–Eu-
containing sample reveals presence of the low intense 
5D1  7F0 (   536 nm) and 5D2  7F0 (   460 nm) 
bands. This later presence testifies to realization of 
successive sensitization of Eu3+ luminescence by the 
paired and isolated Yb3+ ions. The same name spec-
trum of Yb–Er-containing sample is characterized by 
disappearance of the cooperative luminescence band 
and appearance of three relatively intense anti-Stokes 
luminescence bands 2H11/2  4I15/2 (   522 nm), 4S3/2  
4I15/2 (   547 nm) and 4F9/2  4I15/2 (   660 nm) caused 
by Er3+ ions (see Fig. 2c). A disappearance of the Yb3+ 
pairs cooperative luminescence and the relatively high 
intense of anti-Stokes luminescence from the 2H11/2 
level which is located on ~800 cm 1 [3] above the 4S3/2 
one in the Yb–Er-containing media is a worth argu-
ment in a favour of formation of nanocrystalline 
(Yb1 xErx)2O3 particles. Here it should be noted that the 
main feature of Yb–Er-containing glassy media at the 
monopulse excitation is a dramatic dependence of rela-
tive intensity of Er3+ anti-Stokes luminescence bands 
on the Yb3+ excitation power (Fig. 2c, cf. curves 1 and 
2). This fact we explain mainly by essential distinction 
of filling speeds of the corresponding luminescent lev-
els. The spectrum of Yb–Ho-containing sample (Fig. 2d, 
curve 1) is close to spectrum in Fig. 2a. However, the 
difference spectrum of Yb–Ho- and Yb-containing sam-
ples (Fig. 2d curve 2) reveals a weak band at   
480 nm caused by the 5F3  5I8 transition of Ho3+ ions. 
It has been established that a weak up-conversion lu-
minescence of the Yb–Ho-containing sample is caused 
mainly by the back excitations transfer according to the 
Ho3+(5F4  5I6)–Yb3+(2F7/2  2F5/2) scheme. 
The investigation of the samples luminescence de-
cay kinetics showed that the average decay duration of 
the states 2F5/2 (Yb3+), 2H11/2, 4S3/2 and 4F9/2 (Er3+) con-
sists of about 450, 80, 90 and 12 ms, respectively. A 
comparison of the values with the corresponding radia-
tive lifetime testifies to sufficiently high quantum yield 
of the luminescence. In particular, for the Yb-
containing sample it is close to 70%. 
 
4. CONCLUSION 
 
It is shown that the Yb–Ln-containing (Ln = Eu, 
Ho, Er) silicious glassy media are characterized by a 
high transparence and, with the exception of Ln = Ho, 
sufficiently effective anti-Stokes luminescence at 
excitation in the Yb3+ absorption band. These proper-
ties permit us to propose the materials as promising 
active media for visualization of the IR radiation and, 
perhaps, obtaining of laser effect at up-conversion 
pumping. 
 
 
Fig. 2 – Up-conversion luminescence spectra of Yb- (a), Yb–
Eu- (b), Yb–Er- with specific power 3.5×105 (c, curve 1) and 
7×105 (c, curve 2) W/cm2, Yb–Ho-containing (d, curve 1) 
samples, d, curve 2 is difference spectrum of Yb–Ho- and Yb-
containing samples. 
 
AKNOWLEDGEMENTS 
 
This work was partly supported by the Belarusian 
Foundation for Basic Research (grant F12SB-055)  and 
Program of Basic Research SB RAS  NAS of Belarus 
(grant 17).  
 
 
REFERENCES 
 
1. A. Kazanecki, B. Sealy, K. Homewood, S. Ledain, 
W. Jantsch, D. Kuritsyn, Mater. Sci. Eng. 81, 23 (2001). 
2. F. Auzel, Chem. Rev. 104, 139 (2004). 
3. F. Auzel, J. Lumin. 93, 129 (2001). 


Structure and Anti-Stokes Luminescence of Yb-containing Glass Co-doped with Eu, Ho and Er

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Structure and Anti-Stokes Luminescence of Yb-containing Glass Co-doped with Eu, Ho and Er

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