- Email: [email protected]
Spectral characteristics of Er3+ doped magnesium zinc sulfophosphate glasses
Accepted Manuscript 3+ Spectral characteristics of Er doped magnesium zinc sulfophosphate glasses F. Ahmadi, R. Hussin, S.K. Ghoshal PII:
S0925-8388(17)31005-8
DOI:
10.1016/j.jallcom.2017.03.212
Reference:
JALCOM 41250
To appear in:
Journal of Alloys and Compounds
Received Date: 9 January 2017 Revised Date:
9 March 2017
Accepted Date: 20 March 2017
3+ Please cite this article as: F. Ahmadi, R. Hussin, S.K. Ghoshal, Spectral characteristics of Er doped magnesium zinc sulfophosphate glasses, Journal of Alloys and Compounds (2017), doi: 10.1016/ j.jallcom.2017.03.212. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Spectral Characteristics of Er3+ Doped Magnesium Zinc Sulfophosphate Glasses F. Ahmadia, R. Hussina, S. K. Ghoshalb a
Advanced Optical Materials Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia
RI PT
b
Phosphor Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia
*Corresponding author. Email: [email protected]
SC
Abstract
This paper evaluates the spectroscopic properties of the Erbium (Er3+) ions doped magnesium zinc sulfophosphate glass system synthesized via melt-quenching method. Prepared glass samples are characterized using
M AN U
UV-Vis-NIR absorption and photoluminescence (PL) spectroscopy to determine the Er3+ ions concentration dependent spectral characteristics. The absorption spectra displayed nine prominent absorption bands aroused from the the ground state (4I15/2) to the excited state (4I13/2, 4I11/2, 4I9/2, 4F9/2, 2H11/2, 4F7/2, 4F3/2, 2H9/2 and 4G11/2) transitions of Er3+ ion. The intensity parameters (Ω, Ω and Ω ) and radiative properties associated to the spectral transitions of Er3+ ion are calculated using Judd-Ofelt (JO) expressions. Room temperature PL spectra revealed two significant emission bands centered at 541 and 654 nm. Appearance of luminescence intensity quenching beyond 1 mol% of Er3+ is attributed to the cross-relaxation mechanism. The value of stimulated emission cross-section for 4S3/2→4I15/2
TE D
spectroscopic transition in Er3+ ion is found to be very high (85.8211×10-22 cm2). Present glass composition is demonstrated to be advantageous for various photonic applications. Keywords: Sulfophosphate glass, Er3+-doped glass, Hypersensitive transition, Judd-Ofelt parameters, Radiative
1.
Introduction
EP
properties, Energy transfer
AC C
In recent years, optical absorption and luminescence properties of the rare earth ions (REIs) doped borate, silicate, phosphate and tellurite based glasses have been widely investigated. These materials are demanded for various technological and commercial applications including fluorescent display devices, optical detectors, bulk lasers, optical fibers, waveguide lasers and optical amplifiers, optical fibers for telecommunication and the fabrication of new opto-electronic devices [1, 2, 3, 4]. Generally, for developing various optical devices, REIs such as Eu3+, Sm3+, Dy3+, Er3+ and Pr3+ have been exploited [5, 6]. In this regard, selection of good glass host is very crucial to achieve efficient luminescence of REIs. Among oxide glasses, phosphate glasses have received much attention compare to silicate and borate glasses due to their unique characteristics include high transparency, low melting point, high thermal stability, high gain density that is mainly due to high solubility of RE ions besides low refractive index
ACCEPTED MANUSCRIPT
and dispersion [7, 8]. Moreover, sulfate ions shows excellent dissolution in the phosphate glass matrix. Presence of relatively weaker interaction among sulfate and metaphosphate ions achieves dithiophosphate (DPT) units. The occurrence of weak and variable interaction between sulfate and phosphate ions in these glass systems creates ideal environment for incorporating large number of REIs. Thus, high luminescence
RI PT
efficiencies with minimal non-radiative losses are expected to be achievable in this glass system. Among various REIs, Er3+ is used in a broad range of applications including solid state lasers, waveguide lasers and optical amplifiers [9, 10]. Recently, Er3+-doped fiber amplifiers at 1.55 µm received much attention for long distance optical transmission [11, 12, 13]. To achieve high gain per unit fiber
SC
length, the concentration of Er2O3 in the glass must be very high. The emission spectra of Er3+ ion is comprised of many fluorescence lines in the blue, green and red region. Dedicated efforts have been made
M AN U
to achieve excellent luminescence properties of Er3+ ions doped varieties of inorganic glass systems [14, 15, 16, 17]. This REI exhibits eye safe lasing potential with a low threshold action even at room temperature [18] which is suitable for atmospheric communications. Despite many research the lasing potential Er3+ ions activated magnesium zinc sulfophosphate glass system is not explored. This communication reports the spectroscopic properties of magnesium zinc sulfophosphate glasses doped with trivalent erbium (Er3+) ions. Judd-Ofelt (JO) intensity parameters (Ω , where i = 2, 4 and 6) and radiative parameters are evaluated to complement the experimental results on absorption and
TE D
emission properties of the prepared glass system. Furthermore, JO theory is used to calculate the radiative properties such as spontaneous emission transition probabilities, radiative lifetimes of the excited state, branching ratios, fluorescence branching ratios and stimulated emission cross-section. Detailed understanding of these parameters allowed us to optimize the best composition of the doped glass system
EP
for further improvement in the lasing properties of specific electronic transitions. The achieved results are compared with those reported in the literature.
Experimental
AC C
2.
Magnesium zinc sulfophosphate glass system with molar composition of (60-x)P2O5-20MgO20ZnSO4-xEr2O3 (x = 0.0, 0.5, 1.0, 1.5 and 2.0 mol% labeled as PZSMEr0.0, PZSMEr0.5, PZSMEr1.0, PZSMEr1.5 and PZSMEr2.0, respectively) were synthesized by melt-quenching method. Analytical grade powders (from Aldrich chemicals with 99.9% purity) of P2O5, MgO, ZnSO4.7H2O and Er2O3 were acquired as basic constituents for glass preparation. These powders were completely ground using an agate mortar, homogeneously mixed, placed in alumina crucible, and then heated inside a high temperature furnace at 1100 oC for 1 hour 30 min. Thereafter, the transparent melt was poured into a
ACCEPTED MANUSCRIPT
preheated stainless steel mould before being annealed in a second furnace at 300o C for 3 hours. Then, the molten mixture was allowed to cool down to the ambient temperature by switching off the furnace. To get highly transparent surfaces needed for the optical measurements, the obtained samples were cut and polished. Absorption spectra of the polished samples in the range of 320-1640 nm were measured using a
RI PT
Shimadzu UVPC-3101 spectrophotometer. Emission spectra in the range of 500-800 nm (with 476 nm wavelength excitations) were recorded using Jasco spectrofluorometer FP-8500 photoluminescence spectrometer. All measurements were carried out at room temperature. The data in the UV-Vis absorption edge was used to calculate the energies for optical band gap. These band gap energies are further incorporated into the Dimitrov and Sakka's relation [19] to theoretically obtain the values of glass
Theoretical formalism
3.1
Judd-Ofelt parameters
M AN U
3.
SC
refractive index ( ).
The experimental ( ) and calculated ( ) oscillator strengths are obtained via the expression [20, 21]:
TE D
=
=
*
= 4.318 × 10()
+, -./
0
1 . )1
23 + 23 5
(1)
(2)
EP
where 6 is the Avogadro’s number, is the molar absorptivity of the band at a wavenumber (cm-1),
7 is the electronic charge, is the refractive index, 8 is the velocity of light in vacuum, 9 is the electron 1 . )1
is the Lorentz local field correction (accounts for the dipole-dipole transition), and : is the
AC C
mass,
total angular momentum of the ground state. The expressions for electric dipole (23 ) and magnetic dipole (23 ) line strengths yield:
23 = 7 ∑<=,, Ω >< 2, @ :AB A 2 C , @C :C >> 23 =
ℏ >< /
2, @ :A@FG + 22GA 2 C , @C :C >>
(3) (4)
ACCEPTED MANUSCRIPT
where AB A (I = 2, 4 and 6) are known as the reduced matrix elements which do not change from host
to host, Ω (I = 2, 4 and 6) are the JO parameters which can be evaluated by a least-square fit of experimental oscillator strengths to the calculated one. The root-mean-square deviation (JKL ) between
JKL = 0
∑ MNOP (MQRS T(
5
RI PT
the and is given by:
(5)
where U is the number of transitions and V is the number of parameters to be determined. Radiative properties
SC
3.2
The radiative transition probability (W) for the emission transition X: → X C :C is given by the
M AN U
following JO expression:
Y
W X:, X C :C = W3 + W3 = +,Z -./ [
\1 .] )1
23 + 23 ^
(6)
TE D
The radiative lifetime _` of an excited level (X C :C ) is expressed as [22]: _` = [W b X: ](/
(7)
where W b X: is the total radiative transition probability for an excited level which can be obtained by the
EP
sum of the W X: → X C :C terms calculated over all the terminal levels.
AC C
The fluorescence branching ratio d` corresponding to the emission from an excited level (X C :C )
to a lower level (X:) yields [22]: d` X:, X C :C =
e\f-,fg -g ] eh f-
(8)
The measured values of the branching ratios can be found from the relative areas under the emission peaks. The stimulated emission cross-section (ijk ) is written by [23]:
ACCEPTED MANUSCRIPT
ik =
,YP e\f-,fg -g ] *1 ∆,Nmm
(9)
where c is the velocity of light, n is the peak emission wavelength and ∆nMM =
/
oP
p n n is the
Results and discussion
4.1
Absorption spectra and bonding parameters
SC
4.
RI PT
effective emission bandwidth with p as the peak intensity of the luminescence corresponding to n [24].
Fig. 1 shows the room temperature absorption spectra of (60.0-x)P2O5-20.0MgO-20.0ZnSO4xEr2O3 (x = 0.0, 0.5, 1.0, 1.5 and 2.0 mol%) glass samples in the wavelength range of 320-1640 nm. As
M AN U
expected, no significant peaks are observed in the un-doped glass sample. But, Er3+ ions doped glass samples comprised of nine prominent absorption bands which are assigned to the transitions from the ground state (4I15/2) to the excited states (4I13/2, 4I11/2, 4I9/2, 4F9/2, 2H11/2, 4F7/2, 4F3/2, 2H9/2 and 4G11/2) of Er3+ ions [25]. Table 1 enlists the details of these absorption bands together with their aquo values. The position and spectral intensities of certain electric dipole transitions of the REIs that are very sensitive to the environment [26] are commonly termed as hypersensitive transitions. In the present study, among the
TE D
observed transitions, 4I15/2 → 4G11/2 and 4I15/2 → 2H11/2 are classified as the hypersensitive transitions, which
AC C
EP
obeyed the selection rules of ∆S = 0, ∆L ≤ 2 and |∆J| ≤ 2.
ACCEPTED MANUSCRIPT
1.2 4I15/2
Intensity (a.u.)
4G 11/2
4F
2H 9/2
0.6
4F
0.4
7/2
4F
9/2
3/2
0.0 350
400
450
500
550
600
15/2 (b)
0.6 4I
700
PZSMEr0.0 PZSMEr0.5 PZSMEr1.0 PZSMEr1.5 PZSMEr2.0 4I 13/2
4I 11/2
TE D
Intensity (a.u.)
0.8
4I
650
M AN U
Wavelength (nm)
1.0
SC
0.2
RI PT
2H 11/2
(a)
1.0 0.8
PZSMEr0.0 PZSMEr0.5 PZSMEr1.0 PZSMEr1.5 PZSMEr2.0
9/2
0.4 0.2
EP
0.0
1000
1200
1400
1600
Wavelength (nm)
AC C
800
Fig. 1. Absorption spectra of prepared glass systems in the range of (a) UV-Vis and (b) NIR
The nature of the Er3+-ligand bond is evaluated in terms of nephelauxetic ratios (d) and bonding parameters (J). The nature of the metal-ligand bonding is decided by the sign of J where the positive sign corresponds to the covalent nature and the negative sign signifies the ionic nature of Er3+-ligand bond. The relation between d and J follows [27, 28]: t /(s u t s
J=r
(10)
ACCEPTED MANUSCRIPT
w where d̅ is the average value of d and d = Q with x and x are the energies of the corresponding wR
transitions in the complex and aquo-ion, respectively [29]. The values of d and J for studied glass system are presented in Table 1. It is evident that the Er3+-ligand bond is covalent in nature and the degree of covalent character is altered with the variation of Er3+ ion concentration. The results are in the contrary
RI PT
with the results obtained from JO intensity parameters. Table 1
Comparison of the calculated band positions (cm-1) and bonding parameters (β and δ) of present glass system with
PZSMEr0.5
PZSMEr1.0
4
I15/2 → 4I13/2
6510
6510
4
I15/2 → 4I11/2
10,245
4
I15/2 → 4I9/2
4
PZSMEr1.5
PZSMEr2.0
M AN U
Energy level
SC
reported values
Aqua-ion
[30]
[29]
6510
6690
6600
10,246
10,225
10,224
10,245
10,250
12,500
12,500
12,500
12,500
12,525
12,400
I15/2 → 4F9/2
15,290
15,290
15,290
15,290
15,299
15,250
4
I15/2 → 4S3/2
-
-
-
-
18,367
18,350
4
I15/2 → 2H11/2
19,157
19,157
19,083
19,083
19,235
19,150
4
I15/2 → 4F7/2
20,491
20,491
20,491
20,491
20,564
20,450
4
I15/2 → 4F5/2
-
-
-
-
-
22,100
4
I15/2 → 4F3/2
22,321
22,222
22,222
22,222
-
22,500
4
I15/2 → 2H9/2
24,630
24,509
24,510
24,630
-
24,550
AC C
EP
TE D
6510
4
I15/2 → 2G9/2
4
I15/2 → 4G11/2
26,315
26,455
26,455
26,455
-
4
I15/2 → 4G9/2
-
-
-
-
-
y
0.9990
0.9985
0.9979
0.9984
1.005
1
δ
0.0999
0.1437
0.2091
0.1557
-0.531
0
26,400
ACCEPTED MANUSCRIPT
4.2. Optical band gap energy (z{|} ) The optical transitions (direct and indirect transitions) and electronic band structure in crystalline and non-crystalline materials can be understood by examining the fundamental absorption edge in the
RI PT
UV-region. In both transitions, electrons in the valence band are raised across the fundamental gap to the conduction band after interacting with the incoming electromagnetic radiation. Although the conduction band is influenced by the glass forming anions, the cations play an indirect but significant role [31]. The absorption coefficient ~ x is calculated from the absorbance (W) using the expression: /
o
e
SC
~ x = r3u ln r o u = 2.303 r3u (11) where W is the absorbance at frequency x, and
is the thickness of the sample. The frequency dependent
M AN U
absorption coefficient as a function of photon energy (ℎx) can be expressed as [31]:
~ x = ℎx − < K (12) +w
where B is a constant, < is the optical energy gap, and r is an index related to direct or indirect
transitions. The values of r for direct and indirect transitions are 1⁄2 and 2, respectively. Based on Eq. (12), optical energy band gaps ( < ) for direct and indirect transitions can be evaluated by extrapolating
TE D
the linear region of the curve to the horizontal axis from the plot of ~ℎx and ~ℎx // as a function of photon energy hv as presented in Fig 2. The optical band gap values for both direct and indirect transitions of Er3+ doped PZSM glasses are obtained. These values are found to be in the range of 4.0925
AC C
(α hv)
2 (eV.cm-1)2
(a)
400
200
0
6 (b)
(α hv)1/2 (eV.cm-1)1/2
600
EP
to 4.5725 eV and 3.2338 to 3.8660 eV for direct and indirect transitions, respectively.
5 4 3 2 1 0
3.6 3.8 4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4
hv (eV)
4.0
4.4
4.8
5.2
hv (eV)
Fig 2. Variation of (a) ~ℎx versus ℎx (b) ~ℎx // versus ℎx for PZSMEr0.5 glass
ACCEPTED MANUSCRIPT
4.3
Oscillator strengths and Judd-Ofelt analysis The intensity of an absorption band is determined by its oscillator strength which can be directly
calculated using the area under the absorption band. In the present study, the JO intensity parameters are obtained by least-square fitting between Eqs. (1) and (2). The values of are obtained using the the
RI PT
values of Ω . The values , and JKL are depicted in Table 2. The values of JKL (×10-6) for
PZSMEr0.5, PZSMEr1.0, PZSMEr1.5 and PZSMEr2.0 glass are discerned to be 0.687, 0.785, 0.583 and 0.464, respectively. These small values of JKL indicates the excellent correspondence between and
Table 2
SC
.
Experimental and calculated oscillator strengths (×10-6) of synthesized glass system PZSMEr1.0
|
|
PZSMEr1.5
M AN U
PZSMEr0.5 Energy level
PZSMEr2.0
|
|
I15/2 → 4I13/2
1.7541
1.990
1.8658
2.110
1.8105
1.980
1.3215
1.460
4
I15/2 → 4I11/2
1.5496
1.010
1.5734
1.010
1.4322
0.934
1.0541
0.689
4
I15/2 → 4I9/2
0.8113
1.010
0.7593
0.947
0.8342
0.847
0.5859
0.631
4
I15/2 → 4F9/2
4.9284
4.860
4.8159
4.750
4.3525
4.320
3.2337
3.200
4
I15/2 → 2H11/2
21.8383
21.500
18.5320
17.800
15.3333
14.800
11.5472
11.100
4
I15/2 → 4F7/2
4.0655
3.410
4.1995
3.560
3.6926
3.330
2.7663
2.450
4
I15/2 → 4F3/2
1.7433
0.451
1.8107
0.500
1.5189
0.481
1.1689
0.352
4
I15/2 → 2H9/2
1.3452
1.090
1.3810
1.180
1.2588
1.120
0.9430
0.824
4
I15/2 → 4G11/2
37.7690
38.200
30.8750
31.700
25.7823
26.300
19.3151
19.800
EP 0.687
0.785
0.583
0.464
AC C
(×10-6)
TE D
4
Table 3 compares the JO intensity parameters and the spectroscopic quality factor of the present
glass system with related findings in the literature. The JO intensity parameters provides valuable information regarding the glass structure and transition rate of the RE ion energy levels. The change in covalency, structure and symmetry of the Er3+ ion to the surrounding ligand field is characterized using the JO parameter Ω [32]. Conversely, the JO intensity parameters Ω and Ω denotes the viscosity and the dielectric properties of the glass matrix that are influenced by the vibrionic transitions of the Er3+ ions bound to the ligand atoms [33, 34]. As depicted in Table 3, the intensity parameters for the present glass
ACCEPTED MANUSCRIPT
system follows the trend of Ω > Ω > Ω . The large value of Ω for PZSMEr0.5 glass indicates the stronger asymmetry of the site occupied by Er3+ ion than the glass system such as phosphate [25], fluorophosphate [35], NZLE0 [36], TZL [37], GN [37], PBA [37], SAL [37], phosphate [38], borotellurite [39], telluro-fluoroborate [30], and TeO2-ZnO-Li2O [40] except for lithium tetraborate [41],
RI PT
and phosphate [42]. The PZSMEr0.5 glass sample has the maximum value of Ω which signifies strong covalent bonding at optimum doping level [43]. Table 3
Ω
Ω
Ω
PZSMEr0.5
11.16
3.95
1.37
PZSMEr1.0
9.14
3.77
PZSMEr1.5
7.50
PZSMEr2.0
χ
Reference
Ω > Ω > Ω
2.88
Present work
1.56
Ω > Ω > Ω
2.42
Present work
3.37
1.50
Ω > Ω > Ω
2.24
Present work
5.63
2.50
1.10
Ω > Ω > Ω
2.28
Present work
Phosphate
3.79
0.13
1.21
Ω > Ω > Ω
0.11
[25]
Fluorophosphate
2.91
1.63
1.26
Ω > Ω > Ω
1.29
[35]
Phosphate NZLE0 TZL
PBA
1.52
1.11
Ω > Ω > Ω
1.37
[35]
3.91
1.97
2.57
Ω > Ω > Ω
0.76
[36]
5.34
1.75
0.94
Ω > Ω > Ω
1.86
[37]
5.72
0.91
0.32
Ω > Ω > Ω
2.84
[37]
4.67
1.37
0.77
Ω > Ω > Ω
1.78
[37]
5.59
1.42
0.87
Ω > Ω > Ω
1.63
[37]
AC C
SAL
6.65
EP
GN
M AN U
Trend
TE D
Glass Code
SC
Comparison of JO parameters (× 10( cm2) of the present glass system with others (NZLE0: 74.5NaH2PO420ZnO-5Li2CO3-0.5Er2O3; TZL: 70TeO2-25ZnO-5La2O3-0.01Er2O3; GN: 75GeO2-25Na2O-0.01Er2O3; PBA: 65SiO2-25Al2O3-10La2O3-0.01Er2O3; SAL: 55P2O5-40BaO-5Al2O3-0.01Er2O3).
Phosphate
4.05
0.97
0.94
Ω > Ω > Ω
1.03
[38]
TeO2-ZnO-Li2O
6.56
1.6
1.44
Ω > Ω > Ω
1.11
[40]
Borotellurite
4.871
2.621
2.483
Ω > Ω > Ω
1.05
[39]
Telluro-fluoroborate
1.774
0.277
0.699
Ω > Ω > Ω
0.400
[30]
Lithium tetraborate
12.07
2.40
3.87
Ω > Ω > Ω
0.62
[41]
Phosphate
11.37
2.68
2.45
Ω > Ω > Ω
1.09
[42]
ACCEPTED MANUSCRIPT
Fig. 3 illustrates the Er3+ ion concentration dependent variation of the spectroscopic quality factor as well as Ω , Ω , and Ω . The spectroscopic quality factor ( = Ω ⁄Ω ) is used to describe the strength of stimulated emission strengths of Er3+ ions in the host glass matrix. In this work, the decreasing trend of quality factor with increasing Er3+ ion concentration up to 1.5 mol% is observed. The Ω parameter
RI PT
revealed the highest sensitiveness to the environment as compared to Ω and Ω . Furthermore, the Ω and
Ω parameters displayed a monotonic variation as a function of Er3+ ion contents, indicating a low sensitivity to the environmental change of Er3+ ion. Amongst all synthesized glasses, PZSMEr0.5 sample
SC
Ω2 Ω4
3
Ω6 Ω4/Ω6
8 6 4 2
M AN U
10
0 0.0
0.5
1.0
1.5
2.0
2
1
Quality Factor
12
TE D
Intensity Parameters (×10-20 cm2)
exhibited highest value of Ω , implying its strongest Er-O covalency and highest asymmetry.
0 2.5
Er2O3 Concentration (mol%)
Luminescence properties
AC C
4.4
EP
Fig. 3. Er2O3 ions concentration dependent variation of JO intensity parameters and quality factor
Fig. 4 displays the room temperature luminescence spectra of all glass samples under 476 nm
excitations. Un-doped sample did not reveal any significant emission peak as expected. However, Er3+ ions doped glass samples exhibited two prominent peaks centered at about 654 nm (red) and 541 nm (green), which are assigned to the transition from the excited states (4F9/2 and 4S3/2) to the ground state (4I15/2) of Er3+ ion, respectively. The peak positions and their assignments are listed in Table 4. Furthermore, the PL intensity displayed slight enhancement with increasing concentration of Er3+ up to 1.0 mol% and quenched beyond this concentration.
ACCEPTED MANUSCRIPT
800 PZSMEr1.0
RI PT
PZSMEr1.5
400 PZSMEr0.5 PZSMEr0.0 PZSMEr2.0
200
0 600
700
SC
Intensity (a.u.)
600
800
M AN U
Wavelength (nm)
Fig. 4. Luminescence spectra of the Er3+ doped magnesium zinc sulfophosphate glasses Table 4
Er3+ ions contents dependent emission peak positions (nm) and their assignments
S3/2→4I15/2
4
F9/2→4I15/2
PZSM Er1.0
PZSM Er1.5
PZSM Er2.0
541.0
542.0
541.0
541.0
653.5
654.5
654.0
653.5
EP
4
PZSM Er0.5
TE D
Transition
Fig. 5 displays the variation in the PL peak intensity for all transitions as a function of Er3+ ion concentration. It is evident that the peak intensity of 4S3/2→4I15/2 transition revealed the highest value
AC C
irrespective of Er2O3 doping concentration. Besides, the emission intensities are quenched for Er2O3 doping contents more than 1.0 mol%.
ACCEPTED MANUSCRIPT
600
4 S3/2
4 I15/2
4 F9/2
4 I15/2
RI PT
Peak Intensity (a.u.)
800
200
0 0.0
0.5
1.0
SC
400
1.5
2.0
M AN U
Er2O3 Concentration (mol%)
Fig. 5. Er2O3 concentration dependent variation of PL peak intensity for prepared glass systems.
Partial energy level diagram of the Er3+ ions (Fig. 6) is used to describe the emission mechanism. Excitation at 476 nm promotes the Er3+ ion from 4I15/2 to 4F7/2 level where the multi-phonon non-radiative
TE D
decays allow populating both (2H11/2 + 4S3/2) and 4F9/2 excited states, thereby produce green and red emission. The reduction in the green emission intensity with increasing the erbium content can be correlated to cross-relaxation (CR) process between two neighboring RE ions. Generally, the CR mechanism is more probable at higher concentration of the RE ions when the ion-ion distances are short enough. Conversely, the CR decays such as (4S3/2, 4I15/2)-(4I9/2, 4I13/2) and (4F9/2, 4I15/2)-(4I11/2, 4I13/2) are
AC C
EP
responsible for the quenching of green luminescence band.
M AN U
SC
RI PT
ACCEPTED MANUSCRIPT
Fig. 6. Partial energy level diagram of Er3+ ion.
Table 5 enlists the values of calculated magnetic W3 and electric W3 transition probability, radiative lifetime (_` ) and branching ratios (d` ) corresponding to the transition from the upper manifold states, 4I13/2, 4I11/2, 4I9/2, 4F9/2, 4S3/2, 2H11/2, and 4F7/2 to their corresponding lower-lying manifold states.
TE D
Table 6 summarizes the calculated values of the radiative properties of the present glass system including the transition probability (W), radiative lifetime _` ), peak stimulated emission cross-section ik and
branching ratio d` . Irrespective of Er2O3 ion concentration, the transition of 4S3/2→4I15/2 for each glass
revealed highest emission cross-section. The values of ik for 4S3/2→4I15/2 transition are found to be
AC C
glasses, respectively.
EP
81.5311, 85.8211, 81.3811 and 63.0042 for PZSMEr0.5, PZSMEr1.0, and PZSMEr1.5 and PZSMEr2.0
ACCEPTED MANUSCRIPT
Table 5 Values of the energy difference ∆ , W3 (s-1) and W3 (s-1), d (%) and _` (ms) for the prepared glass system. Transition
Wavenumber
(s )
(s )
-1
-1
y (%)
(ms)
RI PT
(cm-1) PZSMEr0.5 I13/2→4I15/2
6,510
0.0195
0.1173
1.4316
209.3994
50.5151
100.00
4
I11/2→4I13/2
3,732
0.0331
0.1708
1.0864
44.11305
11.2853
15.2028
I15/2
10,245
0.0282
0.0003
0.3953
308.9972
0.0000
84.7972
I9/2→4I11/2
2,255
0.003
0.0674
0.1271
2.1850
4
I13/2
5,990
0.0004
0.0106
0.7162
88.8099
4
I15/2
12,500
0.0000
0.1732
0.0099
548.0090
F9/2→4I9/2
2,790
0.1279
0.0059
0.0281
4
I11/2
5,045
0.0704
0.0112
4
I13/2
8,780
0.0101
0.1533
4
I15/2
15,290
0.0000
0.5354
S3/2→4I9/2
5,850
0.0000
0.0788
4
I11/2
8,105
0.0000
0.0042
4
I13/2
11,840
0.0000
4
I15/2
18,350
H11/2→4F9/2
3,867
4
I9/2
6,657
4
I11/2
8,912
4
I13/2
4
I15/2
2
0.0000
13.8632
0.0000
85.5441
13.0060
3.4931
0.3810
1.2839
133.6832
7.9266
3.2705
0.0714
222.1250
0.0000
5.1299
0.4619
3949.737
0.0000
91.2186
0.2542
132.7452
0.0000
4.6270
0.0739
63.0744
0.0000
2.1985
0.0000
0.3462
791.4615
0.0000
27.5871
0.0000
0.0000
0.2211
1881.6748
0.0000
65.5874
0.3629
0.0224
0.0022
80.2568
0.2687
0.3344
0.2077
0.0662
0.2858
293.7240
0.0000
1.2198
0.0357
0.1382
0.0371
236.0536
127.3626
1.5092
M AN U
4
0.5927
TE D
4
1.6122
EP
4
AC C
4
SC
4
12,647
0.0230
0.0611
0.0527
386.5573
85.1771
1.9591
19,157
0.7125
0.4123
0.0925
22869.9290
0.0000
94.9774
F7/2→4F9/2
5,201
0.0121
0.0342
0.0151
20.5670
0.0000
0.2269
4
I9/2
7,991
0.0163
0.0954
0.4277
293.6211
0.0000
3.2397
4
I11/2
10,246
0.0035
0.2648
0.1515
698.9013
0.0000
7.7114
4
I13/2
13,981
0.0000
0.3371
0.0001
1829.4152
0.0000
20.1852
4
I15/2
20,491
0.0000
0.1468
0.6266
6220.6619
0.0000
68.6367
4
3.8474
2.7443
1.5610
0.2309
0.3486
0.0415
0.1103
ACCEPTED MANUSCRIPT
PZSMEr1.0 I13/2→4I15/2
6,510
0.0195
0.1173
1.4316
216.2515
48.5957
100.00
4
I11/2→4I13/2
3,736
0.0331
0.1708
1.0864
44.1342
10.8565
15.4135
I15/2
10,246
0.0282
0.0003
0.3953
301.7797
0.0000
84.5865
I9/2→4I11/2
2,254
0.003
0.0674
0.1271
2.1127
1.5509
0.6090
4
I13/2
5,990
0.0004
0.0106
0.7162
95.9401
0.0000
15.9475
4
I15/2
12,500
0.0000
0.1732
0.0099
501.9963
0.0000
83.4435
F9/2→4I9/2
2,790
0.1279
0.0059
0.0281
10.3143
3.3603
0.3317
4
I11/2
5,044
0.0704
0.0112
1.2839
132.6725
4
I13/2
8,780
0.0101
0.1533
0.0714
203.4317
4
I15/2
15,290
0.0000
0.5354
0.4619
3764.8422
S3/2→4I9/2
5,850
0.0000
0.0788
0.2542
4
I11/2
8,104
0.0000
0.0042
4
I13/2
11,840
0.0000
4
I15/2
18,350
H11/2→4F9/2
4
4
4
SC
4
3.4034
0.0000
4.9350
0.0000
91.3299
133.4944
0.0000
4.2909
0.0739
67.0856
0.0000
2.1564
0.0000
0.3462
861.7387
0.0000
27.6991
0.0000
0.0000
0.2211
2048.7565
0.0000
65.8536
3,867
0.3629
0.0224
0.0022
63.0899
0.2585
0.3240
I9/2
6,657
0.2077
0.0662
0.2858
245.1996
0.0000
1.2539
4
I11/2
8,911
0.0357
0.1382
0.0371
205.2417
122.5231
1.6761
4
I13/2
12,647
0.0230
0.0611
0.0527
338.8662
81.9406
2.1519
4
I15/2
19,157
0.7125
0.4123
0.0925
18497.8785
0.0000
94.5941
F7/2→4F9/2
5,201
4
I9/2
7,991
4
I11/2
4
I13/2
4
I15/2
TE D
EP
4
0.0121
0.0342
0.0151
17.7907
0.0000
0.1329
0.0163
0.0954
0.4277
288.3997
0.0000
2.1542
AC C
2
M AN U
7.6254
4
2.8029
1.6622
0.2426
0.3214
0.0511
10,245
0.0035
0.2648
0.1515
654.6710
0.0000
4.8901
13,981
0.0000
0.3371
0.0001
1669.5788
0.0000
12.4711
20,491
0.0000
0.1468
0.6266
10757.1763
0.0000
80.3517
0.0747
3.9708
PZSMEr1.5
4
I13/2→4I15/2
6,510
0.0195
0.1173
1.4316
203.3299
48.5059
100.00
4
I11/2→4I13/2
3,736
0.0331
0.1708
1.0864
40.2231
10.8364
15.6436
I15/2
10,246
0.0282
0.0003
0.3953
275.3319
0.0000
84.3564
4
3.7758
RI PT
4
3.0638
ACCEPTED MANUSCRIPT
2,254
0.003
0.0674
0.1271
1.9892
1.5481
0.4770
4
I13/2
5,990
0.0004
0.0106
0.7162
289.5559
0.0000
39.0419
4
I15/2
12,500
0.0000
0.1732
0.0099
448.5617
0.0000
60.4812
F9/2→4I9/2
2,790
0.1279
0.0059
0.0281
8.5106
3.3541
0.3164
4
I11/2
5,044
0.0704
0.0112
1.2839
124.2279
7.6113
3.5153
4
I13/2
8,780
0.0101
0.1533
0.0714
181.6589
0.0000
4.8437
4
I15/2
15,290
0.0000
0.5354
0.4619
3425.0752
0.0000
91.3247
S3/2→4I9/2
5,850
0.0000
0.0788
0.2542
124.2277
0.0000
4.1671
4
I11/2
8,104
0.0000
0.0042
0.0739
64.3187
4
I13/2
11,840
0.0000
0.0000
0.3462
826.8311
4
I15/2
18,350
0.0000
0.0000
0.2211
1965.7649
H11/2→4F9/2
3,867
0.3629
0.0224
0.0022
4
I9/2
6,657
0.2077
0.0662
4
I11/2
8,911
0.0357
0.1382
4
I13/2
12,647
0.0230
0.0611
4
I15/2
19,157
0.7125
0.4123
F7/2→4F9/2
5,201
0.0121
0.0342
4
I9/2
7,991
0.0163
4
I11/2
10,245
4
I13/2
13,981
4
I15/2
20,491
4
SC 0.0000
27.7354
0.0000
65.9400
48.8666
0.2580
0.3034
0.2858
201.5563
0.0000
1.2449
0.0371
175.3799
122.2968
1.8385
0.0527
290.7253
81.7892
2.3008
0.0925
15270.1085
0.0000
94.3124
0.0151
15.4295
0.0000
0.1242
0.0954
0.4277
265.6231
0.0000
2.1387
0.0035
0.2648
0.1515
594.6409
0.0000
4.7877
0.0000
0.3371
0.0001
1489.2722
0.0000
11.9908
0.6266
10055.1282
0.0000
80.9586
0.0805
5.0197
M AN U
2.1575
TE D
2
0.0000
0.1468
I13/2→4I15/2
6,510
0.0195
0.1173
1.4316
150.4551
48.7592
100.00
4
I11/2→4I13/2
3,714
0.0331
0.1708
1.0864
29.8022
10.8930
16.6086
I15/2
10,224
0.0282
0.0003
0.3953
204.3296
0.0000
83.3914
I9/2→4I11/2
2,276
0.003
0.0674
0.1271
1.4801
1.5561
0.7488
4
I13/2
5,990
0.0004
0.0106
0.7162
67.7463
0.0000
16.7088
4
I15/2
12,500
0.0000
0.1732
0.0099
334.6695
0.0000
82.5423
F9/2→4I9/2
2,790
0.1279
0.0059
0.0281
6.4195
3.3716
0.3505
4
4
0.3354
0.0618
PZSMEr2.0
4
4
0.2666
0.0000
EP
4
AC C
4
1.3483
RI PT
I9/2→4I11/2
4
4.0812
2.4664
ACCEPTED MANUSCRIPT
I11/2
5,066
0.0704
0.0112
1.2839
92.1787
7.5610
3.5741
4
I13/2
8,780
0.0101
0.1533
0.0714
135.5099
0.0000
4.8515
4
I15/2
15,290
0.0000
0.5354
0.4619
2548.0250
0.0000
91.2239
S3/2→4I9/2
5,850
0.0000
0.0788
0.2542
92.0854
0.0000
4.1860
4
I11/2
8,126
0.0000
0.0042
0.0739
47.5310
0.0000
2.1606
4
I13/2
11,840
0.0000
0.0000
0.3462
609.9941
0.0000
27.7289
4
I15/2
18,350
0.0000
0.0000
0.2211
1450.2417
0.0000
65.9245
H11/2→4F9/2
3,793
0.3629
0.0224
0.0022
36.8907
0.2594
0.3035
4
I9/2
6,583
0.2077
0.0662
0.2858
151.3500
4
I11/2
8,859
0.0357
0.1382
0.0371
131.3543
4
I13/2
12,573
0.0230
0.0611
0.0527
217.5171
4
I15/2
19,083
0.7125
0.4123
0.0925
F7/2→4F9/2
5,201
0.0121
0.0342
4
I9/2
7,991
0.0163
0.0954
4
I11/2
10,267
0.0035
0.2648
4
I13/2
13,981
0.0000
0.3371
4
I15/2
20,491
0.0000
0.1468
SC
1.2364
122.9354
2.0773
82.2163
2.4485
11498.9941
0.0000
93.9344
0.0151
11.5565
0.0000
0.1254
0.4277
197.1583
0.0000
2.1386
0.1515
443.0258
0.0000
4.8055
0.0001
1111.4549
0.0000
12.0560
7455.8869
0.0000
80.8745
M AN U
0.0000
TE D
4
EP
2
AC C
4
0.6266
0.3580
RI PT
4
0.4546
0.0817
0.1085
ACCEPTED MANUSCRIPT
Table 6 Values of n (nm), ∆nMM (nm), W (s-1), ik (×10-22 cm2) as well as experimental and calculated d` (%) for the prepared glass system. ∆ (nm)
(s ) -1
PZSMEr0.5
4
S3/2→4I15/2
541.5
8.0525
1881.6748
81.5311
4
F9/2→4I15/2
652.5
46.4614
3949.7374
62.5340
4
S3/2→4I15/2
541.5
8.5472
2048.7565
85.8211
4
F9/2→4I15/2
654
42.9001
3764.8422
66.8549
4
S3/2→4I15/2
541
8.6271
1965.7649
4
F9/2→4I15/2
653.5
42.7369
4
S3/2→4I15/2
5420
8.2533
4
F9/2→4I15/2
654.5
42.5183
PZSMEr2.0
65.5874
70.5632
91.2186
30.5246
65.8536
69.4754
91.3299
81.3811
31.0530
65.9400
3425.0751
60.9422
68.9470
91.3247
1450.2417
63.0042
29.7515
65.9245
2548.0249
45.6907
70.2485
91.2239
SC
PZSMEr1.5
y (%) (Cal.)
29.4368
M AN U
PZSMEr1.0
y (%) (Exp.)
z| (×10-22 cm2)
Transition
RI PT
| (nm)
Glass
Among all the samples, PZSMEr1.0 glass displayed the highest emission cross-section for S3/2→4I15/2 transition. The value of ik for PZSMEr1.0 glass (Table 7) is discerned to be comparatively
4
higher than the reported STB0.5E [44], KTFPEr [45], SALSFEr10 [46], TZLF1.0Er [47], LBTAFEr10
TE D
[48] and Soda lime silicate [49] glasses. It can be concluded the 1.0 mol% Er3+ doped magnesium zinc
AC C
EP
sulfophosphate glass is a potential candidate for the fabrication of green laser.
ACCEPTED MANUSCRIPT
Table 7 Values of n (nm), ∆nMM (nm), W (s-1), ik (×10-22 cm2), calculated and experimental d` (%) for the 4S3/2 level under 476 nm excitation of the prepared glass system (STB0.5E: 39.5H3BO3-15TeO2-15SrCO3-10SrF2-10BaCO3-10BaF20.5Er2O3; KTFPEr: 50(NaPO3)6-10TeO2-20AlF3-19RF-1Er2O3; SALSFEr10: 42SiO2-10Al2O3-24LiF-23SrF2-1Er2O; TZLF1.0Er: 59TeO2-20ZnO-20LiF-1Er2O3; LBTAFEr10: 49PbO-30H3BO3-10TiO2-10AlF3-1Er2O3). Transition
| (nm)
∆ (nm)
(s-1)
S3/2→4I15/2
541.5
STB0.5E [44]
4
S3/2→4I15/2
550
9
KTFPEr [45]
4
S3/2→4I15/2
550
16
SALSFEr10 [46]
4
S3/2→4I15/2
545
18.16
2350.30
TZLF1.0Er [47]
4
S3/2→4I15/2
550
16.7
1510
LBTAFEr10 [48]
4
S3/2→4I15/2
547
17.91
Soda lime silicate [49]
4
S3/2→4I15/2
576
22.5
2048.7565
85.8211
30.5246
65.8536
1468
68.5
73
68
1309
40.88
-
67
60.1
-
67.3
27.1
-
66
1279
34.7
-
67
1113
25.5
-
68.5
M AN U
Conclusion
8.5472
TE D
5.
[Present
y (%) (Cal.)
SC
4
PZSMEr1.0 work]
y (%) (Exp.)
z| (×10-22cm2)
RI PT
Glass
A series magnesium zinc sulfophosphate glass with varying concentration of Er2O3 doping were synthesized using conventional melt quenching technique. The spectral properties of Er3+ ions inside the host glass matrix were thoroughly analyzed to determine the feasibility of fabricating photonic devices. The absorption spectra exhibited several prominent peaks and the absorbance strongly depended on the
EP
Er3+ ion contents. The JO theory is used to calculate various radiative parameters which displayed significant improvement with the increasing Er3+ ion contents. The higher oscillator strengths
AC C
authenticated the occurrence of lower site symmetry around the Er3+ ion in the prepared glass system. Furthermore, the appearance of higher oscillator strengths of the hypersensitive transition manifested the lower site symmetry around the Er3+ ion in the glass system. The PL peaks intensities are steadily increased up to 1.0 mol% of Er3+ and decreased thereafter. Among all glasses, PZSMEr1.0 revealed the maximum stimulated emission cross-section for 4F9/2→4I15/2 transition. The magnitudes of the JO intensity parameters following the trend of Ω2 >Ω4 >Ω6 demonstrated a significant increase in the spectroscopic
quality factors. The value of branching ratio as much as 60% is accomplished for 4F9/2→4I15/2 and 4S3/2→ 4
I15/2 transitions. The highest value of _` is observed to be 5.0197 ms for the glass with 2.0 mol% of
Er2O3. The improvement of the spectroscopic features of Er3+ ion through their controlled doping inside
ACCEPTED MANUSCRIPT
the magnesium zinc sulfophosphate glass host is demonstrated. The excellent features of the results suggest that these glass compositions are prospective for diverse photonic applications.
Acknowledgements through Vote 12H42, 13H50 (GUP/RU) and 4F424 (FRGS).
References
P.R. Rao, G.M. Krishna, M. Brik, Y. Gandhi, and N. Veeraiah, Fluorescence features of Sm3+
SC
[1]
RI PT
The authors wish to thank to UTM and Ministry of Higher Education for the financial support
ions in Na2SO4–MO–P2O5 glass system—Influence of modifier oxide, J. Lumin. 131(2) (2011) 212-217.
M. Jayasimhadri, L. Moorthy, S. Saleem, and R. Ravikumar, Spectroscopic characteristics of
M AN U
[2]
Sm3+-doped alkali fluorophosphate glasses, Spectrochim. Acta Mol. Biomol. Spectrosc. 64(4) (2006) 939-944. [3]
I. Hager, R. El-Mallawany, and A. Bulou, Luminescence spectra and optical properties of TeO2– WO3–Li2O glasses doped with Nd, Sm and Er rare earth ions, Physica B: Condensed Matter 406(4) (2011) 972-980.
[4]
A. Agarwal, I. Pal, S. Sanghi, and M. Aggarwal, Judd–Ofelt parameters and radiative properties
[5]
TE D
of Sm3+ ions doped zinc bismuth borate glasses, Opt. Mater. 32(2) (2009) 339-344. Z. Mazurak, S. Bodył, R. Lisiecki, J. Gabryś-Pisarska, and M. Czaja, Optical properties of Pr3+, Sm3+ and Er3+ doped P2O5–CaO–SrO–BaO phosphate glass, Opt. Mater. 32(4) (2010) 547-553. [6]
S. Schweizer, L.W. Hobbs, M. Secu, J.-M. Spaeth, A. Edgar, and G.V. Williams, Photostimulated
449-451.
T. Suratwala, R. Steele, G. Wilke, J. Campbell, and K. Takeuchi, Effects of OH content, water
AC C
[7]
EP
luminescence in Eu-doped fluorochlorozirconate glass ceramics, Appl. Phys. Lett. 83(3) (2003)
vapor pressure, and temperature on sub-critical crack growth in phosphate glass, J. Non-Cryst. Solids 263 (2000) 213-227.
[8]
R. Praveena, V. Venkatramu, P. Babu, and C. Jayasankar, Fluorescence spectroscopy of Sm3+
ions in P2O5–PbO–Nb2O5 glasses, Physica B: Condensed Matter 403(19) (2008) 3527-3534.
[9]
K. Wei, D. Machewirth, J. Wenzel, E. Snitzer, and G. Sigel, Pr3+-doped Ge-Ga-S glasses for 1.3 µm optical fiber amplifiers, J. Non-Cryst. Solids 182(3) (1995) 257-261.
[10]
S. Tanabe, N. Sugimoto, S. Ito, and T. Hanada, Broad-band 1.5 µm emission of Er3+ ions in bismuth-based oxide glasses for potential WDM amplifier, J. Lumin. 87 (2000) 670-672.
ACCEPTED MANUSCRIPT
[11]
H. Chen, M. Leblanc, and G. Schinn, Gain enhanced L-band optical fiber amplifiers and tunable fiber lasers with erbium-doped fibers, Opt. Commun. 216(1) (2003) 119-125.
[12]
K. Thyagarajan and J. Kaur, A novel design of an intrinsically gain flattened erbium doped fiber, Opt. Commun. 183(5) (2000) 407-413. K. Oh, A. Kilian, and T. Morse, Analysis of spectroscopic properties of erbium doped Ta2O5–
RI PT
[13]
Al2O3–SiO2 optical fiber, J. Non-Cryst. Solids 259(1) (1999) 10-15. [14]
H. Inoue, K. Soga, and A. Makishima, Simulation of the optical properties of Er: ZBLAN glass, J. Non-Cryst. Solids 298(2) (2002) 270-286.
[15]
J. Pardo, J. Peña, R. Merino, R. Cases, A. Larrea, and V. Orera, Spectroscopic properties of Er3+
SC
and Nd3+ doped glasses with the 0.8CaSiO3–0.2Ca3(PO4)2 eutectic composition, J. Non-Cryst. Solids 298(1) (2002) 23-31.
S. Jiang, M. Myers, and N. Peyghambarian, Er3+ doped phosphate glasses and lasers, J. Non-
M AN U
[16]
Cryst. Solids 239(1) (1998) 143-148. [17]
Z. Yao, Y. Ding, T. Nanba, and Y. Miura, Compositional dependences of Judd–Ofelt parameters of Er3+ in borosilicate glasses, Phys. Chem. Glasses 40(4) (1999) 179-183.
[18]
E. Chicklis, C. Naiman, R. Folweiler, D. Gabbe, H. Jenssen, and A. Linz, High‐Efficiency Room‐Temperature 2.06‐µm Laser Using Sensitized Ho3+: YLF, Appl. Phys. Lett. 19(4) (1971) 119-121.
V. Dimitrov and S. Sakka, Electronic oxide polarizability and optical basicity of simple oxides. I,
TE D
[19]
J. Appl. Phys. 79(3) (1996) 1736-1740. [20]
V. Rodriguez, I. Martin, R. Alcala, and R. Cases, Optical properties and cross relaxation among Sm3+ ions in fluorzincate glasses, J. Lumin. 54(4) (1992) 231-236. C. Görller-Walrand and K. Binnemans, Spectral intensities of ff transitions, Handbook on the
EP
[21]
physics and chemistry of rare earths 25 (1998) 101-264. [22]
D. Ramteke, A. Balakrishna, V. Kumar, and H. Swart, Luminescence dynamics and investigation
[23]
AC C
of Judd-Ofelt intensity parameters of Sm3+ ion containing glasses, Opt. Mater. 64 (2017) 171-178.
Y. Ratnakaram, S. Babu, L.K. Bharat, and C. Nayak, Fluorescence characteristics of Nd3+ doped
multicomponent fluoro-phosphate glasses for potential solid-state laser applications, J. Lumin. 175 (2016) 57-66.
[24]
M. Weber, D. Ziegler, and C.A. Angell, Tailoring stimulated emission cross sections of Nd3+
laser glass: Observation of large cross sections for BiCl3 glasses, J. Appl. Phys. 53(6) (1982) 4344-4350. [25]
K. Pradeesh, C. Oton, V. Agotiya, M. Raghavendra, and G.V. Prakash, Optical properties of Er3+ doped alkali chlorophosphate glasses for optical amplifiers, Opt. Mater. 31(2) (2008) 155-160.
ACCEPTED MANUSCRIPT
[26]
C.K. Jørgensen and B. Judd, Hypersensitive pseudoquadrupole transitions in lanthanides, Mol. Phys. 8(3) (1964) 281-290.
[27]
V. Sreedhar, N. Vijaya, D. Ramachari, and C. Jayasankar, Luminescence studies on Er3+-doped zincfluorophosphate glasses for 1.53 µm laser applications, J. Mol. Struct. 1130 (2017) 1001-
[28]
RI PT
1008. T. Srihari and C. Jayasankar, Spectral investigations of Sm3+-doped niobium phosphate glasses, Opt. Mater. 66 (2017) 35-42. [29]
W. Carnall, P. Fields, and K. Rajnak, Electronic energy levels in the trivalent lanthanide aquo ions. I. Pr3+, Nd3+, Pm3+, Sm3+, Dy3+, Ho3+, Er3+, and Tm3+, J. Chem. Phys. 49(10) (1968) 4424-
[30]
SC
4442.
P. Karthikeyan, P. Suthanthirakumar, R. Vijayakumar, and K. Marimuthu, Structural and
M AN U
luminescence behaviour of Er3+ doped telluro-fluoroborate glasses, J. Mol. Struct. 1083 (2015) 268-277. [31]
E. Davis and N. Mott, Conduction in non-crystalline systems V. Conductivity, optical absorption and photoconductivity in amorphous semiconductors, Philosophical Magazine 22(179) (1970) 0903-0922.
[32]
S. Tanabe, T. Ohyagi, N. Soga, and T. Hanada, Compositional dependence of Judd-Ofelt parameters of Er3+ ions in alkali-metal borate glasses, Phys. Rev. B 46(6) (1992) 3305. W.F. Krupke, Optical Absorption and Fluorescence Intensities in Several Rare-Earth-Doped Y2O3
TE D
[33]
and LaF3 Single Crystals, Phys. Rev. 145(1) (1966) 325. [34]
G. Lakshminarayana, R. Yang, M. Mao, and J. Qiu, Spectral analysis of RE3+(RE= Sm, Dy, and Tm): P2O5–Al2O3–Na2O glasses, Opt. Mater. 31(10) (2009) 1506-1512. X. Zou and T. Izumitani, Spectroscopic properties and mechanisms of excited state absorption
EP
[35]
and energy transfer upconversion for Er3+-doped glasses, J. Non-Cryst. Solids 162(1) (1993) 6880.
A. Langar, C. Bouzidi, H. Elhouichet, and M. Férid, Er–Yb codoped phosphate glasses with
AC C
[36]
improved gain characteristics for an efficient 1.55 µm broadband optical amplifiers, J. Lumin. 148 (2014) 249-255.
[37]
J. Yang, S. Dai, N. Dai, L. Wen, L. Hu, and Z. Jiang, Investigation on nonradiative decay of
4
[38]
I13/2→ 4I15/2 transition of Er3+-doped oxide glasses, J. Lumin. 106(1) (2004) 9-14.
H. Desirena, E. De la Rosa, L. Diaz-Torres, and G. Kumar, Concentration effect of Er3+ ion on the spectroscopic properties of Er3+ and Yb3+/Er3+ co-doped phosphate glasses, Opt. Mater. 28(5) (2006) 560-568.
ACCEPTED MANUSCRIPT
[39]
M. Azlan, M. Halimah, and H. Sidek, Linear and nonlinear optical properties of erbium doped zinc borotellurite glass system, J. Lumin. 181 (2017) 400-406.
[40]
H. Desirena, E. De la Rosa, A. Shulzgen, S. Shabet, and N. Peyghambarian, Er3+ and Yb3+ concentration effect in the spectroscopic properties and energy transfer in Yb3+/Er3+ codoped
[41]
RI PT
tellurite glasses, J. Phys. D: Appl. Phys. 41(9) (2008) 095102. B. Padlyak, R. Lisiecki, and W. Ryba-Romanowski, Spectroscopy of the Er-doped lithium tetraborate glasses, Opt. Mater. 54 (2016) 126-133. [42]
S.N. Rasool, B. Jamalaiah, K. Suresh, L.R. Moorthy, and C. Jayasankar, Spectroscopic properties of Er3+-doped phosphate based glasses for broadband 1.54 µm emission, J. Mol. Struct. 1130
[43]
SC
(2017) 837-843.
C. Bouzidi, H. Elhouichet, and A. Moadhen, Yb3+ effect on the spectroscopic properties of Er–Yb codoped SnO2 thin films, J. Lumin. 131(12) (2011) 2630-2635.
K. Annapoorani, N.S. Murthy, T. Ravindran, and K. Marimuthu, Influence of Er3+ ion
M AN U
[44]
concentration on spectroscopic properties and luminescence behavior in Er3+ doped strontium telluroborate glasses, J. Lumin. 171 (2016) 19-26. [45]
M. Jayasimhadri, L. Moorthy, K. Kojima, K. Yamamoto, N. Wada, and N. Wada, Er3+-doped tellurofluorophosphate glasses for lasers and optical amplifiers, J. Phys.: Condens. Matter 17(48) (2005) 7705.
C. Kesavulu, V. Sreedhar, C. Jayasankar, K. Jang, D.-S. Shin, and S.S. Yi, Structural, thermal and
TE D
[46]
spectroscopic properties of highly Er3+-doped novel oxyfluoride glasses for photonic application, Mater. Res. Bull. 51 (2014) 336-344. [47]
P. Babu, H.J. Seo, C. Kesavulu, K.H. Jang, and C. Jayasankar, Thermal and optical properties of
[48]
EP
Er3+-doped oxyfluorotellurite glasses, J. Lumin. 129(5) (2009) 444-448. B. Jamalaiah, T. Suhasini, L.R. Moorthy, K.J. Reddy, I.-G. Kim, D.-S. Yoo, and K. Jang, Visible and near infrared luminescence properties of Er3+-doped LBTAF glasses for optical amplifiers,
[49]
AC C
Opt. Mater. 34(5) (2012) 861-867. Y. Sharma, S. Surana, R. Singh, and R. Dubedi, Spectral studies of erbium doped soda lime
silicate glasses in visible and near infrared regions, Opt. Mater. 29(6) (2007) 598-604.
ACCEPTED MANUSCRIPT
Highlights
Erbium (Er3+) ions doped magnesium zinc sulfophosphate glass system prepared by melt-quenching method.
PZSMEr0.5 glass sample showed the largest value of Ωଶ which denotes to the stronger asymmetry of the
RI PT
site occupied by Er3+ ion. There was slight PL intensity enhancement with increasing concentration of Er3+ up to 1.0 mol%.
PZSMEr1.0 glass showed the highest emission cross-section for 4S3/2→4I15/2 transition.
AC C
EP
TE D
M AN U
SC
S0925-8388(17)31005-8
DOI:
10.1016/j.jallcom.2017.03.212
Reference:
JALCOM 41250
To appear in:
Journal of Alloys and Compounds
Received Date: 9 January 2017 Revised Date:
9 March 2017
Accepted Date: 20 March 2017
3+ Please cite this article as: F. Ahmadi, R. Hussin, S.K. Ghoshal, Spectral characteristics of Er doped magnesium zinc sulfophosphate glasses, Journal of Alloys and Compounds (2017), doi: 10.1016/ j.jallcom.2017.03.212. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Spectral Characteristics of Er3+ Doped Magnesium Zinc Sulfophosphate Glasses F. Ahmadia, R. Hussina, S. K. Ghoshalb a
Advanced Optical Materials Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia
RI PT
b
Phosphor Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia
*Corresponding author. Email: [email protected]
SC
Abstract
This paper evaluates the spectroscopic properties of the Erbium (Er3+) ions doped magnesium zinc sulfophosphate glass system synthesized via melt-quenching method. Prepared glass samples are characterized using
M AN U
UV-Vis-NIR absorption and photoluminescence (PL) spectroscopy to determine the Er3+ ions concentration dependent spectral characteristics. The absorption spectra displayed nine prominent absorption bands aroused from the the ground state (4I15/2) to the excited state (4I13/2, 4I11/2, 4I9/2, 4F9/2, 2H11/2, 4F7/2, 4F3/2, 2H9/2 and 4G11/2) transitions of Er3+ ion. The intensity parameters (Ω, Ω and Ω ) and radiative properties associated to the spectral transitions of Er3+ ion are calculated using Judd-Ofelt (JO) expressions. Room temperature PL spectra revealed two significant emission bands centered at 541 and 654 nm. Appearance of luminescence intensity quenching beyond 1 mol% of Er3+ is attributed to the cross-relaxation mechanism. The value of stimulated emission cross-section for 4S3/2→4I15/2
TE D
spectroscopic transition in Er3+ ion is found to be very high (85.8211×10-22 cm2). Present glass composition is demonstrated to be advantageous for various photonic applications. Keywords: Sulfophosphate glass, Er3+-doped glass, Hypersensitive transition, Judd-Ofelt parameters, Radiative
1.
Introduction
EP
properties, Energy transfer
AC C
In recent years, optical absorption and luminescence properties of the rare earth ions (REIs) doped borate, silicate, phosphate and tellurite based glasses have been widely investigated. These materials are demanded for various technological and commercial applications including fluorescent display devices, optical detectors, bulk lasers, optical fibers, waveguide lasers and optical amplifiers, optical fibers for telecommunication and the fabrication of new opto-electronic devices [1, 2, 3, 4]. Generally, for developing various optical devices, REIs such as Eu3+, Sm3+, Dy3+, Er3+ and Pr3+ have been exploited [5, 6]. In this regard, selection of good glass host is very crucial to achieve efficient luminescence of REIs. Among oxide glasses, phosphate glasses have received much attention compare to silicate and borate glasses due to their unique characteristics include high transparency, low melting point, high thermal stability, high gain density that is mainly due to high solubility of RE ions besides low refractive index
ACCEPTED MANUSCRIPT
and dispersion [7, 8]. Moreover, sulfate ions shows excellent dissolution in the phosphate glass matrix. Presence of relatively weaker interaction among sulfate and metaphosphate ions achieves dithiophosphate (DPT) units. The occurrence of weak and variable interaction between sulfate and phosphate ions in these glass systems creates ideal environment for incorporating large number of REIs. Thus, high luminescence
RI PT
efficiencies with minimal non-radiative losses are expected to be achievable in this glass system. Among various REIs, Er3+ is used in a broad range of applications including solid state lasers, waveguide lasers and optical amplifiers [9, 10]. Recently, Er3+-doped fiber amplifiers at 1.55 µm received much attention for long distance optical transmission [11, 12, 13]. To achieve high gain per unit fiber
SC
length, the concentration of Er2O3 in the glass must be very high. The emission spectra of Er3+ ion is comprised of many fluorescence lines in the blue, green and red region. Dedicated efforts have been made
M AN U
to achieve excellent luminescence properties of Er3+ ions doped varieties of inorganic glass systems [14, 15, 16, 17]. This REI exhibits eye safe lasing potential with a low threshold action even at room temperature [18] which is suitable for atmospheric communications. Despite many research the lasing potential Er3+ ions activated magnesium zinc sulfophosphate glass system is not explored. This communication reports the spectroscopic properties of magnesium zinc sulfophosphate glasses doped with trivalent erbium (Er3+) ions. Judd-Ofelt (JO) intensity parameters (Ω , where i = 2, 4 and 6) and radiative parameters are evaluated to complement the experimental results on absorption and
TE D
emission properties of the prepared glass system. Furthermore, JO theory is used to calculate the radiative properties such as spontaneous emission transition probabilities, radiative lifetimes of the excited state, branching ratios, fluorescence branching ratios and stimulated emission cross-section. Detailed understanding of these parameters allowed us to optimize the best composition of the doped glass system
EP
for further improvement in the lasing properties of specific electronic transitions. The achieved results are compared with those reported in the literature.
Experimental
AC C
2.
Magnesium zinc sulfophosphate glass system with molar composition of (60-x)P2O5-20MgO20ZnSO4-xEr2O3 (x = 0.0, 0.5, 1.0, 1.5 and 2.0 mol% labeled as PZSMEr0.0, PZSMEr0.5, PZSMEr1.0, PZSMEr1.5 and PZSMEr2.0, respectively) were synthesized by melt-quenching method. Analytical grade powders (from Aldrich chemicals with 99.9% purity) of P2O5, MgO, ZnSO4.7H2O and Er2O3 were acquired as basic constituents for glass preparation. These powders were completely ground using an agate mortar, homogeneously mixed, placed in alumina crucible, and then heated inside a high temperature furnace at 1100 oC for 1 hour 30 min. Thereafter, the transparent melt was poured into a
ACCEPTED MANUSCRIPT
preheated stainless steel mould before being annealed in a second furnace at 300o C for 3 hours. Then, the molten mixture was allowed to cool down to the ambient temperature by switching off the furnace. To get highly transparent surfaces needed for the optical measurements, the obtained samples were cut and polished. Absorption spectra of the polished samples in the range of 320-1640 nm were measured using a
RI PT
Shimadzu UVPC-3101 spectrophotometer. Emission spectra in the range of 500-800 nm (with 476 nm wavelength excitations) were recorded using Jasco spectrofluorometer FP-8500 photoluminescence spectrometer. All measurements were carried out at room temperature. The data in the UV-Vis absorption edge was used to calculate the energies for optical band gap. These band gap energies are further incorporated into the Dimitrov and Sakka's relation [19] to theoretically obtain the values of glass
Theoretical formalism
3.1
Judd-Ofelt parameters
M AN U
3.
SC
refractive index ( ).
The experimental ( ) and calculated ( ) oscillator strengths are obtained via the expression [20, 21]:
TE D
=
=
*
= 4.318 × 10()
+, -./
0
1 . )1
23 + 23 5
(1)
(2)
EP
where 6 is the Avogadro’s number, is the molar absorptivity of the band at a wavenumber (cm-1),
7 is the electronic charge, is the refractive index, 8 is the velocity of light in vacuum, 9 is the electron 1 . )1
is the Lorentz local field correction (accounts for the dipole-dipole transition), and : is the
AC C
mass,
total angular momentum of the ground state. The expressions for electric dipole (23 ) and magnetic dipole (23 ) line strengths yield:
23 = 7 ∑<=,, Ω >< 2, @ :AB A 2 C , @C :C >> 23 =
ℏ >< /
2, @ :A@FG + 22GA 2 C , @C :C >>
(3) (4)
ACCEPTED MANUSCRIPT
where AB A (I = 2, 4 and 6) are known as the reduced matrix elements which do not change from host
to host, Ω (I = 2, 4 and 6) are the JO parameters which can be evaluated by a least-square fit of experimental oscillator strengths to the calculated one. The root-mean-square deviation (JKL ) between
JKL = 0
∑ MNOP (MQRS T(
5
RI PT
the and is given by:
(5)
where U is the number of transitions and V is the number of parameters to be determined. Radiative properties
SC
3.2
The radiative transition probability (W) for the emission transition X: → X C :C is given by the
M AN U
following JO expression:
Y
W X:, X C :C = W3 + W3 = +,Z -./ [
\1 .] )1
23 + 23 ^
(6)
TE D
The radiative lifetime _` of an excited level (X C :C ) is expressed as [22]: _` = [W b X: ](/
(7)
where W b X: is the total radiative transition probability for an excited level which can be obtained by the
EP
sum of the W X: → X C :C terms calculated over all the terminal levels.
AC C
The fluorescence branching ratio d` corresponding to the emission from an excited level (X C :C )
to a lower level (X:) yields [22]: d` X:, X C :C =
e\f-,fg -g ] eh f-
(8)
The measured values of the branching ratios can be found from the relative areas under the emission peaks. The stimulated emission cross-section (ijk ) is written by [23]:
ACCEPTED MANUSCRIPT
ik =
,YP e\f-,fg -g ] *1 ∆,Nmm
(9)
where c is the velocity of light, n is the peak emission wavelength and ∆nMM =
/
oP
p n n is the
Results and discussion
4.1
Absorption spectra and bonding parameters
SC
4.
RI PT
effective emission bandwidth with p as the peak intensity of the luminescence corresponding to n [24].
Fig. 1 shows the room temperature absorption spectra of (60.0-x)P2O5-20.0MgO-20.0ZnSO4xEr2O3 (x = 0.0, 0.5, 1.0, 1.5 and 2.0 mol%) glass samples in the wavelength range of 320-1640 nm. As
M AN U
expected, no significant peaks are observed in the un-doped glass sample. But, Er3+ ions doped glass samples comprised of nine prominent absorption bands which are assigned to the transitions from the ground state (4I15/2) to the excited states (4I13/2, 4I11/2, 4I9/2, 4F9/2, 2H11/2, 4F7/2, 4F3/2, 2H9/2 and 4G11/2) of Er3+ ions [25]. Table 1 enlists the details of these absorption bands together with their aquo values. The position and spectral intensities of certain electric dipole transitions of the REIs that are very sensitive to the environment [26] are commonly termed as hypersensitive transitions. In the present study, among the
TE D
observed transitions, 4I15/2 → 4G11/2 and 4I15/2 → 2H11/2 are classified as the hypersensitive transitions, which
AC C
EP
obeyed the selection rules of ∆S = 0, ∆L ≤ 2 and |∆J| ≤ 2.
ACCEPTED MANUSCRIPT
1.2 4I15/2
Intensity (a.u.)
4G 11/2
4F
2H 9/2
0.6
4F
0.4
7/2
4F
9/2
3/2
0.0 350
400
450
500
550
600
15/2 (b)
0.6 4I
700
PZSMEr0.0 PZSMEr0.5 PZSMEr1.0 PZSMEr1.5 PZSMEr2.0 4I 13/2
4I 11/2
TE D
Intensity (a.u.)
0.8
4I
650
M AN U
Wavelength (nm)
1.0
SC
0.2
RI PT
2H 11/2
(a)
1.0 0.8
PZSMEr0.0 PZSMEr0.5 PZSMEr1.0 PZSMEr1.5 PZSMEr2.0
9/2
0.4 0.2
EP
0.0
1000
1200
1400
1600
Wavelength (nm)
AC C
800
Fig. 1. Absorption spectra of prepared glass systems in the range of (a) UV-Vis and (b) NIR
The nature of the Er3+-ligand bond is evaluated in terms of nephelauxetic ratios (d) and bonding parameters (J). The nature of the metal-ligand bonding is decided by the sign of J where the positive sign corresponds to the covalent nature and the negative sign signifies the ionic nature of Er3+-ligand bond. The relation between d and J follows [27, 28]: t /(s u t s
J=r
(10)
ACCEPTED MANUSCRIPT
w where d̅ is the average value of d and d = Q with x and x are the energies of the corresponding wR
transitions in the complex and aquo-ion, respectively [29]. The values of d and J for studied glass system are presented in Table 1. It is evident that the Er3+-ligand bond is covalent in nature and the degree of covalent character is altered with the variation of Er3+ ion concentration. The results are in the contrary
RI PT
with the results obtained from JO intensity parameters. Table 1
Comparison of the calculated band positions (cm-1) and bonding parameters (β and δ) of present glass system with
PZSMEr0.5
PZSMEr1.0
4
I15/2 → 4I13/2
6510
6510
4
I15/2 → 4I11/2
10,245
4
I15/2 → 4I9/2
4
PZSMEr1.5
PZSMEr2.0
M AN U
Energy level
SC
reported values
Aqua-ion
[30]
[29]
6510
6690
6600
10,246
10,225
10,224
10,245
10,250
12,500
12,500
12,500
12,500
12,525
12,400
I15/2 → 4F9/2
15,290
15,290
15,290
15,290
15,299
15,250
4
I15/2 → 4S3/2
-
-
-
-
18,367
18,350
4
I15/2 → 2H11/2
19,157
19,157
19,083
19,083
19,235
19,150
4
I15/2 → 4F7/2
20,491
20,491
20,491
20,491
20,564
20,450
4
I15/2 → 4F5/2
-
-
-
-
-
22,100
4
I15/2 → 4F3/2
22,321
22,222
22,222
22,222
-
22,500
4
I15/2 → 2H9/2
24,630
24,509
24,510
24,630
-
24,550
AC C
EP
TE D
6510
4
I15/2 → 2G9/2
4
I15/2 → 4G11/2
26,315
26,455
26,455
26,455
-
4
I15/2 → 4G9/2
-
-
-
-
-
y
0.9990
0.9985
0.9979
0.9984
1.005
1
δ
0.0999
0.1437
0.2091
0.1557
-0.531
0
26,400
ACCEPTED MANUSCRIPT
4.2. Optical band gap energy (z{|} ) The optical transitions (direct and indirect transitions) and electronic band structure in crystalline and non-crystalline materials can be understood by examining the fundamental absorption edge in the
RI PT
UV-region. In both transitions, electrons in the valence band are raised across the fundamental gap to the conduction band after interacting with the incoming electromagnetic radiation. Although the conduction band is influenced by the glass forming anions, the cations play an indirect but significant role [31]. The absorption coefficient ~ x is calculated from the absorbance (W) using the expression: /
o
e
SC
~ x = r3u ln r o u = 2.303 r3u (11) where W is the absorbance at frequency x, and
is the thickness of the sample. The frequency dependent
M AN U
absorption coefficient as a function of photon energy (ℎx) can be expressed as [31]:
~ x = ℎx − < K (12) +w
where B is a constant, < is the optical energy gap, and r is an index related to direct or indirect
transitions. The values of r for direct and indirect transitions are 1⁄2 and 2, respectively. Based on Eq. (12), optical energy band gaps ( < ) for direct and indirect transitions can be evaluated by extrapolating
TE D
the linear region of the curve to the horizontal axis from the plot of ~ℎx and ~ℎx // as a function of photon energy hv as presented in Fig 2. The optical band gap values for both direct and indirect transitions of Er3+ doped PZSM glasses are obtained. These values are found to be in the range of 4.0925
AC C
(α hv)
2 (eV.cm-1)2
(a)
400
200
0
6 (b)
(α hv)1/2 (eV.cm-1)1/2
600
EP
to 4.5725 eV and 3.2338 to 3.8660 eV for direct and indirect transitions, respectively.
5 4 3 2 1 0
3.6 3.8 4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4
hv (eV)
4.0
4.4
4.8
5.2
hv (eV)
Fig 2. Variation of (a) ~ℎx versus ℎx (b) ~ℎx // versus ℎx for PZSMEr0.5 glass
ACCEPTED MANUSCRIPT
4.3
Oscillator strengths and Judd-Ofelt analysis The intensity of an absorption band is determined by its oscillator strength which can be directly
calculated using the area under the absorption band. In the present study, the JO intensity parameters are obtained by least-square fitting between Eqs. (1) and (2). The values of are obtained using the the
RI PT
values of Ω . The values , and JKL are depicted in Table 2. The values of JKL (×10-6) for
PZSMEr0.5, PZSMEr1.0, PZSMEr1.5 and PZSMEr2.0 glass are discerned to be 0.687, 0.785, 0.583 and 0.464, respectively. These small values of JKL indicates the excellent correspondence between and
Table 2
SC
.
Experimental and calculated oscillator strengths (×10-6) of synthesized glass system PZSMEr1.0
|
|
PZSMEr1.5
M AN U
PZSMEr0.5 Energy level
PZSMEr2.0
|
|
I15/2 → 4I13/2
1.7541
1.990
1.8658
2.110
1.8105
1.980
1.3215
1.460
4
I15/2 → 4I11/2
1.5496
1.010
1.5734
1.010
1.4322
0.934
1.0541
0.689
4
I15/2 → 4I9/2
0.8113
1.010
0.7593
0.947
0.8342
0.847
0.5859
0.631
4
I15/2 → 4F9/2
4.9284
4.860
4.8159
4.750
4.3525
4.320
3.2337
3.200
4
I15/2 → 2H11/2
21.8383
21.500
18.5320
17.800
15.3333
14.800
11.5472
11.100
4
I15/2 → 4F7/2
4.0655
3.410
4.1995
3.560
3.6926
3.330
2.7663
2.450
4
I15/2 → 4F3/2
1.7433
0.451
1.8107
0.500
1.5189
0.481
1.1689
0.352
4
I15/2 → 2H9/2
1.3452
1.090
1.3810
1.180
1.2588
1.120
0.9430
0.824
4
I15/2 → 4G11/2
37.7690
38.200
30.8750
31.700
25.7823
26.300
19.3151
19.800
EP 0.687
0.785
0.583
0.464
AC C
(×10-6)
TE D
4
Table 3 compares the JO intensity parameters and the spectroscopic quality factor of the present
glass system with related findings in the literature. The JO intensity parameters provides valuable information regarding the glass structure and transition rate of the RE ion energy levels. The change in covalency, structure and symmetry of the Er3+ ion to the surrounding ligand field is characterized using the JO parameter Ω [32]. Conversely, the JO intensity parameters Ω and Ω denotes the viscosity and the dielectric properties of the glass matrix that are influenced by the vibrionic transitions of the Er3+ ions bound to the ligand atoms [33, 34]. As depicted in Table 3, the intensity parameters for the present glass
ACCEPTED MANUSCRIPT
system follows the trend of Ω > Ω > Ω . The large value of Ω for PZSMEr0.5 glass indicates the stronger asymmetry of the site occupied by Er3+ ion than the glass system such as phosphate [25], fluorophosphate [35], NZLE0 [36], TZL [37], GN [37], PBA [37], SAL [37], phosphate [38], borotellurite [39], telluro-fluoroborate [30], and TeO2-ZnO-Li2O [40] except for lithium tetraborate [41],
RI PT
and phosphate [42]. The PZSMEr0.5 glass sample has the maximum value of Ω which signifies strong covalent bonding at optimum doping level [43]. Table 3
Ω
Ω
Ω
PZSMEr0.5
11.16
3.95
1.37
PZSMEr1.0
9.14
3.77
PZSMEr1.5
7.50
PZSMEr2.0
χ
Reference
Ω > Ω > Ω
2.88
Present work
1.56
Ω > Ω > Ω
2.42
Present work
3.37
1.50
Ω > Ω > Ω
2.24
Present work
5.63
2.50
1.10
Ω > Ω > Ω
2.28
Present work
Phosphate
3.79
0.13
1.21
Ω > Ω > Ω
0.11
[25]
Fluorophosphate
2.91
1.63
1.26
Ω > Ω > Ω
1.29
[35]
Phosphate NZLE0 TZL
PBA
1.52
1.11
Ω > Ω > Ω
1.37
[35]
3.91
1.97
2.57
Ω > Ω > Ω
0.76
[36]
5.34
1.75
0.94
Ω > Ω > Ω
1.86
[37]
5.72
0.91
0.32
Ω > Ω > Ω
2.84
[37]
4.67
1.37
0.77
Ω > Ω > Ω
1.78
[37]
5.59
1.42
0.87
Ω > Ω > Ω
1.63
[37]
AC C
SAL
6.65
EP
GN
M AN U
Trend
TE D
Glass Code
SC
Comparison of JO parameters (× 10( cm2) of the present glass system with others (NZLE0: 74.5NaH2PO420ZnO-5Li2CO3-0.5Er2O3; TZL: 70TeO2-25ZnO-5La2O3-0.01Er2O3; GN: 75GeO2-25Na2O-0.01Er2O3; PBA: 65SiO2-25Al2O3-10La2O3-0.01Er2O3; SAL: 55P2O5-40BaO-5Al2O3-0.01Er2O3).
Phosphate
4.05
0.97
0.94
Ω > Ω > Ω
1.03
[38]
TeO2-ZnO-Li2O
6.56
1.6
1.44
Ω > Ω > Ω
1.11
[40]
Borotellurite
4.871
2.621
2.483
Ω > Ω > Ω
1.05
[39]
Telluro-fluoroborate
1.774
0.277
0.699
Ω > Ω > Ω
0.400
[30]
Lithium tetraborate
12.07
2.40
3.87
Ω > Ω > Ω
0.62
[41]
Phosphate
11.37
2.68
2.45
Ω > Ω > Ω
1.09
[42]
ACCEPTED MANUSCRIPT
Fig. 3 illustrates the Er3+ ion concentration dependent variation of the spectroscopic quality factor as well as Ω , Ω , and Ω . The spectroscopic quality factor ( = Ω ⁄Ω ) is used to describe the strength of stimulated emission strengths of Er3+ ions in the host glass matrix. In this work, the decreasing trend of quality factor with increasing Er3+ ion concentration up to 1.5 mol% is observed. The Ω parameter
RI PT
revealed the highest sensitiveness to the environment as compared to Ω and Ω . Furthermore, the Ω and
Ω parameters displayed a monotonic variation as a function of Er3+ ion contents, indicating a low sensitivity to the environmental change of Er3+ ion. Amongst all synthesized glasses, PZSMEr0.5 sample
SC
Ω2 Ω4
3
Ω6 Ω4/Ω6
8 6 4 2
M AN U
10
0 0.0
0.5
1.0
1.5
2.0
2
1
Quality Factor
12
TE D
Intensity Parameters (×10-20 cm2)
exhibited highest value of Ω , implying its strongest Er-O covalency and highest asymmetry.
0 2.5
Er2O3 Concentration (mol%)
Luminescence properties
AC C
4.4
EP
Fig. 3. Er2O3 ions concentration dependent variation of JO intensity parameters and quality factor
Fig. 4 displays the room temperature luminescence spectra of all glass samples under 476 nm
excitations. Un-doped sample did not reveal any significant emission peak as expected. However, Er3+ ions doped glass samples exhibited two prominent peaks centered at about 654 nm (red) and 541 nm (green), which are assigned to the transition from the excited states (4F9/2 and 4S3/2) to the ground state (4I15/2) of Er3+ ion, respectively. The peak positions and their assignments are listed in Table 4. Furthermore, the PL intensity displayed slight enhancement with increasing concentration of Er3+ up to 1.0 mol% and quenched beyond this concentration.
ACCEPTED MANUSCRIPT
800 PZSMEr1.0
RI PT
PZSMEr1.5
400 PZSMEr0.5 PZSMEr0.0 PZSMEr2.0
200
0 600
700
SC
Intensity (a.u.)
600
800
M AN U
Wavelength (nm)
Fig. 4. Luminescence spectra of the Er3+ doped magnesium zinc sulfophosphate glasses Table 4
Er3+ ions contents dependent emission peak positions (nm) and their assignments
S3/2→4I15/2
4
F9/2→4I15/2
PZSM Er1.0
PZSM Er1.5
PZSM Er2.0
541.0
542.0
541.0
541.0
653.5
654.5
654.0
653.5
EP
4
PZSM Er0.5
TE D
Transition
Fig. 5 displays the variation in the PL peak intensity for all transitions as a function of Er3+ ion concentration. It is evident that the peak intensity of 4S3/2→4I15/2 transition revealed the highest value
AC C
irrespective of Er2O3 doping concentration. Besides, the emission intensities are quenched for Er2O3 doping contents more than 1.0 mol%.
ACCEPTED MANUSCRIPT
600
4 S3/2
4 I15/2
4 F9/2
4 I15/2
RI PT
Peak Intensity (a.u.)
800
200
0 0.0
0.5
1.0
SC
400
1.5
2.0
M AN U
Er2O3 Concentration (mol%)
Fig. 5. Er2O3 concentration dependent variation of PL peak intensity for prepared glass systems.
Partial energy level diagram of the Er3+ ions (Fig. 6) is used to describe the emission mechanism. Excitation at 476 nm promotes the Er3+ ion from 4I15/2 to 4F7/2 level where the multi-phonon non-radiative
TE D
decays allow populating both (2H11/2 + 4S3/2) and 4F9/2 excited states, thereby produce green and red emission. The reduction in the green emission intensity with increasing the erbium content can be correlated to cross-relaxation (CR) process between two neighboring RE ions. Generally, the CR mechanism is more probable at higher concentration of the RE ions when the ion-ion distances are short enough. Conversely, the CR decays such as (4S3/2, 4I15/2)-(4I9/2, 4I13/2) and (4F9/2, 4I15/2)-(4I11/2, 4I13/2) are
AC C
EP
responsible for the quenching of green luminescence band.
M AN U
SC
RI PT
ACCEPTED MANUSCRIPT
Fig. 6. Partial energy level diagram of Er3+ ion.
Table 5 enlists the values of calculated magnetic W3 and electric W3 transition probability, radiative lifetime (_` ) and branching ratios (d` ) corresponding to the transition from the upper manifold states, 4I13/2, 4I11/2, 4I9/2, 4F9/2, 4S3/2, 2H11/2, and 4F7/2 to their corresponding lower-lying manifold states.
TE D
Table 6 summarizes the calculated values of the radiative properties of the present glass system including the transition probability (W), radiative lifetime _` ), peak stimulated emission cross-section ik and
branching ratio d` . Irrespective of Er2O3 ion concentration, the transition of 4S3/2→4I15/2 for each glass
revealed highest emission cross-section. The values of ik for 4S3/2→4I15/2 transition are found to be
AC C
glasses, respectively.
EP
81.5311, 85.8211, 81.3811 and 63.0042 for PZSMEr0.5, PZSMEr1.0, and PZSMEr1.5 and PZSMEr2.0
ACCEPTED MANUSCRIPT
Table 5 Values of the energy difference ∆ , W3 (s-1) and W3 (s-1), d (%) and _` (ms) for the prepared glass system. Transition
Wavenumber
(s )
(s )
-1
-1
y (%)
(ms)
RI PT
(cm-1) PZSMEr0.5 I13/2→4I15/2
6,510
0.0195
0.1173
1.4316
209.3994
50.5151
100.00
4
I11/2→4I13/2
3,732
0.0331
0.1708
1.0864
44.11305
11.2853
15.2028
I15/2
10,245
0.0282
0.0003
0.3953
308.9972
0.0000
84.7972
I9/2→4I11/2
2,255
0.003
0.0674
0.1271
2.1850
4
I13/2
5,990
0.0004
0.0106
0.7162
88.8099
4
I15/2
12,500
0.0000
0.1732
0.0099
548.0090
F9/2→4I9/2
2,790
0.1279
0.0059
0.0281
4
I11/2
5,045
0.0704
0.0112
4
I13/2
8,780
0.0101
0.1533
4
I15/2
15,290
0.0000
0.5354
S3/2→4I9/2
5,850
0.0000
0.0788
4
I11/2
8,105
0.0000
0.0042
4
I13/2
11,840
0.0000
4
I15/2
18,350
H11/2→4F9/2
3,867
4
I9/2
6,657
4
I11/2
8,912
4
I13/2
4
I15/2
2
0.0000
13.8632
0.0000
85.5441
13.0060
3.4931
0.3810
1.2839
133.6832
7.9266
3.2705
0.0714
222.1250
0.0000
5.1299
0.4619
3949.737
0.0000
91.2186
0.2542
132.7452
0.0000
4.6270
0.0739
63.0744
0.0000
2.1985
0.0000
0.3462
791.4615
0.0000
27.5871
0.0000
0.0000
0.2211
1881.6748
0.0000
65.5874
0.3629
0.0224
0.0022
80.2568
0.2687
0.3344
0.2077
0.0662
0.2858
293.7240
0.0000
1.2198
0.0357
0.1382
0.0371
236.0536
127.3626
1.5092
M AN U
4
0.5927
TE D
4
1.6122
EP
4
AC C
4
SC
4
12,647
0.0230
0.0611
0.0527
386.5573
85.1771
1.9591
19,157
0.7125
0.4123
0.0925
22869.9290
0.0000
94.9774
F7/2→4F9/2
5,201
0.0121
0.0342
0.0151
20.5670
0.0000
0.2269
4
I9/2
7,991
0.0163
0.0954
0.4277
293.6211
0.0000
3.2397
4
I11/2
10,246
0.0035
0.2648
0.1515
698.9013
0.0000
7.7114
4
I13/2
13,981
0.0000
0.3371
0.0001
1829.4152
0.0000
20.1852
4
I15/2
20,491
0.0000
0.1468
0.6266
6220.6619
0.0000
68.6367
4
3.8474
2.7443
1.5610
0.2309
0.3486
0.0415
0.1103
ACCEPTED MANUSCRIPT
PZSMEr1.0 I13/2→4I15/2
6,510
0.0195
0.1173
1.4316
216.2515
48.5957
100.00
4
I11/2→4I13/2
3,736
0.0331
0.1708
1.0864
44.1342
10.8565
15.4135
I15/2
10,246
0.0282
0.0003
0.3953
301.7797
0.0000
84.5865
I9/2→4I11/2
2,254
0.003
0.0674
0.1271
2.1127
1.5509
0.6090
4
I13/2
5,990
0.0004
0.0106
0.7162
95.9401
0.0000
15.9475
4
I15/2
12,500
0.0000
0.1732
0.0099
501.9963
0.0000
83.4435
F9/2→4I9/2
2,790
0.1279
0.0059
0.0281
10.3143
3.3603
0.3317
4
I11/2
5,044
0.0704
0.0112
1.2839
132.6725
4
I13/2
8,780
0.0101
0.1533
0.0714
203.4317
4
I15/2
15,290
0.0000
0.5354
0.4619
3764.8422
S3/2→4I9/2
5,850
0.0000
0.0788
0.2542
4
I11/2
8,104
0.0000
0.0042
4
I13/2
11,840
0.0000
4
I15/2
18,350
H11/2→4F9/2
4
4
4
SC
4
3.4034
0.0000
4.9350
0.0000
91.3299
133.4944
0.0000
4.2909
0.0739
67.0856
0.0000
2.1564
0.0000
0.3462
861.7387
0.0000
27.6991
0.0000
0.0000
0.2211
2048.7565
0.0000
65.8536
3,867
0.3629
0.0224
0.0022
63.0899
0.2585
0.3240
I9/2
6,657
0.2077
0.0662
0.2858
245.1996
0.0000
1.2539
4
I11/2
8,911
0.0357
0.1382
0.0371
205.2417
122.5231
1.6761
4
I13/2
12,647
0.0230
0.0611
0.0527
338.8662
81.9406
2.1519
4
I15/2
19,157
0.7125
0.4123
0.0925
18497.8785
0.0000
94.5941
F7/2→4F9/2
5,201
4
I9/2
7,991
4
I11/2
4
I13/2
4
I15/2
TE D
EP
4
0.0121
0.0342
0.0151
17.7907
0.0000
0.1329
0.0163
0.0954
0.4277
288.3997
0.0000
2.1542
AC C
2
M AN U
7.6254
4
2.8029
1.6622
0.2426
0.3214
0.0511
10,245
0.0035
0.2648
0.1515
654.6710
0.0000
4.8901
13,981
0.0000
0.3371
0.0001
1669.5788
0.0000
12.4711
20,491
0.0000
0.1468
0.6266
10757.1763
0.0000
80.3517
0.0747
3.9708
PZSMEr1.5
4
I13/2→4I15/2
6,510
0.0195
0.1173
1.4316
203.3299
48.5059
100.00
4
I11/2→4I13/2
3,736
0.0331
0.1708
1.0864
40.2231
10.8364
15.6436
I15/2
10,246
0.0282
0.0003
0.3953
275.3319
0.0000
84.3564
4
3.7758
RI PT
4
3.0638
ACCEPTED MANUSCRIPT
2,254
0.003
0.0674
0.1271
1.9892
1.5481
0.4770
4
I13/2
5,990
0.0004
0.0106
0.7162
289.5559
0.0000
39.0419
4
I15/2
12,500
0.0000
0.1732
0.0099
448.5617
0.0000
60.4812
F9/2→4I9/2
2,790
0.1279
0.0059
0.0281
8.5106
3.3541
0.3164
4
I11/2
5,044
0.0704
0.0112
1.2839
124.2279
7.6113
3.5153
4
I13/2
8,780
0.0101
0.1533
0.0714
181.6589
0.0000
4.8437
4
I15/2
15,290
0.0000
0.5354
0.4619
3425.0752
0.0000
91.3247
S3/2→4I9/2
5,850
0.0000
0.0788
0.2542
124.2277
0.0000
4.1671
4
I11/2
8,104
0.0000
0.0042
0.0739
64.3187
4
I13/2
11,840
0.0000
0.0000
0.3462
826.8311
4
I15/2
18,350
0.0000
0.0000
0.2211
1965.7649
H11/2→4F9/2
3,867
0.3629
0.0224
0.0022
4
I9/2
6,657
0.2077
0.0662
4
I11/2
8,911
0.0357
0.1382
4
I13/2
12,647
0.0230
0.0611
4
I15/2
19,157
0.7125
0.4123
F7/2→4F9/2
5,201
0.0121
0.0342
4
I9/2
7,991
0.0163
4
I11/2
10,245
4
I13/2
13,981
4
I15/2
20,491
4
SC 0.0000
27.7354
0.0000
65.9400
48.8666
0.2580
0.3034
0.2858
201.5563
0.0000
1.2449
0.0371
175.3799
122.2968
1.8385
0.0527
290.7253
81.7892
2.3008
0.0925
15270.1085
0.0000
94.3124
0.0151
15.4295
0.0000
0.1242
0.0954
0.4277
265.6231
0.0000
2.1387
0.0035
0.2648
0.1515
594.6409
0.0000
4.7877
0.0000
0.3371
0.0001
1489.2722
0.0000
11.9908
0.6266
10055.1282
0.0000
80.9586
0.0805
5.0197
M AN U
2.1575
TE D
2
0.0000
0.1468
I13/2→4I15/2
6,510
0.0195
0.1173
1.4316
150.4551
48.7592
100.00
4
I11/2→4I13/2
3,714
0.0331
0.1708
1.0864
29.8022
10.8930
16.6086
I15/2
10,224
0.0282
0.0003
0.3953
204.3296
0.0000
83.3914
I9/2→4I11/2
2,276
0.003
0.0674
0.1271
1.4801
1.5561
0.7488
4
I13/2
5,990
0.0004
0.0106
0.7162
67.7463
0.0000
16.7088
4
I15/2
12,500
0.0000
0.1732
0.0099
334.6695
0.0000
82.5423
F9/2→4I9/2
2,790
0.1279
0.0059
0.0281
6.4195
3.3716
0.3505
4
4
0.3354
0.0618
PZSMEr2.0
4
4
0.2666
0.0000
EP
4
AC C
4
1.3483
RI PT
I9/2→4I11/2
4
4.0812
2.4664
ACCEPTED MANUSCRIPT
I11/2
5,066
0.0704
0.0112
1.2839
92.1787
7.5610
3.5741
4
I13/2
8,780
0.0101
0.1533
0.0714
135.5099
0.0000
4.8515
4
I15/2
15,290
0.0000
0.5354
0.4619
2548.0250
0.0000
91.2239
S3/2→4I9/2
5,850
0.0000
0.0788
0.2542
92.0854
0.0000
4.1860
4
I11/2
8,126
0.0000
0.0042
0.0739
47.5310
0.0000
2.1606
4
I13/2
11,840
0.0000
0.0000
0.3462
609.9941
0.0000
27.7289
4
I15/2
18,350
0.0000
0.0000
0.2211
1450.2417
0.0000
65.9245
H11/2→4F9/2
3,793
0.3629
0.0224
0.0022
36.8907
0.2594
0.3035
4
I9/2
6,583
0.2077
0.0662
0.2858
151.3500
4
I11/2
8,859
0.0357
0.1382
0.0371
131.3543
4
I13/2
12,573
0.0230
0.0611
0.0527
217.5171
4
I15/2
19,083
0.7125
0.4123
0.0925
F7/2→4F9/2
5,201
0.0121
0.0342
4
I9/2
7,991
0.0163
0.0954
4
I11/2
10,267
0.0035
0.2648
4
I13/2
13,981
0.0000
0.3371
4
I15/2
20,491
0.0000
0.1468
SC
1.2364
122.9354
2.0773
82.2163
2.4485
11498.9941
0.0000
93.9344
0.0151
11.5565
0.0000
0.1254
0.4277
197.1583
0.0000
2.1386
0.1515
443.0258
0.0000
4.8055
0.0001
1111.4549
0.0000
12.0560
7455.8869
0.0000
80.8745
M AN U
0.0000
TE D
4
EP
2
AC C
4
0.6266
0.3580
RI PT
4
0.4546
0.0817
0.1085
ACCEPTED MANUSCRIPT
Table 6 Values of n (nm), ∆nMM (nm), W (s-1), ik (×10-22 cm2) as well as experimental and calculated d` (%) for the prepared glass system. ∆ (nm)
(s ) -1
PZSMEr0.5
4
S3/2→4I15/2
541.5
8.0525
1881.6748
81.5311
4
F9/2→4I15/2
652.5
46.4614
3949.7374
62.5340
4
S3/2→4I15/2
541.5
8.5472
2048.7565
85.8211
4
F9/2→4I15/2
654
42.9001
3764.8422
66.8549
4
S3/2→4I15/2
541
8.6271
1965.7649
4
F9/2→4I15/2
653.5
42.7369
4
S3/2→4I15/2
5420
8.2533
4
F9/2→4I15/2
654.5
42.5183
PZSMEr2.0
65.5874
70.5632
91.2186
30.5246
65.8536
69.4754
91.3299
81.3811
31.0530
65.9400
3425.0751
60.9422
68.9470
91.3247
1450.2417
63.0042
29.7515
65.9245
2548.0249
45.6907
70.2485
91.2239
SC
PZSMEr1.5
y (%) (Cal.)
29.4368
M AN U
PZSMEr1.0
y (%) (Exp.)
z| (×10-22 cm2)
Transition
RI PT
| (nm)
Glass
Among all the samples, PZSMEr1.0 glass displayed the highest emission cross-section for S3/2→4I15/2 transition. The value of ik for PZSMEr1.0 glass (Table 7) is discerned to be comparatively
4
higher than the reported STB0.5E [44], KTFPEr [45], SALSFEr10 [46], TZLF1.0Er [47], LBTAFEr10
TE D
[48] and Soda lime silicate [49] glasses. It can be concluded the 1.0 mol% Er3+ doped magnesium zinc
AC C
EP
sulfophosphate glass is a potential candidate for the fabrication of green laser.
ACCEPTED MANUSCRIPT
Table 7 Values of n (nm), ∆nMM (nm), W (s-1), ik (×10-22 cm2), calculated and experimental d` (%) for the 4S3/2 level under 476 nm excitation of the prepared glass system (STB0.5E: 39.5H3BO3-15TeO2-15SrCO3-10SrF2-10BaCO3-10BaF20.5Er2O3; KTFPEr: 50(NaPO3)6-10TeO2-20AlF3-19RF-1Er2O3; SALSFEr10: 42SiO2-10Al2O3-24LiF-23SrF2-1Er2O; TZLF1.0Er: 59TeO2-20ZnO-20LiF-1Er2O3; LBTAFEr10: 49PbO-30H3BO3-10TiO2-10AlF3-1Er2O3). Transition
| (nm)
∆ (nm)
(s-1)
S3/2→4I15/2
541.5
STB0.5E [44]
4
S3/2→4I15/2
550
9
KTFPEr [45]
4
S3/2→4I15/2
550
16
SALSFEr10 [46]
4
S3/2→4I15/2
545
18.16
2350.30
TZLF1.0Er [47]
4
S3/2→4I15/2
550
16.7
1510
LBTAFEr10 [48]
4
S3/2→4I15/2
547
17.91
Soda lime silicate [49]
4
S3/2→4I15/2
576
22.5
2048.7565
85.8211
30.5246
65.8536
1468
68.5
73
68
1309
40.88
-
67
60.1
-
67.3
27.1
-
66
1279
34.7
-
67
1113
25.5
-
68.5
M AN U
Conclusion
8.5472
TE D
5.
[Present
y (%) (Cal.)
SC
4
PZSMEr1.0 work]
y (%) (Exp.)
z| (×10-22cm2)
RI PT
Glass
A series magnesium zinc sulfophosphate glass with varying concentration of Er2O3 doping were synthesized using conventional melt quenching technique. The spectral properties of Er3+ ions inside the host glass matrix were thoroughly analyzed to determine the feasibility of fabricating photonic devices. The absorption spectra exhibited several prominent peaks and the absorbance strongly depended on the
EP
Er3+ ion contents. The JO theory is used to calculate various radiative parameters which displayed significant improvement with the increasing Er3+ ion contents. The higher oscillator strengths
AC C
authenticated the occurrence of lower site symmetry around the Er3+ ion in the prepared glass system. Furthermore, the appearance of higher oscillator strengths of the hypersensitive transition manifested the lower site symmetry around the Er3+ ion in the glass system. The PL peaks intensities are steadily increased up to 1.0 mol% of Er3+ and decreased thereafter. Among all glasses, PZSMEr1.0 revealed the maximum stimulated emission cross-section for 4F9/2→4I15/2 transition. The magnitudes of the JO intensity parameters following the trend of Ω2 >Ω4 >Ω6 demonstrated a significant increase in the spectroscopic
quality factors. The value of branching ratio as much as 60% is accomplished for 4F9/2→4I15/2 and 4S3/2→ 4
I15/2 transitions. The highest value of _` is observed to be 5.0197 ms for the glass with 2.0 mol% of
Er2O3. The improvement of the spectroscopic features of Er3+ ion through their controlled doping inside
ACCEPTED MANUSCRIPT
the magnesium zinc sulfophosphate glass host is demonstrated. The excellent features of the results suggest that these glass compositions are prospective for diverse photonic applications.
Acknowledgements through Vote 12H42, 13H50 (GUP/RU) and 4F424 (FRGS).
References
P.R. Rao, G.M. Krishna, M. Brik, Y. Gandhi, and N. Veeraiah, Fluorescence features of Sm3+
SC
[1]
RI PT
The authors wish to thank to UTM and Ministry of Higher Education for the financial support
ions in Na2SO4–MO–P2O5 glass system—Influence of modifier oxide, J. Lumin. 131(2) (2011) 212-217.
M. Jayasimhadri, L. Moorthy, S. Saleem, and R. Ravikumar, Spectroscopic characteristics of
M AN U
[2]
Sm3+-doped alkali fluorophosphate glasses, Spectrochim. Acta Mol. Biomol. Spectrosc. 64(4) (2006) 939-944. [3]
I. Hager, R. El-Mallawany, and A. Bulou, Luminescence spectra and optical properties of TeO2– WO3–Li2O glasses doped with Nd, Sm and Er rare earth ions, Physica B: Condensed Matter 406(4) (2011) 972-980.
[4]
A. Agarwal, I. Pal, S. Sanghi, and M. Aggarwal, Judd–Ofelt parameters and radiative properties
[5]
TE D
of Sm3+ ions doped zinc bismuth borate glasses, Opt. Mater. 32(2) (2009) 339-344. Z. Mazurak, S. Bodył, R. Lisiecki, J. Gabryś-Pisarska, and M. Czaja, Optical properties of Pr3+, Sm3+ and Er3+ doped P2O5–CaO–SrO–BaO phosphate glass, Opt. Mater. 32(4) (2010) 547-553. [6]
S. Schweizer, L.W. Hobbs, M. Secu, J.-M. Spaeth, A. Edgar, and G.V. Williams, Photostimulated
449-451.
T. Suratwala, R. Steele, G. Wilke, J. Campbell, and K. Takeuchi, Effects of OH content, water
AC C
[7]
EP
luminescence in Eu-doped fluorochlorozirconate glass ceramics, Appl. Phys. Lett. 83(3) (2003)
vapor pressure, and temperature on sub-critical crack growth in phosphate glass, J. Non-Cryst. Solids 263 (2000) 213-227.
[8]
R. Praveena, V. Venkatramu, P. Babu, and C. Jayasankar, Fluorescence spectroscopy of Sm3+
ions in P2O5–PbO–Nb2O5 glasses, Physica B: Condensed Matter 403(19) (2008) 3527-3534.
[9]
K. Wei, D. Machewirth, J. Wenzel, E. Snitzer, and G. Sigel, Pr3+-doped Ge-Ga-S glasses for 1.3 µm optical fiber amplifiers, J. Non-Cryst. Solids 182(3) (1995) 257-261.
[10]
S. Tanabe, N. Sugimoto, S. Ito, and T. Hanada, Broad-band 1.5 µm emission of Er3+ ions in bismuth-based oxide glasses for potential WDM amplifier, J. Lumin. 87 (2000) 670-672.
ACCEPTED MANUSCRIPT
[11]
H. Chen, M. Leblanc, and G. Schinn, Gain enhanced L-band optical fiber amplifiers and tunable fiber lasers with erbium-doped fibers, Opt. Commun. 216(1) (2003) 119-125.
[12]
K. Thyagarajan and J. Kaur, A novel design of an intrinsically gain flattened erbium doped fiber, Opt. Commun. 183(5) (2000) 407-413. K. Oh, A. Kilian, and T. Morse, Analysis of spectroscopic properties of erbium doped Ta2O5–
RI PT
[13]
Al2O3–SiO2 optical fiber, J. Non-Cryst. Solids 259(1) (1999) 10-15. [14]
H. Inoue, K. Soga, and A. Makishima, Simulation of the optical properties of Er: ZBLAN glass, J. Non-Cryst. Solids 298(2) (2002) 270-286.
[15]
J. Pardo, J. Peña, R. Merino, R. Cases, A. Larrea, and V. Orera, Spectroscopic properties of Er3+
SC
and Nd3+ doped glasses with the 0.8CaSiO3–0.2Ca3(PO4)2 eutectic composition, J. Non-Cryst. Solids 298(1) (2002) 23-31.
S. Jiang, M. Myers, and N. Peyghambarian, Er3+ doped phosphate glasses and lasers, J. Non-
M AN U
[16]
Cryst. Solids 239(1) (1998) 143-148. [17]
Z. Yao, Y. Ding, T. Nanba, and Y. Miura, Compositional dependences of Judd–Ofelt parameters of Er3+ in borosilicate glasses, Phys. Chem. Glasses 40(4) (1999) 179-183.
[18]
E. Chicklis, C. Naiman, R. Folweiler, D. Gabbe, H. Jenssen, and A. Linz, High‐Efficiency Room‐Temperature 2.06‐µm Laser Using Sensitized Ho3+: YLF, Appl. Phys. Lett. 19(4) (1971) 119-121.
V. Dimitrov and S. Sakka, Electronic oxide polarizability and optical basicity of simple oxides. I,
TE D
[19]
J. Appl. Phys. 79(3) (1996) 1736-1740. [20]
V. Rodriguez, I. Martin, R. Alcala, and R. Cases, Optical properties and cross relaxation among Sm3+ ions in fluorzincate glasses, J. Lumin. 54(4) (1992) 231-236. C. Görller-Walrand and K. Binnemans, Spectral intensities of ff transitions, Handbook on the
EP
[21]
physics and chemistry of rare earths 25 (1998) 101-264. [22]
D. Ramteke, A. Balakrishna, V. Kumar, and H. Swart, Luminescence dynamics and investigation
[23]
AC C
of Judd-Ofelt intensity parameters of Sm3+ ion containing glasses, Opt. Mater. 64 (2017) 171-178.
Y. Ratnakaram, S. Babu, L.K. Bharat, and C. Nayak, Fluorescence characteristics of Nd3+ doped
multicomponent fluoro-phosphate glasses for potential solid-state laser applications, J. Lumin. 175 (2016) 57-66.
[24]
M. Weber, D. Ziegler, and C.A. Angell, Tailoring stimulated emission cross sections of Nd3+
laser glass: Observation of large cross sections for BiCl3 glasses, J. Appl. Phys. 53(6) (1982) 4344-4350. [25]
K. Pradeesh, C. Oton, V. Agotiya, M. Raghavendra, and G.V. Prakash, Optical properties of Er3+ doped alkali chlorophosphate glasses for optical amplifiers, Opt. Mater. 31(2) (2008) 155-160.
ACCEPTED MANUSCRIPT
[26]
C.K. Jørgensen and B. Judd, Hypersensitive pseudoquadrupole transitions in lanthanides, Mol. Phys. 8(3) (1964) 281-290.
[27]
V. Sreedhar, N. Vijaya, D. Ramachari, and C. Jayasankar, Luminescence studies on Er3+-doped zincfluorophosphate glasses for 1.53 µm laser applications, J. Mol. Struct. 1130 (2017) 1001-
[28]
RI PT
1008. T. Srihari and C. Jayasankar, Spectral investigations of Sm3+-doped niobium phosphate glasses, Opt. Mater. 66 (2017) 35-42. [29]
W. Carnall, P. Fields, and K. Rajnak, Electronic energy levels in the trivalent lanthanide aquo ions. I. Pr3+, Nd3+, Pm3+, Sm3+, Dy3+, Ho3+, Er3+, and Tm3+, J. Chem. Phys. 49(10) (1968) 4424-
[30]
SC
4442.
P. Karthikeyan, P. Suthanthirakumar, R. Vijayakumar, and K. Marimuthu, Structural and
M AN U
luminescence behaviour of Er3+ doped telluro-fluoroborate glasses, J. Mol. Struct. 1083 (2015) 268-277. [31]
E. Davis and N. Mott, Conduction in non-crystalline systems V. Conductivity, optical absorption and photoconductivity in amorphous semiconductors, Philosophical Magazine 22(179) (1970) 0903-0922.
[32]
S. Tanabe, T. Ohyagi, N. Soga, and T. Hanada, Compositional dependence of Judd-Ofelt parameters of Er3+ ions in alkali-metal borate glasses, Phys. Rev. B 46(6) (1992) 3305. W.F. Krupke, Optical Absorption and Fluorescence Intensities in Several Rare-Earth-Doped Y2O3
TE D
[33]
and LaF3 Single Crystals, Phys. Rev. 145(1) (1966) 325. [34]
G. Lakshminarayana, R. Yang, M. Mao, and J. Qiu, Spectral analysis of RE3+(RE= Sm, Dy, and Tm): P2O5–Al2O3–Na2O glasses, Opt. Mater. 31(10) (2009) 1506-1512. X. Zou and T. Izumitani, Spectroscopic properties and mechanisms of excited state absorption
EP
[35]
and energy transfer upconversion for Er3+-doped glasses, J. Non-Cryst. Solids 162(1) (1993) 6880.
A. Langar, C. Bouzidi, H. Elhouichet, and M. Férid, Er–Yb codoped phosphate glasses with
AC C
[36]
improved gain characteristics for an efficient 1.55 µm broadband optical amplifiers, J. Lumin. 148 (2014) 249-255.
[37]
J. Yang, S. Dai, N. Dai, L. Wen, L. Hu, and Z. Jiang, Investigation on nonradiative decay of
4
[38]
I13/2→ 4I15/2 transition of Er3+-doped oxide glasses, J. Lumin. 106(1) (2004) 9-14.
H. Desirena, E. De la Rosa, L. Diaz-Torres, and G. Kumar, Concentration effect of Er3+ ion on the spectroscopic properties of Er3+ and Yb3+/Er3+ co-doped phosphate glasses, Opt. Mater. 28(5) (2006) 560-568.
ACCEPTED MANUSCRIPT
[39]
M. Azlan, M. Halimah, and H. Sidek, Linear and nonlinear optical properties of erbium doped zinc borotellurite glass system, J. Lumin. 181 (2017) 400-406.
[40]
H. Desirena, E. De la Rosa, A. Shulzgen, S. Shabet, and N. Peyghambarian, Er3+ and Yb3+ concentration effect in the spectroscopic properties and energy transfer in Yb3+/Er3+ codoped
[41]
RI PT
tellurite glasses, J. Phys. D: Appl. Phys. 41(9) (2008) 095102. B. Padlyak, R. Lisiecki, and W. Ryba-Romanowski, Spectroscopy of the Er-doped lithium tetraborate glasses, Opt. Mater. 54 (2016) 126-133. [42]
S.N. Rasool, B. Jamalaiah, K. Suresh, L.R. Moorthy, and C. Jayasankar, Spectroscopic properties of Er3+-doped phosphate based glasses for broadband 1.54 µm emission, J. Mol. Struct. 1130
[43]
SC
(2017) 837-843.
C. Bouzidi, H. Elhouichet, and A. Moadhen, Yb3+ effect on the spectroscopic properties of Er–Yb codoped SnO2 thin films, J. Lumin. 131(12) (2011) 2630-2635.
K. Annapoorani, N.S. Murthy, T. Ravindran, and K. Marimuthu, Influence of Er3+ ion
M AN U
[44]
concentration on spectroscopic properties and luminescence behavior in Er3+ doped strontium telluroborate glasses, J. Lumin. 171 (2016) 19-26. [45]
M. Jayasimhadri, L. Moorthy, K. Kojima, K. Yamamoto, N. Wada, and N. Wada, Er3+-doped tellurofluorophosphate glasses for lasers and optical amplifiers, J. Phys.: Condens. Matter 17(48) (2005) 7705.
C. Kesavulu, V. Sreedhar, C. Jayasankar, K. Jang, D.-S. Shin, and S.S. Yi, Structural, thermal and
TE D
[46]
spectroscopic properties of highly Er3+-doped novel oxyfluoride glasses for photonic application, Mater. Res. Bull. 51 (2014) 336-344. [47]
P. Babu, H.J. Seo, C. Kesavulu, K.H. Jang, and C. Jayasankar, Thermal and optical properties of
[48]
EP
Er3+-doped oxyfluorotellurite glasses, J. Lumin. 129(5) (2009) 444-448. B. Jamalaiah, T. Suhasini, L.R. Moorthy, K.J. Reddy, I.-G. Kim, D.-S. Yoo, and K. Jang, Visible and near infrared luminescence properties of Er3+-doped LBTAF glasses for optical amplifiers,
[49]
AC C
Opt. Mater. 34(5) (2012) 861-867. Y. Sharma, S. Surana, R. Singh, and R. Dubedi, Spectral studies of erbium doped soda lime
silicate glasses in visible and near infrared regions, Opt. Mater. 29(6) (2007) 598-604.
ACCEPTED MANUSCRIPT
Highlights
Erbium (Er3+) ions doped magnesium zinc sulfophosphate glass system prepared by melt-quenching method.
PZSMEr0.5 glass sample showed the largest value of Ωଶ which denotes to the stronger asymmetry of the
RI PT
site occupied by Er3+ ion. There was slight PL intensity enhancement with increasing concentration of Er3+ up to 1.0 mol%.
PZSMEr1.0 glass showed the highest emission cross-section for 4S3/2→4I15/2 transition.
AC C
EP
TE D
M AN U
SC