Energy transfer in Sm3+:Eu3+ system in zinc sodium phosphate glasses

doi:10.1016/S0925-3467(03)00183-6

Optical Materials

Volume 24, Issue 4, January 2004, Pages 671-677

https://doi.org/10.1016/S0925-3467(03)00183-6 Get rights and content

Abstract

The mechanism of nonradiative energy transfer process in zinc sodium phosphate glass system co-doped with samarium and europium ion has been examined under cw laser excitation. Donor–acceptor distance and quantum efficiency of transfer have been evaluated using the relevant theoretical expressions. Transfer probabilities have been determined using the overlap integral and relative fluorescence methods. The Forster–Dexter theoretical predictions are found to be in excellent agreement with experimental results. The nonresonant energy transfer assisted by phonons is the dominant transfer mechanism in the concentration range taken. Excitation spectra and the decay profile of the samarium ion also support the energy transfer from samarium to europium.

Introduction

Rare earth ions find wide applications in sensitising solid state and glass lasers, infrared quantum counters as well as infrared to visible converters. Energy transfer between ions in solids can be accomplished either radiatively or nonradiatively and the mechanism and kinetics involved have been extensively addressed [1], [2]. Many workers have treated the radiative and nonradiative transitions in the rare earth ions and succeeded in realising energy transfer process in doubly doped crystals and glasses [3], [4], [5], [6]. In particular, the excellent work by Blasse and coworkers has resulted in the elucidation of energy transfer, energy migration and concentration quenching in various rare earth ions [7], [8], [9], [10].

One important consequence of the energy transfer process is the phenomenon of sensitised luminescence in solids. It is an important factor in increasing the laser efficiency of the materials. Hence this phenomenon has a significant application in the research and development of new laser materials and it is possible to remarkably reduce the threshold energy of laser oscillation in these materials. A large number of studies on sensitised luminescence or fluorescence and concentration quenching have been made, since the wide spread interest results from the breadth of research areas encompassed by the phenomena of energy transfer [11], [12]. In this context samarium possesses a relative range of absorption among rare earth ions and hence in particular, it is a good candidate for sensitising Eu³⁺. To enhance the europium emission, many workers have sensitised it by rare earth ions and other ions in different matrices [2], [13]. Reisfeld [14], [15] observed energy transfer from UO²⁺, Bi³⁺ and Sm³⁺ to Eu³⁺ in glasses and found it to be nonradiative with two orders of magnitude enhancement in Eu³⁺ emission. Keeping in view of the above interesting results, in the present work a quantitative evaluation of the nonradiative energy transfer in the Sm³⁺:Eu³⁺ system in zinc sodium phosphate glass has been undertaken.

Section snippets

Experimental

The glasses were prepared using BDH 99.9% purity sodium dihydrogen phosphate and zinc oxide. Samarium and europium oxide of 99.9% purity from Indian Rare Earth Chemicals Ltd. were used as the dopants. Here samarium and europium as dopants in the glasses act as sensitiser and activator respectively. Incorporation of zinc oxide reduces the hygroscopy of the sodium phosphate glasses [16]. Glasses were prepared with the following rare earth combinations.

I.
0.5, 1, 1.5, 2, 2.5 wt.% of samarium.
II.
0.5, 1,

Results and discussion

The fluorescence spectrum of Sm³⁺ and Eu³⁺ in zinc phosphate glass is shown in Fig. 1(a) and (b) respectively. The band assignments for the various emission transitions have been done by invoking the energy level diagram of Eu³⁺ and Sm³⁺ shown in Fig. 2. In the case of samarium the fluorescence measured consists of the emission from the ⁴G_5/2 level to the ground state ⁶H multiplet, and for europium the observed emission consists of transitions from ⁵D₀ to ⁷F multiplet. The emission peaks

Conclusion

The fluorescence spectra of the prepared glass systems exhibit emissions from the ⁴G_5/2 level to the ⁶H multiplet of samarium and ⁵D₀ level to ⁷F multiplet of europium. The excitation spectra revealed the additional bands for Sm³⁺ with high oscillator strengths and the occurrence of energy transfer when co-doped with Eu³⁺ ions. The change of the emission intensities caused by the co-existence of Sm³⁺ and Eu³⁺ and the decay time of Sm³⁺ have been measured. On the basis of the analysis of the

References (30)

B.C. Joshi
J. Non. Cryst. Solids
(1995)
B. Peng et al.
Opt. Mat.
(1995)
M. Eyal et al.
Chem. Phys. Lett.
(1986)
G. Blasse
G. Blasse
Prog. Solid. Stat. Chem.
(1988)
M. Buijs et al.
Chem. Phys. Lett.
(1987)
Y. Yu et al.
J. Alloys Compd.
(1993)
R. Reisfeld et al.
J. Solid State Chem.
(1979)
R. Reisfeld et al.
J. Luminescence
(1976)
P. Nachimuthu et al.
J. Non. Cryst. Solids
(1997)

Z. Pei et al.

J. Sol. State. Chem.

(1994)

J. Qiu et al.

J. Non. Cryst. Solids

(1997)

M. Bettinelli et al.

J. Non. Cryst. Solids

(1996)

R. Reisfeld et al.

J. Solid State Chem.

(1972)

D.C. Yeh et al.

J. Non. Cryst. Solids

(1986)

Cited by (133)

High thermal stability of warm white emitting single phase GdPO<inf>4</inf>: Dy3+/ Sm3+ phosphor for UV excited wLEDs
2024, Journal of Luminescence
Highly thermally stable warm white light emission has been obtained from a single component phosphor; GdPO₄: Dy³⁺/Sm³⁺. A series of GdPO₄: Sm³⁺ (1%)/Dy³⁺ (x%) (x = 0.1, 0.5, 1 and 2) phosphors have been synthesized by the co-precipitation method. The crystal structure and phase purity of the samples obtained were verified by X-ray diffraction. Photoluminescence spectra, luminescence lifetimes are used to study the effect of Dy³⁺ concentration and the energy transfer from Dy³⁺ to Sm³⁺ as a function of excitation wavelength. The nearest-neighbor contributed to the non-radiative energy transfer from Dy³⁺ to Sm³⁺ in GdPO₄, under 273 and 363 nm excitation. A warm white light was obtained from all phosphors excited at 273 nm and for 1 and 2% of Dy³⁺ in GdPO₄:Sm³⁺ under 363 nm excitation. Temperature-dependent luminescence properties are determined for GdPO₄: Sm³⁺ (1%), Dy³⁺ (1%) under 273 nm and 363 nm excitation. The studied phosphor has a good luminescence thermal stability and the determined activation energy for thermal quenching is 1.26 and 0.75 eV for 273 nm and 363 nm excitation wavelengths, respectively. The effect of the Dy³⁺ concentration as an activator ion responsible for the white emission light, at a fixed concentration of Sm³⁺ as a red emission compensator in the Dy³⁺ emission spectrum, was discussed. The low color temperature and high thermal stability indicate that the studied material is a promising solid-state emitting phosphors for the UV chip excited warm wLED applications.
Spectroscopy and absolute photoluminescence quantum yield of Eu3-doped zinc-tellurite glasses for solid state lightning applications
2023, Physica B: Condensed Matter
Spectroscopic properties of Eu³⁺-doped tellurite glass composed of 74 TeO₂ + 15 ZnO +5 Nb₂O₅ + 5 TiO₂ + 1.0 Eu₂O₃(mol %) have been investigated. Phonon energy of the host glass constituents that are linked up with the Eu³⁺ ions have been evaluated from the photoluminescence excitation spectrum which is found to be 760 cm⁻¹. By utilizing the emission spectrum, the Judd-Ofelt (JO) intensity parameters (Ω_λ, λ = 2 and 4) are calculated. The obtained JO parameters are utilized for evaluating the emission cross-sections (σ(λ_p)) of ⁵D₀ → ⁷F_J (J = 1, 2 and 4) transitions. An intense emission at 613 nm due to the transition⁵D₀ → ⁷F₂is observed upon 465 nm excitation. Among these, the ⁵D₀ → ⁷F₂ (613 nm) transition has been exhibited the highest (σ(λ_p)) value and it found to be 2.11 × 10⁻²² cm². For the ⁵D₀ level, quantum efficiency (η) is corroborated theoretically as 58.4% and it is in line with absolute quantum yield of 56.7% obtained by Integrating sphere method. The results of Eu³⁺-doped TZNTEu1.0 glass are significant for the development of solid-state lighting devices at around 613 nm under the excitation of 465 nm.
Distinctive spectroscopic features of samarium ions in the lithium zinc-borate glass
2023, Optical Materials
Inducing the spectral features of samarium ions (Sm³⁺) in a borate glass host with the required enhancements is the main challenge. Hence, transparent glass materials made of Sm-doped lithium zinc borate with high optical quality are created by the melt-quenching approach. XRD reveals the disordered structure and the amorphous character of the obtained glassy materials. The structural modiﬁcations of these glassy materials are observed via FTIR spectroscopy. The incorporation of samarium oxides into the borate glassy system changes the boron coordination from four-to-three. This, in turn, increases non-bridging oxygens (NBO) in the glassy network. The various physical parameters of these glassy materials are evaluated. Moreover, the ligand field characteristics and optical transitions of Sm³⁺-doped lithium zinc-borate glassy materials are scrutinized. The indirect bandgap energy values of these glass materials decrease with Sm₂O₃ additions, whereas the Urbach energies increase gradually. The refractive index values of these glasses lie between 1.20 and 1.42. The tunability of the optical spectra of the investigated glass system, afforded via the various contents of Sm³⁺ ions, allows the absorption edge to be disentangled from the distinguishing optical transitions of Sm³⁺ ions. Prominent spectroscopic features of the results suggest the Sm-doped borate glass system towards future applications.
White luminescence and energy transfer studies in Tb3+-Eu3+ co-doped phosphate glasses
2022, Solid State Sciences
Citation Excerpt :
Due to the general technological importance of glasses, more effort is necessary to have a deeper understanding of the structure-properties connection to find novel materials for varied uses. Glasses are an applicable material in many fields, and are more flexible than crystalline systems in terms of size and form, and they can be doped with a variety of activators while maintaining a high degree of homogeneity [1–3]. The optical properties of a variety of glass matrices, including oxides, fluorides, silicates, and oxyfluorides, have been investigated as a consequence [4–10].
Europium and Terbium co-doped phosphate glasses with a chemical composition of 80NaH₂PO₄–18Na₂CO₃–2Al₂O₃, which have been named PNA, were well produced with melt-quenching technique. We studied the structural and optical properties of the material. According to the XRD pattern, all the samples have an amorphous structure. After adding Tb³⁺, it was revealed that the photoluminescence (PL) intensity of the ⁵D₀ →⁷F₂ transition increased. It was observed that the Tb³⁺ ion functions as a sensitizer for the Eu³⁺ ion, and significantly enhances the spectroscopic features of Eu-doped PNA. We demonstrated the possibility of excitation transfer from Tb³⁺ to Eu³⁺. The radiative lifetime (τ_R) calculated from Judd-Ofelt (J-O) theory, and the, empirically discovered, measured lifetimes (τ_mes) were compared for Eu-doped PNA and (Eu; Tb) co-doped PNA. The results reveal that the quantum efficiency (η) was found to increase after adding Tb³⁺ from 87 to 94% for the ⁵D₀ →⁷F₂ transition. The energy transfer was identified and explained both experimentally using the excitation and emission spectra and theoretically using the J-O theory. The results of the CIE chromaticity coordinates of (Eu, Tb) co-doped PNA were found in the white region, which suggests a significant promise in field emission displays.
RE-codoping effect on emission ability of Sm,Gd- and Sm,Eu-codoped complex borosilicate glasses
2022, Materials Research Bulletin
Sm,Gd- and Sm,Eu-codoped aluminoborosilicate glasses (ABS) with total rare earth (RE) content of 1 or 2 wt.% have been synthesized by melt-quenching technique. Different proportions of RE-codopants were used to examine the codoping effect on the emission ability of pristine and β-irradiated codoped ABS glasses. It was shown that the relative luminescence intensity as well as the reduction efficiency of Sm ions in glass studied reveals non-linear behavior with RE concentration proportion. The same non-linear evolution with RE codoping concentration was observed for Sm³⁺ and Eu³⁺ lifetime in glass studied. The results obtained are consistent with hypothesis on more complicated processes of RE ions participation in the luminescence and/or interaction of different RE redox states and RE sites both between each other and with precursors of glass intrinsic defects.
Fabrications a new family of samarium lead phosphate glasses, determination electrical, structural and optical properties under effect of different gamma doses
2022, Optik
Structural, optical and electrical properties of developed (P₂O₅)₄₇-(Na₂O)₂₃-(Al₂O₃)₆-PbO_(24−x)-(Sm₂O₃)_x (where x = 0.5, 1 and 3 mol%) at different gamma irradiation doses (0, 10, 50 KGy) have been investigated. Melt-quenching method was used for synthesizing these glasses. XRD observations provide for the ampophosity of the as-prepared glasses. The effect of different gamma irradiation doses and Sm₂O₃ contents affect crystallinity of the developed samples. Moreover, the results show a decreasing in the transmittance light as the gamma doses increase from 0 to 50 kGy. The both calculated direct and indirect optical band gap were found to be affected by gamma irradiation doses for (P₂O₅)₄₇-(Na₂O)₂₃-(Al₂O₃)₆-PbO_(24−x)-(Sm₂O₃)_x. On the other hand, the electrical activation energy and electrical conductivity of the glasses were affected by gamma irradiation doses for (P₂O₅)₄₇-(Na₂O)₂₃-(Al₂O₃)₆-PbO_(24−x)-(Sm₂O₃)_x (where x = 0.5, 1 and 3 mol%). These various studies forces to fabricate a glass material that could be utilized to attenuate or reduce gamma-radiation.

View all citing articles on Scopus

View full text

Article preview

Optical Materials

Abstract

Introduction

Section snippets

Experimental

Results and discussion

Conclusion

References (30)

J. Non. Cryst. Solids

Opt. Mat.

Chem. Phys. Lett.

Prog. Solid. Stat. Chem.

Chem. Phys. Lett.

J. Alloys Compd.

J. Solid State Chem.

J. Luminescence

J. Non. Cryst. Solids

J. Sol. State. Chem.

J. Non. Cryst. Solids

J. Non. Cryst. Solids

J. Solid State Chem.

J. Non. Cryst. Solids

Cited by (133)

High thermal stability of warm white emitting single phase GdPO<inf>4</inf>: Dy<sup>3+</sup>/ Sm<sup>3+</sup> phosphor for UV excited wLEDs

Spectroscopy and absolute photoluminescence quantum yield of Eu<sup>3</sup>-doped zinc-tellurite glasses for solid state lightning applications

Distinctive spectroscopic features of samarium ions in the lithium zinc-borate glass

White luminescence and energy transfer studies in Tb<sup>3+</sup>-Eu<sup>3+</sup> co-doped phosphate glasses

RE-codoping effect on emission ability of Sm,Gd- and Sm,Eu-codoped complex borosilicate glasses

Fabrications a new family of samarium lead phosphate glasses, determination electrical, structural and optical properties under effect of different gamma doses