Different Concentrations Of Er3 Research Articles

Preparation of Er3+, Ho3+, Yb3+-doped Bi2WO6 upconversion luminescent materials and their temperature sensing properties

A high-temperature solid-phase method was used to prepare codoped Bi2WO6 upconversion luminescent materials with different concentrations of Er3+, Ho3+, and Yb3+. The microstructure, upconversion luminescence and temperature sensing properties of the synthesized powders were analyzed. X-ray diffraction (XRD) patterns showed that the doping of Er3+, Ho3+, and Yb3+ did not affect the orthorhombic crystal structure of the Bi2WO6 matrix material. As the calcination temperature increased from 800 °C to 1000 °C for 3h, the average particle sizes of the 1% Er3+, 1% Ho3+, 1% Yb3+: Bi2WO6 samples decreased, and the luminescence weakened. Scanning electron microscopy (SEM) images showed that the morphology of the sample for 1% Er3+, 1% Ho3+, 1% Yb3+: Bi2WO6 with calcination at 800 °C was nearly spherical, with particle sizes ranging from 1 to 5 μm and some agglomeration. SEM mapping showed that the elements were more uniformly distributed on the surfaces of the sample particles, and energy-dispersive X-ray spectroscopy (EDS) analysis showed that each element was distributed with in the particles. Er3+, Ho3+, and Yb3+ codoping was used to regulate the Yb3+ doping concentration, and under 980 nm excitation, the strongest upconversion emission was obtained for the prepared 1% Er3+, 1% Ho3+, 1% Yb3+ samples. Compared with that for the Er3+, Yb3+-doped Bi2WO6 sample, the luminescence intensity of the characteristic emission peak of Er3+ at 525 nm for the Er3+, Ho3+, Yb3+-doped sample was weakened, while the luminescence of the characteristic emission peak of Ho3+ was enhanced; these results indicated that energy transfer from Er3+ to Ho3+ occurred. The intensities of the four emission peaks at 525 nm, 546 nm, 660 nm, and 756 nm in the 1% Er3+, 1% Ho3+, 1% Yb3+-doped Bi2WO6 sample increased with increasing excitation pump power from 45 mW to 233 mW. Based on the relationship between the excitation pump power and the emission intensity, all four luminescence peaks originated from two-photon absorption. The fluorescence intensity ratio versus temperature was fitted using three different nonthermally coupled energy level pairs in the range from 298 K to 573 K. The maximum absolute temperature sensitivity of 0.296 K-1 was obtained at 573 K for the Ho3+ nonthermally coupled energy level pair, and the maximum relative temperature sensitivity of 0.279 K-1 was obtained at 298 K. The temperature resolution for characterization using the above nonthermally coupled energy level pairs was calculated, with the temperature resolution δT yielding a minimum value of 0.03 K. The CIE color coordinates at different temperatures were calculated, and the color coordinates gradually moved from the green region to the red region.

Preparation and Ferroelectric Properties of Er Doped BaTiO3 Nanotubes

In this paper, erbium-doped barium titanate nanotubes with different concentrations were prepared by combining the anodic oxidation method with the low-temperature hydrothermal method. The TiO2 nanotubes produced by electrolysis using titanium flakes as substrate were put into barium hydroxide octahydrate solution for hydrothermal reaction, and different concentrations of Er-doped barium titanate nanotubes were prepared by adding different concentrations of Er(NO3)3·5H2O to the reaction solution. The samples with different doping concentrations were analyzed for their morphological structure, physical phase composition and ferroelectric properties. All samples were found to have complete barium titanate nanotube structure, and the diffraction peaks of XRD were compared with the standard Cope, and the doped samples were all tetragonal phase chalcogenide structure with no other impurities generated. From the hysteresis loop diagram of the samples measured by the TF-2000 ferroelectric analyzer, it can be found that the residual polarization intensity of the samples showed a characteristic of increasing and then decreasing with the increase of the doping concentration, and the residual polarization intensity was the largest at 0.151 uC/cm2 under the hydrothermal reaction condition of 180°C and 3 h with the Er3+ concentration of 0.0025 mol/L.

Coherent control of the photonic spin Hall effect by Er3+ ion concentration in an Er3+-doped YAG crystal

We theoretically investigate the effect of doped Er3+ ion concentration on the spin Hall effect (SHE) of light reflected from a Kretschmann-Raether (K-R) structure. In such a structure, an Er3+-doped yttrium aluminum garnet (YAG) crystal acts as the substrate. The excitation of surface plasmon resonance(SPR) leads to the enhancement of the spin splitting of the reflected beam in the resonance reflection dip. Due to the variation of electric dipole moment and energy level lifetime induced by Er3+ ion concentration, the spin-dependent transverse shift is sensitively dependent upon Er3+ ion concentration. Furthermore, under different concentrations of Er3+ ion, the intensity and detuning of the control field have different effects on the magnitude, sign and position of the transverse shift. More importantly, the photonic SHE can be significantly enhanced via choosing the suitable values of the control intensity and detuning at 15% Er3+ ion concentration. Therefore, our scheme may provide a basis for selecting suitable Er3+ ion concentration to enhance the SHE of light in future integrated systems.

Effect of Ca2+ ions on structure and spectroscopic properties of Er3+: KBaY(MoO4)3 crystals

This study successfully grew KBaY(MoO4)3 crystals doped with single Er3+ ions and co-doped with Ca2+/Er3+ ions using the top-seeded solution growth method. Thermal analysis of the KBaY(MoO4)3 crystals was performed by differential scanning calorimetry, and their phase and structure were characterized using X-ray diffraction and Fourier transform infrared spectroscopy. The luminescent properties of the crystals in the visible and near-infrared wavelength ranges under different concentrations of Er3+ ions were analyzed through emission spectroscopy, and the concentration quenching mechanism was investigated in depth. The results showed that the strongest emission intensity was obtained at an Er3+ ion concentration of 5 mol%. Additionally, by substituting Ba2+ ions with Ca2+ ions, the emission intensity was significantly enhanced, especially when the Ca2+ ion doping concentration reached 6 mol%, resulting in the maximum emission intensity. Furthermore, we investigated the effects of matrix structure and lattice distortion on the spectral properties by employing Judd-Ofelt (J-O) theory and studying energy transfer mechanisms. The mechanisms of Ca2+-induced fluorescence quenching and factors influencing the fluorescence decay time were analyzed. Through the analysis of the absorption cross-section, emission cross-section, and gain cross-section of crystals with different Ca2+ ion concentrations, it was found that Ca2+, Er3+: KBYM crystals exhibited a low laser pump threshold. The results demonstrate that the 6 mol% Ca2+, 5 mol% Er3+: KBYM crystals possess excellent performance and are a promising laser gain medium.

Green emission characteristics of Er3+ -doped TeO2-WO3-GeO2 glasses through up and down conversion processes

Different concentrations of Er3+ions doped TeO2-WO3-GeO2 transparent oxyfluoride glassy materials were fabricated by conventional melt quench method and analyzed through X-ray diffraction, Fourier Transform infrared, scanning electron microscope and energy dispersive X-ray, photoluminescence-excitation, visible emission and luminescence decay studies. Various physical, structural, spectroscopic and laser characteristic parameters were evaluated following the Judd-Ofelt theory. The studied glasses were capable of emitting intense green luminescence through (2H11/2,4S3/2) → 4I15/2 transitions. The emission of green luminescence was studied through down-conversion process at 377 nm excitation and up-conversion process at 980 nm excitation. The color coordinates were found to fall in the green region of chromaticity diagram and close to the European Broadcosting Union green illuminant. The evaluated branching ratio, stimulated emission cross-section, gain linewidth, figure of merit and the quantum efficiency corresponding to 4S3/2 → 4I15/2 transition suggests that the studied glasses find wide suitability to design green emitting solid state lighting devices.

Role of Er3+ ion concentration on the Goos–Hänchen shift in an Er3+-doped YAG crystal

We investigate the effect of doped Er3+ ion concentration on the Goos–Hänchen (GH) shift of a reflected beam in a Kretschmann–Raether structure, where an Er3+-doped yttrium aluminum garnet crystal is employed as the substrate. Due to the difference in the electric dipole moment and spontaneous emission decay induced by Er3+ ion concentration, the reflected GH shift is sensitively dependent upon Er3+ ion concentration. Furthermore, it is demonstrated that the intensity and detuning of the control field have different effects on the magnitude, sign, and position of the GH shift under different concentrations of Er3+ ion. Therefore, our scheme may provide a basis for selecting suitable concentrations to realize high-performance optical devices in future integrated systems.

Near-infrared luminescence of Er3+ doped Na0.04K0.96Y(WO4)2 single crystals

Single crystals of the compositions Na0.04K0.96Y(WO4)2 (NKYW) and x mol% Er: Na0.04K0.96Y(WO4)2 (x = 1, 3, 5, 7) (Er: NKYW) have been successfully grown by the top-seeded solution growth (TSSG) method. The growth process parameters have been investigated in detail. X-ray diffraction (XRD) and Raman spectroscopy measurements showed that the K+ and Na+ cations occupied equivalent lattice sites and the crystal structure remained monoclinic. The spectral properties and energy transfer mechanisms of the single crystals doped with different concentrations of Er3+ ions were investigated. According to the Judd-Ofelt theory, the intensity parameters of the 5 mol% Er: NKYW crystal were calculated to be Ω2 = 1.77 × 10−20 cm2, Ω4 = 3.15 × 10−20 cm2, Ω6 = 3.08 × 10−20 cm2, and the radiative transition probability of 4I13/2 → 4I15/2 was 541.25 s−1. The gain cross section of the 5 mol% Er: NKYW crystal at 1542 nm was determined to be 2.63 × 10−20 cm2, indicating that high-quality Er: NKYW single crystals have great potential for laser applications.

Spectroscopic and optical investigations on Er3+ ions doped alkali cadmium phosphate glasses for laser applications

Alkali cadmium phosphate glasses doped with erbium ions were prepared by traditional melt - quenching technique. The FTIR and Raman spectroscopies were performed and employed to investigate the structural changes of the glass network doped with different concentrations of Er3+ ions. The UV–Vis–NIR spectroscopy was used to investigate the optical absorption spectra, optical bandgaps, refractive indices, and related parameters. The Judd – Ofelt (J – O) theory was used to explain the structural changes and to determine the bonds nature in the studied glasses by calculating the intensity parameters Ω2, Ω4, and Ω6. The J – O intensity parameters followed the trend of Ω2 > Ω6 > Ω4 and were used to evaluate some radiative parameters such as electric and magnetic radiative transition probabilities, branching ratios, and radiative lifetimes for the excited levels of the Er3+ ions. The absorption and emission cross-sections for the 4I13/2 → 4I15/2 transition of Er3+ ions were studied, and the gain coefficient was calculated. The higher values of the branching ratios (≥ 0.5) and lifetimes of the present glasses indicate their good suitability for lasers and amplifiers applications.

Frequency upconversion based thermally stable molybdate phosphors in a temperature sensing probe

Er3+–Yb3+ co-doped NaGd(MoO4)2 phosphors with different concentrations of Er3+ and Yb3+ ions have been successfully synthesized via a high-temperature solid-state reaction method.

Judd-Ofelt analysis of spectroscopic measurements of Er3+ doped boro-zincate glasses

• Combined spectral and thermal measurements of high zinc borate glasses doped with different concentrations of Er3+ ions were carried out for investigation this system to be used in optical devises. Glasses based on the base composition (ZnO 70 – B 2 O 3 30 mol %) containing increasing Er 2 O 3 as dopant (0.2 → 2.2 mol%) were synthesized by traditional melting. Collective investigation was done through measuring their UV-visible and structural FTIR spectra. The density and derived physical properties were calculated in relation to the constitution and percent of rare-earth oxide. Optical absorption studies show specific and characteristic peaks which are correlated with the absorption of Er 3+ originated from the ground state 4 I 15/2 to several possible energy transitions. Structural IR data indicate distinct and extended bands from 400-1600 cm −1 which are assigned to the two known characteristic borate units with triangular and tetrahedral coordinations (BO 3 , BO 4 ). The possible forming of ZnO 4 is considered due to the abundance of ZnO (70 mol%) but the intensities of the vibrations of the two borate units are distinctively higher due to the known lightest boron element which is reflected on its oxide (B 2 O 3 ) than other glass forming oxides. The IR spectra have been confirmed by the measurements of the IR spectrum of pure crystalline ZnO to elucidate its specific vibrational sites. The density and molar volume data are correlated with the trivalent erbium ions concentration and their housing in the glass structure. The various optical parameters of the Er 2 O 3 -doped glasses were derived and analyzed in relation to the concentration of Er 3+ ions.

Temperature sensing down to 4 K with erbium-doped tellurite glasses

Two binary tellurite glasses within TeO2–PbCl2–WO3 system with different concentrations of Er3+ ions were prepared by the conventional melt-quench technique and their optical properties were compared with emphasis on their potential use for temperature sensing starting from 4 K. Therefore, absorption and emission spectroscopy was used to determine the emission properties of Er3+ in the visible and near-infrared regions across a wide temperature range of 4-300 K. Photoluminescence emissions resulting from direct absorption or frequency up-conversion were measured across a wide temperature range and their dependence on the concentration of erbium ions and on excitation power density were studied in detail. It was demonstrated that by optimizing concentration of erbium ions, the luminescence intensity ratio of suitably selected thermally coupled/uncoupled levels and their Stark sublevels can be used for the non-contact optical temperature sensing at cryogenic temperatures.

Enhancement of spectroscopic parameters of Er3+-doped cadmium lithium gadolinium silicate glasses as an active medium for lasers and optical amplifiers in the NIR-region

Optical properties and radiative rates of cadmium lithium gadolinium silicate glasses (CLGS) doped with Er3+ are presented. Direct energy gap and its dependence refractive indexes are estimated and presented, as well. We have derived absorption and emission cross-sections and then the estimated possible spectral optical gain for different concentrations of Er3+ at 1 mol%, 1.5 mol%, and 2 mol% are also evaluated. For the three NIR peaks at 800 nm, 1 μm and 1.5 μm, the effect of dopant concentrations on the emission cross section and optical gain factors are investigated. The quenching behaviour occurred in the emission/absorption cross sections as well as optical gain for higher dopant level and at a wavelength of 1 μm is discussed. The present glasses doped with 1.5 mol% and 2 mol% of Er2O3 show higher emission cross sections values at 1.5 μm, the estimated emission cross sections rapidly increased by about of 40% at 1.5 μm of the glass samples doped with 1.5 mol%, and 2 mol% of Er2O3. This increase reflected on the gain factors which show higher values of the same samples at 1.5 μm by ~7−9cm−1

Spectroscopic investigations on 1.53 μm NIR emission of Er3+ doped multicomponent borosilicate glasses for telecommunication and lasing applications

The multicomponent borosilicate (MBSER) glasses activated with different concentrations of Er3+ ions (varies from 0.1 to 2 mol%) were prepared via conventional melting and rapid quench technique and studied their thermal, structural and spectroscopic characteristics by using DSC, XRD, FTIR, optical absorption, excitation and emission measurements. Judd- Ofelt analysis in correlation with the absorption and emission spectral profiles was performed for the evaluation of several radiative parameters of the as-prepared glasses. Visible and NIR luminescence were recorded at 379 nm excitation and a special consideration is given to 1536 nm emission corresponding to the 4I13/2 → 4I15/2 transition. McCumber theory (MC) is used to determine the stimulated emission cross-section from the calculated absorption cross-section and is found well matched with the emission cross-section obtained from Fuchtbauer-Ladenburg (FL) equation. Better radiative parameters (stimulated emission cross-section (σemi) = 15.78 × 10−21cm2, effective bandwidth (Δλeff) = 67 nm), laser (gain bandwidth (σ(λp) x Δλeff = 1.05 × 10−25 cm3), optical gain (σ(λp) x τR) = 42.5 × 10−25 cm2s)) and gain spectra characteristics suggests the MBSER glasses for optical amplifier and laser applications since they offer a broadened emission spectra in the NIR region.

Effect of Increasing Temperature on 1.5 μm Spectroscopic Emission of Er<sup>3+</sup> Ions Activated Phospho-silicate Thin Film

Different concentrations of Er³⁺ ions- embedded nano-composite phospho-silicate ranging from 1 up to 3.5 mol % in thin film, symbolic as (S20P), (S20P1Er)T, (S20P2.5Er)T and (S20P3.5Er)T, respectively were prepared as advanced materials for planar waveguide application. Spin coating sol gel technique will be used to prepare the thin films. The prepared thin films optical and spectroscopic assessments were performed using transmittance, absorption, Raman, photoluminescence and refractive index (n) calculations. The observed transmittance T (%) and reflectance R (%) spectra were measured using Jasco V-570 spectrophotometer, in wavelength range (0.2-2.5 µm), confirmed good transparency for the prepared films, where the T (%) was higher than 92% and S20P1ErT was the most transparent one. The mentioned higher transparency presence was considered as a big challenge, especially after doping the silica gel with such higher phosphorus molar percent up to 20 mol %. Such challenge confirmed that the prepared thin films were suitable for the low losses and active planar waveguide fabrication. The room temperature photoluminescence (RTPL) quenching was observed at lower temperature 100°C for (S20P3.5Er)T. Emission at 1.5 µm upon excitation at 514.5 nm was detected and characteristic to the ⁴I_13/2→⁴I_15/2 erbium ions intra-4F transition for all prepared samples. The morphology of the prepared thin films was examined by using the Field emission scanning electron microscope (FESEM), while the measured film thickness obtained from cross section view from the (FESEM) give rise to 1.791 µm value for (S20P3.5Er)T. The bigger moderate thickness than 1 µm was an adequate parameter for supporting planar optical wave guide applications.

Er3+/Yb3+ co-doped TeO2–ZnO–ZnF2–La2O3 glass with a high fluorescence intensity ratio for an all-fiber temperature sensor

Er3+/Yb3+ co-doped TeO2–ZnO–ZnF2–La2O3 (TZZL) glasses with different concentrations of Er3+ ions were fabricated. Strong green upconversion emission bands centered at 523 and 545 nm induced by 980 nm excitation were observed. The maximum emission intensity of the TZZL glasses was obtained at the Er3+ ion concentration of 0.2 mol%. High-temperature difference (ΔT = 131.8 °C) between the transition and onset crystallization temperatures was confirmed by differential thermal analysis curve. The relationship between fluorescence intensity ratio value and temperature was examined within 303–560 K. The maximum absolute sensitivity (Sa) and the maximum relative sensitivity (Sr) was 0.006 K−1 at 560 K and 0.012 K−1 at 303 K, respectively. A prototype of an all-fiber temperature sensor was designed, and its temperature-sensing performance within 293–383 K was evaluated. Results showed that the absolute errors were within ±1 K, and the largest value of relative standard deviation was approximately 0.2%, suggesting that Er3+/Yb3+ co-doped TZZL glasses have potential applications in optical-fiber temperature sensors.

Upconversion luminescence properties of BaMoO4: Yb3+, Ln3+ (Ln3+ = Er3+/Tm3+, Er3+/Tm3+/Ho3+) micro-octahedrons

Yb3+, Ln3+ (Ln3+ = Er3+/Tm3+, Er3+/Tm3+/Ho3+) doped BaMoO4 micro-octahedrons were synthesized by a hydrothermal process. The as-prepared phosphors were characterized by x-ray powder diffraction, field emission scanning electron microscopy, elemental mapping, energy-dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, and UV–vis diffuse reflectance spectroscopy. The upconversion luminescence properties of the samples were investigated under 980 nm near infrared excitation. The different concentrations of Er3+, Tm3+, and Ho3+ were used for tuning the multicolor (blue, green, and red) emissions. The multicolor emissions were investigated by Commission Internationale de l’Elcairage chromaticity and decay lifetime. The photon process as well as the energy transfer mechanism between the Yb3+ to Er3+, Tm3+, and Ho3+ were described.

Upconversion luminescence of Gd2O3:Er3+ and Gd2O3:Er3+/silica nanophosphors fabricated by EDTA combustion method

Gd2O3:Er3+ nanophosphors were fabricated by the combustion method in presence of Na2 ethylene diamine tetra acetic acid (EDTA-Na2) as fuel at not high temperature (≤350 oC) within a very short time of 5 min. The added concentration of Er3+ ions in Gd2O3 matrix was changed from 0.5 mol% to 5.0 mol%. The X-ray diffraction pattern of samples indicates the monoclinic structure of Gd2O3:Er3+. The morphology and chemical composition analysis of the Gd2O3:Er3+ samples are characterized by a field emission scanning electron microscope (FESEM) and a Fourier-transform infrared spectrometer (FTIR). The photoluminescence (PL), photoluminescence excitation (PLE) and upconversion (UC) at room temperature of the prepared materials with different concentrations of Er3+ were investigated. The PL of Gd2O3:Er3+ nanomaterials are shown in visible at 545, 594, 623, 648, 688 nm under excitation at 275 nm. The emission bands from transitions of Er3+ from 2P3/2 to 4F9/2 are observed. UC luminescent spectra of the Gd2O3:Er3+/silica nanocomposites under 976 nm excitation show the bands at 548 and 670 nm. The influence of excitation power at 980 nm for transitions were measured and calculated. The results indicate that the upconversion process of Gd2O3:Er3+/silica is two photons absorption mechanism. The low temperature dependence of UC luminescent intensities of the main bands of Gd2O3:Er3+ was investigated towards development of a nanotemperature sensor in the range of 10–300 K.

Synthesis, characterization, and magnetic properties of nanosizedZn0:5Co0:5ErxFe2

In the present work, the effect of doping zinc cobalt ferrite by different concentrations of Er3+ on structural, optical, and magnetic properties was studied. Nanosized Zn0.5Co0.5ErxFe2-xO4 (0 ≤ x ≤ 0.2) was synthesized by the coprecipitation method. XRD analysis confirmed the formation of one phase face FCC spinel structure belonging to the Fd3m space group. TEM exhibited that the particle size decreased with the increase of Er3+ content, which is in agreement with XRD results. Two significant absorption bands from FTIR spectra were observed between 400 and 600 cm-1. The band gap energy value obtained from UV-Vis increased with the increasing concentration of Er3+. The decrease of g-value is well correlated with the variation of particle size. All the VSM spectra reveal superparamagnetic behavior. The saturation magnetization decreases continuously while coercivity decreases abruptly with the increase of Er3+ content. The results of this work show the possibility that zinc cobalt ferrite doped by erbium can be useful for magnetic resonance imaging as a biomedicine application.

Structural and photoluminescence properties of UV-excited Er3+ doped Ba2CaWO6 yellowish-green phosphors

Double perovskite Ba2CaWO6 phosphors doped with different concentrations of Er3+ have been synthesized by the conventional solid state reaction method in air at 1250 °C and are characterized by X-ray diffraction analysis (XRD), Energy Dispersive X-ray Spectrometer (EDS), Scanning electron microscope (SEM), Transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) and Photoluminescence measurements. An intense green and weak red emissions are observed at 566 nm (4S3/2 → 4I15/2), 680 nm (4F9/2 → 4I15/2) under 314 nm, 378 nm corresponding to charge transfer band and rare earth excitations respectively. Under charge transfer excitation Ba2CaWO6:xEr3+ samples exhibit high intense emission peaks of Er3+ than the rare earth excitation. This is due to an efficient energy transfer from WO66- to Er3+. The maximum emission intensity was observed for 0.08 wt% concentration of Er3+ ions in Ba2CaWO6 phosphors. The critical energy transfer distance among Er3+ ions is calculated to be 15.18 Å and the quenching mechanism is due to dipole-dipole interaction. The energy transfer mechanism is discussed based on the energy level diagram of Er3+. The radiative lifetimes were determined from the fluorescence decay analysis. The CIE color coordinates were calculated from the emission spectra. The result shows that Ba2CaWO6: Er3+ phosphor can be considered as a potential candidate for UV excited yellowish-green phosphor for display applications.

Enhanced upconversion study of Er3+-Yb3+ codoped NaYF4 phosphors synthesized by the reverse microemulsion method

Herein, nanocrystals of Er3+ and Er3+, Yb3+ co-doped NaYF4 upconversion (UC) phosphor were prepared via the reverse-microemulsion method. The impact of different concentrations of Er3+ ions on the UC emission intensity after 980 nm diode laser excitation is discussed. The structure, morphology and composition of the nanophosphors were confirmed by X-ray diffraction, transmission electron microscopy, scanning electron microscopy and the results showed the presence of NaYF4 nanocrystals with hexagonal phases of NaYF4. The UC spectra revealed two emission bands including a green and a red emission band and the CIE coordinate for the samples were estimated. The present research revealed that the reverse-microemulsion approach will be suitable for the synthesis of efficient upconversion nanophosphors.