w.sciencedirect.com

J o u rn a l o f R a d i a t i o n R e s e a r c h and A p p l i e d S c i e n c e s 8 ( 2 0 1 5 ) 3 9 9e4 0 3

HOSTED BY Available online at ww

ScienceDirectJournal of Radiation Research and Applied

Sciencesjournal homepage: http : / /www.elsevier .com/locate/ j r ras

Infrared spectroscopy and luminescence spectra ofYb3þ doped ZrO2 nanophosphor

Raunak Kumar Tamrakar a,*, Neha Tiwari b, Vikas Dubey a,Kanchan Upadhyay c

a Department of Applied Physics, Bhilai Institute of Technology (Seth Balkrishan Memorial), Near Bhilai House, Durg,

C.G. 491001, Indiab Department of Physics, Govt. Autonomous Science College, Jabalpur, Indiac Department of Chemistry, Shri Shanakayacharya Vidhyalay Hudco, 490006, India

a r t i c l e i n f o

Article history:

Received 15 December 2014

Received in revised form

21 February 2015

Accepted 27 February 2015

Available online 12 March 2015

Keywords:

ZrO2:Yb3þ

Infrared spectroscopy

Luminescence spectra

Combustion synthesis method

* Corresponding author. Tel.: þ91 982785011E-mail addresses: raunak.ruby@gmail.com

Peer review under responsibility of The Ehttp://dx.doi.org/10.1016/j.jrras.2015.02.0101687-8507/Copyright© 2015, The Egyptian Socopen access article under the CC BY-NC-ND l

a b s t r a c t

The present paper reports infrared spectroscopy and luminescence spectra of Yb3þ doped

ZrO2 nanophosphor. Sample was prepared by combustion synthesis method (CSM) for the

variable concentration of ytterbium. The low temperature synthesis method was suitable

for large scale production present method is an eco-friendly method as well as less time

taking method as compared to other methods. The synthesized samples were character-

ized by X-ray diffraction (XRD) technique; scanning electron microscopy (SEM), trans-

mission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR)

technique. The crystal size was calculated by Scherer's formula. The particle size distri-

bution in prepared sample was determined by SEM and TEM study. The photo-

luminescence spectra was recorded under the 980 nm laser excitation with the variable

concentration of ytterbium. Here the PL intensity increases with increasing the concen-

tration of ytterbium. No concentration quenching were observed. The PL emission spectra

shows intense emission peaks at 987, 998 and 1021 nm all in infrared regions.

Copyright © 2015, The Egyptian Society of Radiation Sciences and Applications. Production

and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license

(http://creativecommons.org/licenses/by-nc-nd/4.0/).

1. Introduction

The research on inorganic luminescence materials having

high efficiency, good thermal and chemical stability has

revealed wide interests from last few decades. The emission

from rare earth ions doped luminescent materials in the op-

tical region of electromagnetic spectrum has been observed

through upconversion (UC) and downconversion (DC) pro-

cesses. Upconversion phosphors have a number of properties

3., raunakphysics@gmail.

gyptian Society of Radiat

iety of Radiation Sciencesicense (http://creativecom

that make them striking for photonics applications such as

display devices, lighting purposes, solar cells, biological ap-

plications, temperature and radiation sensors etc (Pandey and

Rai, 2012; Rai, 2007; Shalav, Richards, & Green, 2007; Singh,

Kumar, & Rai, 2009; Tiwari, Kuraria, & Tamrakar, 2014; Wang

and Liu, 2009).

In up-conversion and down conversion process, the low

phonon energy and high chemical stability are the critical

factors. Low phonon energy can prevent the non-radiative

energy loss with multi-phonon relaxation of rare earth

com (R.K. Tamrakar).

ion Sciences and Applications.

andApplications. Production and hosting by Elsevier B.V. This is anmons.org/licenses/by-nc-nd/4.0/).

J o u r n a l o f R a d i a t i o n R e s e a r c h and A p p l i e d S c i e n c e s 8 ( 2 0 1 5 ) 3 9 9e4 0 3400

dopants and enhance the energy transfer efficiency (Deng,

Wei, Wang, Chen, & Yin, 2011; Tamrakar, Bisen, & Brahme,

2014c; Tamrakar, Bisen & Brahme, 2015; Xia, Luo, Guan, &

Liao, 2012). Besides, the chemical stability is an essential

condition to the solar cells (Xia et al., 2012).

The special electronic configuration of Yb3þ makes the 4f

electrons less shielded than other ions of the lanthanide se-

ries, showing a higher tendency to interact with neighbouring

ions. Such an interaction is not restricted to different ions. It

has been reported that the YbeYb pair interaction produces

visible emission. That is, when there is neither an interme-

diate nor a final energy level (from the codopant) to be popu-

lated in order to emit in the visible.

In this paper, ZrO2:Yb3þ phosphor was prepared by a sim-

ple conventional combustion synthesis technique. The

structural properties of ZrO2:Yb3þ was characterized with X-

ray diffraction, Fourier transform infrared spectroscopy and

field emission scanning electron microscopy. Under excita-

tion with 980 nm laser, three NIR emission bands were

observed. The probable energy transfer mechanism is also

discussed.

Fig. 1 e XRD pattern of ZrO2:Yb3þ (4e16 mol%) phosphor.

2. Experimental

The starting reagents are high purity Zr(NO3)2, Yb(NO3)3$6H2O

and urea. Precursor materials were weighed in stoichiometric

ration and dissolved inminimumquantity of deionizedwater.

Then urea was added in this solution with molar ratio of urea

to nitrates based on total oxidizing and reducing valencies of

oxidizer and fuel (urea) according to concept used in propel-

lant chemistry. Finally the beaker containing solution was

placed into a preheated furnace maintained at 600 �C. Thematerial underwent rapid dehydration and foaming followed

by decomposition, generating combustible gases. These vol-

atile combustible gases ignite and burn with a flame yielding

voluminous solid. Urea was oxidized by nitrate ions and

served as a fuel for propellant reaction. The powders obtained

were then further calcined at 600 �C for 3 h to increase the

luminescence efficiency (Ekambaram & Patil, 1997; Tamrakar,

Bisen, & Brahme, 2014b; Tamrakar, Bisen, and Sahu, 2014;

Tamrakar, Bisen, Sahu, & Brahme, 2014b; Tamrakar, Bisen,

Upadhyay, & Brahme, 2014).

The XRD measurements were carried out using Bruker D8

Advance X-ray diffractometer. The X-rays were produced

using a sealed tube and the wavelength of X-ray was 0.154 nm

(Cu Ka). The X-rays were detected using a fast counting de-

tector based on Silicon strip technology (Bruker Lynx Eye de-

tector). (Dubey, Kaur, Agrawal, Suryanarayana, Murthy, 2013;

Dubey, Suryanarayana, Kaur, 2010; Dubey, Kaur, & Agrawal,

2013; Tamrakar, Bisen, Sahu and Bramhe, 2014a; Tamrakar,

Upadhyay, Bisen, 2014; Tamrakar, Bisen, Upadhyay and

Tiwari, 2014) Observation of particle morphology was inves-

tigated by FEGSEM (field emission gun scanning electron mi-

croscope) (JEOL JSM-6360). The photoluminescence (PL)

emission and excitation spectra were recorded at room tem-

perature by use of a Shimadzu RF-5301 PC spectro-

fluorophotometer (Tamrakar, Bisen, & Bramhe,et al 2014c;

Tamrakar, Bisen, & Upadhyay, 2015, Tamrakar, Kowar,

Uplop, & Robinson,et al 2014; Tamrakar, Tiwari, Kuraria,

Dubey, & Upadhyay, 2014).

3. Results and discussion

3.1. XRD results

The XRD pattern of the sample is shown in Fig. 1. The XRD

pattern recorded for variable concentration of Yb3þ (4 mol%e

16 mol%). The width of the peak increases as the size of the

particle decreases. The size of the particle has been computed

from the full width halfmaximum (FWHM) of the intense peak

using Scherer's formula (Dubey, Tiwari, Tamrakar, Rathore,

and Chitrakat, 2014; Kiryanov et al., 2003; Tamrakar, 2012,

2013; Tamrakar, Bisen, and Brahme, 2014a; Tamrakar et al.,

2013). Particle size of sample is found around 8e13 nm. For-

mula used for calculation is

D ¼ 0:9lb cos q

Here D is particle size

b is FWHM (full width half maximum)

l is the wavelength of X ray source

q is angle of diffraction

3.2. SEM analysis

The morphology of the prepared sample was determined by

using SEM analysis technique. Form SEM image of the sample it

canbeseen that thephosphorhasnano-sphere likemorphology

(Fig. 2). The diameter of the sample is about to 11 nm. The pre-

pared sample shows good phosphor particles have a spherical

shape. Indeed, phosphor particles with a spherical shape

minimize light scattering on their surfaces and therefore,

improve the efficiency of light, emission and the brightness of

such phosphor (Boukerika & Guerbous, 2014; Devaraju, Yin, &

Sato, 2009; Tamrakar, Bisen, Sahu, & Brahme, 2014a)

Fig. 2 e SEM micrographs of ZrO2:Yb3þ (4 mol%) phosphor.

Fig. 4 e PL emission spectra of ZrO2:Yb3þ (4e20 mol%)

phosphor.

J o u rn a l o f R a d i a t i o n R e s e a r c h and A p p l i e d S c i e n c e s 8 ( 2 0 1 5 ) 3 9 9e4 0 3 401

3.3. FTIR spectra

The phase formation and purity of the products are further

confirmed by FTIR spectroscopy, and results are shown in

Fig. 3. The strong transmittance peak 545 cm�1 is ascribed to

the stretching vibration of the ZreO bond. Like the PXRD re-

sults discussed earlier, FT-IR studies further confirms the

formation of pure ZrO2 product with no other major impu-

rities or secondary phases. Similarly the peak at 428 cm�1

ascribed the ZreO vibration (Sheetal et al., 2014; Wang et al,

2006).

3.4. Infrared PL spectra for luminescence study

The emission spectrum of ZrO2:Yb3þ phosphor at room tem-

perature was recorded. The emission spectra of phosphor

were found in near infrared region (NIR) (Fig. 4). The NIR

spectrum of ZrO2: Yb3þ phosphors have emission peaks at

1021 nm, 998 nm and 987 nm. The emission peak at 1021 nm is

the intense band whereas the other two emission peaks at

998 nm and 987 nm are comparatively smaller. The NIR

emission peaks are due to the transitions between the 2F7/2

Fig. 3 e FTIR spectra for ZrO2:Yb3þ (1e4 mol%) phosphor.

excited state and the 2F5/2 ground state for Yb3þ in ZrO2. The

two energy states splits into seven stark levels, 1 to 4 levels for

the ground 2F5/2 and 5-7 levels for 2F7/2 excited state. The

intense peak at 1021 nmattributed to the transition from stark

level 5/ 1, the peaks at lowerwavelength 998 nm and 987 nm

are due to transition 6 / 1 and 5 / 4 respectively (Fig 5).

The emission spectra was recorded as a function of Yb3þ

concentration from 4 to 20 mol% of Yb3þ concentration. No

emission was observed up to 4 mol% of Yb3þ in NIR region

above this concentration. The NIR emission due to Yb3þ ion

increases with increasing Yb3þ ion concentration. No con-

centration quenching observed for NIR emission upto 20mol%

Yb3þ ion concentration (Ermeneux et al 1997; Kiryanov et al.

2002; Montoya, Bausa, Schaudel, & Goldner, 2001; Nakazawa,

1979; Pandey et al., 2013; Tamrakar, Bisen & Bramhe, 2015;

Tamrakar, Bisen, Robinson, Sahu, & Brahme, 2014).

4. Conclusion

The ZrO2:Yb3þ phosphor has been prepared by using con-

ventional combustion synthesis method. The prepared

Fig. 5 e Energy level diagram for the NIR transitions.

J o u r n a l o f R a d i a t i o n R e s e a r c h and A p p l i e d S c i e n c e s 8 ( 2 0 1 5 ) 3 9 9e4 0 3402

phosphor was characterized by using powder XRD, SEM, FTIR

and TEM analysis method. For optical characterization of the

prepared phosphor emission spectra of the phosphors were

recorded. The emission spectra consists peaks in NIR region.

The NIR emission peaks are due to transition between 2F7/

2e2F5/2 states of Yb

3þ ion. The emission spectra were recorded

as a function of Yb3þ ion concentration. It was observed that

no concentration quenching were observed for with 5 mol%

concentrations of Yb3þ ion.

r e f e r e n c e s

Boukerika, A., & Guerbous, L. (2014). Annealing effects onstructural and luminescence properties of red Eu3þ-dopedY2O3 nanophosphors prepared by solegel method. Journal ofLuminescence, 145, 148e153.

Deng, K., Wei, X., Wang, X., Chen, Y., & Yin, M. (2011). Near-infrared quantum cutting via resonant energy transfer fromPr3þ to Yb3þ in LaF3þ. Applied Physics B, 102, 555.

Devaraju, M. K., Yin, S., & Sato, T. (2009). Solvothermal synthesis,controlled morphology and optical properties of Y2O3:Eu

3þ

nanocrystals. Journal of Crystal Growth, 311, 580.Dubey, V., Kaur, J., & Agrawal, S. (2013). Synthesis and

characterization of Eu3þ doped Y2O3 phosphor. Research onChemical Intermediates (Springer), 39(5). http://dx.doi.org/10.1007/s11164-013-1201-5.

Dubey, V., Kaur, J., Agrawal, S., Suryanarayana, N. S., &Murthy, K. V. R. (2013). Synthesis and characterization of Eu3þ

doped SrY2O4 phosphor. Optik e International Journal for Lightand Electron Optics. http://dx.doi.org/10.1016/j.ijleo.2013.03.153.

Dubey, V., Suryanarayana, N. S., & Kaur, J. (2010). Kinetics of TLglow peak of Limestone from Patharia of CG Basin (India).Journal of Minerals Materials Characterization and Engineering,9(12), 1101e1111.

Dubey, V., Tiwari, R., Tamrakar, R. K., Rathore, G. S., &Chitrakat, S. (2014). Infrared spectroscope and upconversionluminescence behaviour of Erbium doped Ytterbium (III), oxidephosphor. dx.doi.org/10.1016/j.infrared.2014.09.014.

Ekambaram, S., & Patil, K. C. (1997). Synthesis and properties ofEu2þ activated blue phosphors. Journal of Alloys and Compounds,248, 7.

Ermeneux, v, Goutaudier, C., Moncorge, R., Cohen-Adad, M. T.,Bettinelli, M., & Cavalli, E. (1997). Growth and fluorescenceproperties of Tm3þ doped YVO4 and Y2O3 single crystals.Optical Materials, 8, 83e90.

Kiryanov, A. V., Aboites, V., Belovolov, A. M., Damzen, M. J.,Minassian, A., Timoshechkinb, M. I., et al. (2003). Journal ofLuminescence, 102e103, 715.

Kiryanov, A. V., Aboites, V., Belovolov, A. M., Timoshechkin, M. I.,Belovolov, M. I., Damzen, M. J., et al. (2002). Powerful visible(530e770 nm) luminescence in Yb,Ho:GGG with IR diodepumping. Optics Express, 10, 832.

Montoya, E., Bausa, L. E., Schaudel, B., & Goldner, P. (2001). Yb3þ

distribution in LiNbO3:(MgO) studied by cooperativeluminescence. Journal of Chemical Physics, 114(7), 3200. http://dx.doi.org/10.1063/1.1342242.

Nakazawa, E. (1979). Charge transfer type luminescence of Yb3þ

ions in RPO4 and R2O2S (R ¼ Y, La, and Lu). Journal ofLuminescence, 18, 272e276. http://dx.doi.org/10.1016/0022-2313(79)90119-4.

Pandey, A., Dey, R., & Rai, V. K. (2013). Sensitization effect of Yb3þ

in upconversion luminescence of Eu3þ codoped Y2O3phosphor. Journal of Physical Chemical & Biophysics, 3, 5.

Pandey, A., & Rai, V. K. (2012). Colour emission tunability inHo3þeTm3þeYb3þcodoped Y2O3 upconverted phosphor.Applied Physics B, 109, 611.

Rai, V. K. (2007). Temperature sensors and optical sensors. AppliedPhysics B, 88, 297e303.

Shalav, A., Richards, B. S., & Green, M. A. (2007). Luminescentlayers for enhanced silicon solar cell performance: up-conversion. Solar Energy Materials and Solar Cells, 91, 829.

Sheetal, Taxak, V. B., Arora, R., Dayawati, & Khatkar, S. P. (Apr.2014). Synthesis, structural and optical properties ofSrZrO3:Eu

3þ phosphor. Journal of Rare Earths, 32(4), 293.Singh, S. K., Kumar, K., & Rai, S. B. (2009).Multifunctional Er3þeYb3þ

codoped Gd2O3nanocrystalline phosphor synthesized throughoptimized combustion route. Applied Physics B, 94, 165.

Tamrakar, R. K. (2012). Studies on absorption spectra of Mn doped CdSnanoparticles. LAP Lambert Academic Pubilshing, VerlAg, ISBN978-3-659-26222-7.

Tamrakar, R. K. (2013). UV-Irradiated thermoluminescencestudies of bulk CdS with trap parameter. Research on ChemicalIntermediates. http://dx.doi.org/10.1007/s11164-013-1166-4.

Tamrakar, R. K., Bisen, D. P., & Brahme, N. (2014a).Characterization and luminescence properties of Gd2O3

phosphor. Research on Chemical Intermediates, 40, 1771e1779.Tamrakar, R. K., Bisen, D. P., & Brahme, N. (2014b). Comparison of

photoluminescence properties of Gd2O3 phosphor synthesizedby combustion and solid state reaction method. Journal ofRadiation Research and Applied Sciences, 7(4), 550e559. http://dx.doi.org/10.1016/j.jrras.2014.09.005.

Tamrakar, R. K., Bisen, D. P., & Brahme, N. (2014c). Influence ofEr3þ concentration on the photoluminescence characteristicsand excitation mechanism of Gd2O3:Er

3þ phosphorsynthesized via a solid-state reaction method. Journal ofLuminescence. http://dx.doi.org/10.1002/bio.2803 (ImpactFactor: 1.27). 11/2014.

Tamrakar, R. K., Bisen, D. P., & Brahme, N. (2015). Effect of Yb3þ

concentration on photoluminescence properties of cubicGd2O3 phosphor. Infrared Physics & Technology, 68(2015), 92e97.

Tamrakar, R. K., Bisen, D. P., Robinson, C. S., Sahu, I. P., &Brahme, N. (2014). Ytterbium doped gadolinium oxide(Gd2O3:Yb

3þ) phosphor: topology, morphology, andluminescence behaviour in Hindawi Publishing Corporation.Indian Journal of Materials Science, 2014, 7. Article ID 396147http://dx.doi.org/10.1155/2014/396147.

Tamrakar, R. K., Bisen, D. P., & Sahu, I. (2014). Structuralcharacterization of combustion synthesized Gd2O3nanopowder by using Glycerin as fuel. Advance Physics Letters.ISSN: 2349-1108, 1(1), 6e9.

Tamrakar, R. K., Bisen, D. P., Sahu, I. P., & Brahme, N. (2014a). UVand gamma ray induced thermoluminescence properties ofcubic Gd2O3:Er

3þ phosphor, 30 July (2014). Journal of RadiationResearch and Applied Sciences, 7(4), 417e429. http://dx.doi.org/10.1016/j.jrras.2014.07.003

Tamrakar, R. K., Bisen, D. P., Sahu, I., & Bramhe, N. (2014b).Raman and XPS studies of combustion route synthesizedMonoclinic phase gadolinium oxide phosphors. AdvancePhysics Letters. ISSN: 2349-1108, 1(1), 1e5.

Tamrakar, R. K., Bisen, D. P., & Upadhyay, K. (2015).Photoluminescence behavior of ZrO2:Eu

3þ with variableconcentration of Eu3þ doped phosphor. Journal of RadiationResearch and Applied Sciences, 8(1), 11e16. http://dx.doi.org/10.1016/j.jrras.2014.10.004.

Tamrakar, R. K., Bisen, D. P., Upadhyay, K., & Bramhe, N. (2014).Effect of fuel on structural and optical characterization ofGd2O3:Er

3þ phosphor. Journal of Luminescence and Applications,1(1), 23e29.

Tamrakar, R. K., Bisen, D. P., Upadhyay, K., & Tiwari, S. (2014).Synthesis and thermoluminescence behavior of ZrO2:Eu

3þ

J o u rn a l o f R a d i a t i o n R e s e a r c h and A p p l i e d S c i e n c e s 8 ( 2 0 1 5 ) 3 9 9e4 0 3 403

with variable concentration of Eu3þ doped phosphor. Journal ofRadiation Research and Applied Sciences. http://dx.doi.org/10.1016/j.jrras.2014.08.006.

Tamrakar, R., Dubey, V., Swamy, S. N., Tiwari, R., Pammi, S. V. N.,& Ramakrishna, P. V. (October 2013). Thermoluminescencestudies of UV-irradiated Y2O3:Eu

3þ doped phosphor. Researchon Chemical Intermediates, 39(8), 3919e3923.

Tamrakar, R. K., Kowar, M. K., Uplop, K., & Robinson, C. S. (2014).Effect of Silver concentration on thermoluminescence studiesof (Cd0.95Zn.05)S phosphors with trap Depth Parameterssynthesized by solid state reaction method. ColumbiaInternational Publishing Journal of Luminescence and Application,1(2), 61e72.

Tamrakar, R. K., Tiwari, N., Kuraria, R. K., Dubey, V., &Upadhyay, K. (2014). Effect of annealing temperatureon thermoluminescence glow curve for UV and gammaray induced ZrO2:Ti phosphor. Journal of Radiation Researchand Applied Sciences. http://dx.doi.org/10.1016/j.jrras.2014.10.005.

Tamrakar, R. K., Upadhyay, K., & Bisen, D. P. (2014). Gamma rayinduced thermoluminescence studies of yttrium (III) oxidenanopowders doped with gadolinium. Journal of RadiationResearch and Applied Sciences. http://dx.doi.org/10.1016/j.jrras.2014.08.012.

Tiwari, N., Kuraria, R. K., & Tamrakar, R. K. (2014).Thermoluminescence glow curve for UV induced ZrO2:Tiphosphor with variable concentration of dopant and variousheating rate. Journal of Radiation Research and Applied Sciences.http://dx.doi.org/10.1016/j.jrras.2014.09.006.

Wang, S. F., Gu, F., Lu, M. K., Yang, Z. S., Zhou, G. J., Jhang, H. P.,et al. (2006). Structural evolution and photoluminescenceproperty of ZrO2:Eu

3þ nano crystal. Optical Material, 28, 122.Wang, F., & Liu, X. (2009). Recent advances in the chemistry of

lanthanide-doped upconversion nanocrystals. Chemical SocietyReviews, 38, 976.

Xia, Z. G., Luo, Y., Guan, M., & Liao, L. B. (2012). Near-infraredluminescence and energy transfer studies of LaOBr:Nd3þ/Yb3þ.Optics Express, 20, A722.