Addition Of Yb3 Research Articles

Effect of Yb3+ concentration on the spectroscopic properties of Er3+/Yb3+ co-doped SiO2-TiO2 nanofiber

Er3+ has been gaining much interest due to the multiple emissions in both infrared and visible regions. Based on the previous study, SiO2-TiO2 have been proven to be an excellent host for Er3+. However, Er3+ exhibits a low absorption cross-section when doped into the silica-based host. Therefore, Yb3+ has been introduced into the matrix and acts as a sensitiser to increase the luminescence intensity. Er3+/Yb3+ co-doped 75SiO2-25TiO2 nanofiber with different Er3+/Yb3+ ratios were fabricated via the sol-gel electrospinning method. The FESEM result shows the diameter of the nanofibers in the range of 62 to 515 nm. The absence of any peak within the 3000-4000 cm-1 range in the FTIR spectra indicates the complete removal of the OH group. The XRD results imply that all samples were amorphous. The PL spectra showed strong green emission peaks, which were ascribed to 2H11/2 → 4I15/2 as well as red emission peaks attributed to 4F9/2 → 4I15/2 Er3+ transitions. The PL intensity was varied according to the Yb3+ concentration. The addition of Yb3+ was proven to aid the increment of PL intensity. Nevertheless, the PL intensity reduced when too high of Yb3+ concentration was used due to the concentration quenching effect.

Thermally stable broadband near-infrared emitting pyrochlore oxide phosphors codoped with Cr3+ and Yb3+ ions

The advance of portable and smart near-infrared (NIR) light sources has sparked significant interest. However, achieving high-performance NIR emission at longer wavelengths remains a formidable challenge. In this study, we prepared broadband NIR phosphors by codoping pyrochlore oxide Y2GaSbO7 (YGSO) with Cr3+ and Yb3+ ions using a conventional high-temperature solid-state reaction. Upon excitation by blue light, YGSO: 0.03Cr3+ exhibited a broadband NIR emission centered at 765 nm with a full width at half maximum (FWHM) of 160 nm. The purposeful incorporation of Yb3+ ions facilitated efficient energy transfer from Cr3+ to Yb3+, resulting in a newly observed NIR emission peak at 970 nm. Notably, the addition of Yb3+ improved the overall thermal quenching resistance owing to its inherent thermal stability. Furthermore, we encapsulated the as-obtained phosphors with commercial blue LED chips to create prototype phosphor-converted light-emitting diodes (pc-LEDs). The Cr3+ and Cr3+-Yb3+ codoped pc-LEDs achieved output powers of 120 mW@660 mA with a photoelectric conversion efficiency of 12.66%@30 mA, and 131.7 mW@1020 mA with a photoelectric conversion efficiency of 13.93%@30 mA, respectively. These broadband NIR pc-LEDs hold promise for optical imaging applications.

Tailoring near-infrared luminescence with Er3+/Tm3+/Yb3+ tri-doped tellurite glasses for applications in the C, L and U bands

In this work, co-doped and tri-doped systems with Er3+, Tm3+ and Yb3+ were evaluated in tungsten-tellurite glasses to extend the amplification range of current Erbium-Doped Fiber Amplifiers (EDFAs). The conditions of synthesis showed that the use of appropriate atmosphere was efficient to decrease the OH content and enhance the Er3+ emission. Spectroscopic studies on Er3+ and Tm3+ co-doped glasses revealed an emission from 1500 to 2000 nm with the energy transfer between both ions and the luminescence from Er3+: 4I13/2 → 4I15/2 and Tm3+:3F4 → 4H6. The addition of Yb3+ increased around 4 times in the NIR luminescence at 1535 nm. Lifetime measurements showed an increase of energy transfer efficiency (η) from Er3+ to Tm3+ as Tm2O3 content increased. In addition, temperature-dependent luminescence is studied for co-doped and tri-doped systems in the range of −180 to 75 °C. As temperature decreases, the ratio between Er3+ and Tm3+ emissions increases whereas the introduction of Yb3+ considerably enhanced the emission from Er3+ at 1535 nm related to Tm3+. This study demonstrates that the NIR emission of these tellurite glasses, both in intensity and bandwidth, can be considerably tailored by means of the dopant content, synthesis conditions, and temperature.

Hydrothermal synthesis and upconversion luminescence of cubic-shaped LiNbO3:Yb3+/Er3+ nanocrystals

We exploited a simple hydrothermal route without adding organic additives or hard templates to synthesize cubic-shaped LiNbO3:Yb3+/Er3+ with the size of 400–500 nm. Based on the time-dependent investigation on the crystal structure and morphology, Yb(NO3)3 and Er(NO3)3 not only could emit green and red upconversion (UC) emission but also could be used as an etchant to increase dissolution rate of the Nb2O5 raw material in the hydrothermal synthesis route. Without addition of Yb3+/Er3+ ions, LiNbO3 phase could not be formed at even hydrothermal time of 48 h. The time-dependent Raman spectra showed the Raman peaks of LiNbO3 were occurred at the reaction time of 48 h, and the impurity Nb2O5 phase was disappeared with lengthening hydrothermal time. After calcining at 1050 °C for 2 h, the new Raman peaks at 440/487/531/552 cm−1 and the disappeared OH– absorption peaks at 3429 and 1628 cm−1 favored to produce the bright UC emissions in LiNbO3:Yb3+/Er3+ nanocrystals. The pump power dependence and UC mechanism were studied under 980 nm excitation.

The Upconversion Luminescence of Ca3Sc2Si3O12:Yb3+,Er3+ and Its Application in Thermometry.

To develop novel luminescent materials for optical temperature measurement, a series of Yb3+- and Er3+-doped Ca3Sc2Si3O12 (CSS) upconversion (UC) phosphors were synthesized by the sol-gel combustion method. The crystal structure, phase purity, and element distribution of the samples were characterized by powder X-ray diffraction and a transmission electron microscope (TEM). The detailed study of the photoluminescence emission spectra of the samples shows that the addition of Yb3+ can greatly enhance the emission of Er3+ by effective energy transfer. The prepared Yb3+ and Er3+ co-doped CSS phosphors exhibit green emission bands near 522 and 555 nm and red emission bands near 658 nm, which correspond to the 2H11/2→4I15/2, 4S3/2→4I15/2, and 4F9/2→4I15/2 transitions of Er3+, respectively. The temperature-dependent behavior of the CSS:0.2Yb3+,0.02Er3+ sample was carefully studied by the fluorescence intensity ratio (FIR) technique. The results indicate the excellent sensitivity of the sample, with a maximum absolute sensitivity of 0.67% K-1 at 500 K and a relative sensitivity of 1.34% K-1 at 300 K. We demonstrate here that the temperature measurement performance of FIR technology using the CSS:Yb3+,Er3+ phosphor is not inferior to that of infrared thermal imaging thermometers. Therefore, CSS:Yb3+,Er3+ phosphors have great potential applications in the field of optical thermometry.

LiGaP2O7:Cr3+, Yb3+ phosphors for broadband NIR LEDs toward multiple applications

Developing high-performance broadband near-infrared (NIR) phosphors for NIR phosphor-converted light-emitting diodes (pc-LEDs) is still a challenge. Co-doping is an effective strategy to enhance performances of the NIR phosphors. Herein, we explore a novel NIR phosphor by co-doping Yb3+ into LiGaP2O7:Cr3+ (LGAP:Cr3+) and systematically analyse its microtopography. Under 450 nm excitation, LGAP:Cr3+,Yb3+ emits a broad NIR band from 700 to 1100 nm. Due to the energy transfer from Cr3+ to Yb3+, the Yb3+ emission is strengthened more than 8 times and the external quantum efficiency reaches 25.5%. The addition of Yb3+ suppresses the thermal quenching compared with the Cr3+ single-doped specimen. The LGAP:Cr3+,Yb3+ phosphors and commercial blue chips are used to fabricate the NIR pc-LED. At 100 mA, the NIR pc-LED manifests an output NIR power of 24.86 mW and a photoelectric conversion efficiency of 8.30%, demonstrating possible applications in night version and bioimaging.

Hydrothermal Synthesis and Properties of Yb3+/Tm3+ Doped Sr2LaF7 Upconversion Nanoparticles

We report the procedure for hydrothermal synthesis of ultrasmall Yb3+/Tm3+ co-doped Sr2LaF7 (SLF) upconversion phosphors. These phosphors were synthesized by varying the concentrations of Yb3+ (x = 10, 15, 20, and 25 mol%) and Tm3+ (y = 0.75, 1, 2, and 3 mol%) with the aim to analyze their emissions in the near IR spectral range. According to the detailed structural analysis, Yb3+ and Tm3+ occupy the La3+ sites in the SLF host. The addition of Yb3+/Tm3+ ions has a huge impact on the lattice constant, particle size, and PL emission properties of the synthesized SLF nanophosphor. The results show that the optimal dopant concentrations for upconversion luminescence of Yb3+/Tm3+ co-doped SLF are 20 mol% Yb3+ and 1 mol% Tm3+ with EDTA as the chelating agent. Under 980 nm light excitation, a strong upconversion emission of Tm3+ ions around 800 nm was achieved. In addition, the experimental photoluminescence lifetime of Tm3+ emission in the SLF host is reported. This study discovered that efficient near IR emission from ultrasmall Yb3+/Tm3+ co-doped SLF phosphors may have potential applications in the fields of fluorescent labels in bioimaging and security applications.

A novel self-activated ultraviolet persistent luminescence material and its anti-counterfeiting application based on intensity and time resolution from persistent luminescence

Recently, the ultraviolet (UV) persistent luminescence material (PLM) has attracted extensive attention. However, the design and development of new UV PLM and exploring their promising advanced application remain challenges. Here, we developed a new dopant-free self-activated UVA PLM, Zn2Al2SiO7, which could be applied in anti-counterfeiting field. Zn2Al2SiO7 shows UVA persistent luminescence (PersL) peaking at 380 nm after 254 nm UV lamp excitation. Addition of Yb3+, the UVA PersL intensity and time are raised obviously, and the UVA PersL time lasts more than 24 h. In addition, Yb3+-doped Zn2Al2SiO7 exhibits photostimulated properties with different light source. Finally, we design anti-counterfeiting pattern based on intensity and time resolution from PersL of Zn2Al2SiO7, showing its advantages in the anti-counterfeiting field.

Up-conversion luminescence properties and temperature sensing performances of Ba5Y8Zn4O21:Yb3+, Er3+ phosphors

A serials of Er3+ single-doped and Yb3+, Er3+ co-doped Ba5Y8Zn4O21 phosphors were manufactured through high-temperature solid-state reaction technique to explore the application for optical thermometer. In the course of experiment, the samples were designed based on the orthogonal experimental method to find the optimal sample with the strongest green emission that can bring in high measurement accuracy. The relationship between doping content and luminescent intensity was systematically explored and the variation tendencies of green and red emission intensity were presented intuitively. Er3+ single-doped phosphors exhibit bright up-conversion emission under stimulation of 980 nm laser. With the addition of Yb3+, the characteristic emission intensity of Er3+ was greatly enhanced. Based on the luminescent features, the power dependent spectra and the energy structure of Yb3+ and Er3+, conceivable luminescent mechanism was deduced. Meanwhile, the temperature sensing behaviors were explored by the temperature dependent up-conversion spectra. The maximum relative sensitivity (SR) is 1.36 × 10−2 K−1 (at 293 K). The above investigations manifest that the Yb3+, Er3+ co-doped Ba5Y8Zn4O21 phosphors have potential applications for optical thermometer.

Enhancing the electrical properties of NBT ceramics by the addition of small amounts of Yb

In the present work, the magnetic and electrical properties of ceramic samples of Na0.5Bi0.5−xYbxTiO3 with x = 0.005, 0.010, 0.015 and 0.020 prepared by a solid-state reaction were investigated. X-ray diffraction (XRD) patterns revealed that the addition of Yb3+ ions led to distortions in the rhombohedral perovskite structure. The microstructure morphology investigated by scanning electron microscopy revealed the presence of micro-pores, diminishing the overall mass density of the ceramics for increasing values of x. This behaviour is opposite to the one observed for the mass density determined by using the XRD data. Despite of the contraction in the lattice parameter, the<Ti–O>bond length was found to increase for increasing values of x, shifting the corresponding Raman modes towards lower values of energy. The magnetization and the ac and dc magnetic susceptibilities were measured from 300 K down to 5 K. The magnetic moment associated to the Yb3+ ions added a paramagnetic behavior to the NBT samples that increases for increasing values of x. The electrical permittivity was measured at room temperature by impedance spectroscopy for frequencies (f) in the range 20 Hz–2.0 GHz. The f-dependence for the permittivity was accounted for by using the Cole-Davidson model. It was observed that the addition of the Yb3+ ions enhances the values of the dielectric constants, yielding an increase of about 70% for x = 0.020, while the overall dielectric losses are significantly reduced.

A three-mode self-referenced optical thermometry based on up-conversion luminescence of Ca2MgWO6:Er3+,Yb3+ phosphors

To develop new up-conversion luminescent materials for optical thermometry, a sequence of Ca2MgWO6:xEr3+,yYb3+ phosphor samples were synthesized via high temperature solid-state reaction method. Their structure, morphology and luminescent performances were completely explored via X-ray diffraction, scanning electron microscopy and photoluminescence. Excited by 980 nm laser, all phosphor samples emit intense up-conversion luminescence of Er3+ at 531, 549 and 661 nm. Besides, these emissions were greatly enhanced with addition of Yb3+ ions. Benefiting from the different temperature dependence of three emission peaks, a dual-mode temperature sensor based on fluorescence intensity ratio (2H11/2/4S3/2 and 2H11/2/4F9/2) is realized by using single luminescent center. Meanwhile, the fluorescence lifetime of 4S3/2 state of Er3+ ions was used as the third temperature detection signal. More importantly, the phosphors exhibit superior thermal stability that will be helpful to obtain high precision temperature measurement. All results show that Ca2MgWO6:Er3+, Yb3+ samples could have potential applications for self-referenced optical thermometry.

Spectroscopic properties of Yb3+ and Nd3+ co-doped tellurite glass for 1.0 μm laser application

The Nd3+/Yb3+ co-doped tellurite glasses were prepared using the traditional melt quenching method. The spectroscopic properties of 1.0 μm emission in Nd3+/Yb3+ co-doped tellurite glasses were studied under 808 nm excitation. The concentration effect of Yb3+ ions on emission spectra of tellurite glass singly doped with Nd3+ ions was investigated. The results showed that the intensity and full-width-at-half-maximum (FWHM) of the emission spectra change with the addition of Yb3+ ions, and the luminescence lifetime increased from 0.18 ms to 0.83 ms as the Yb3+ ions content rise from 0 to 6.0 (mol%). Besides, there was an improvement in the quantum yield of co-doped glass (from 0.31 to 0.82), as the Yb3+ ions increased from 0 to 5.0 (mol%). Moreover, laser generation of Nd3+/Yb3+ co-doped tellurite glass around 1.02 μm was attained. All results indicate the potential applications of this Nd3+/Yb3+ co-doped tellurite glass in laser materials.

Influence of transition metal ions: Broad band upconversion emission in thermally stable phosphors

Abstract Frequency upconversion (UC) study at different temperatures in Ho3+/Yb3+/Mn4+:SnO2 phosphors, prepared via solid state reaction method has been performed. The prepared phosphors have been characterized via XRD, Raman spectra, FESEM, EDAX, XPS and diffuse reflectance analysis. The decrease in bandgap has been reported due to codoping with Mn4+ ions in the developed phosphors. An enhancement of about 47 and 6 times in the green and red UC emission bands has been observed with the addition of Yb3+ ions. Moreover, incorporation of Mn4+ ions gives broad visible UC emission ranging from 400 nm to 900 nm. The mechanism responsible for the enhancement and broad band UC emission has been discussed on the basis of pump power dependence followed by the photon avalanche energy transfer process.

Spectroscopic properties of Er/Yb co-doped glass ceramics containing nanocrystalline Bi2ZnB2O7 for broadband near-infrared emission

Abstract Er/Yb co-doped transparent glass ceramics containing nanocrystalline Bi2ZnB2O7 were successfully prepared by a high-temperature melting method. X-ray diffraction analysis confirmed the structural properties of the crystal and glass phases of the glass ceramics. Scanning electron microscope images indicated that nanocrystalline Bi2ZnB2O7 with an average size of 30–40 nm was uniformly distributed in the glass matrix. Infrared spectroscopy demonstrated that the glass and glass ceramics had different vibrational peaks. The absorption spectra showed the absorption peaks of the samples, and the main spectral parameters of each absorption peak were calculated using the Judd–Ofelt theory. The emission spectra of the samples showed ultra-wideband fluorescence from 1400 to 1700 nm under excitation at 980 nm, which was enhanced by precipitation of nanocrystalline Bi2ZnB2O7 and the addition of Yb3+ ions. Our research showed that Er/Yb co-doped glass ceramics containing nanocrystalline Bi2ZnB2O7 are a promising material for application in near-infrared optical amplifiers.

Enhancement of photodegradation efficiency, photoluminescence quantum yield, and magnetization in highly Yb3+-doped CdO nanoparticles synthesized via sol–gel method

Cd1−xYbxO (x = 0, 1, 5, 10, 15 mol%) nanoparticles (NPs) were successfully synthesized by pulverizing the product obtained from a sol–gel process. The crystalline structure of the synthesized samples was established by X-ray diffraction analysis. Scanning electron microscopy revealed that the prepared samples were nanoscale and the size of the NPs decreased with increasing dopant concentration. Elemental analysis of the products was carried out by energy-dispersive X-ray spectroscopy. Ultraviolet–visible (UV–Vis) and Fourier-transform infrared (FT-IR) spectroscopies were used to characterize the synthesized species. Increasing the Yb3+ ion level in the host matter resulted in decreased bandgap energy. Photoluminescence measurements confirmed the enhanced intensity of the characteristic emissions in the Yb3+-doped CdO NPs, indicating appropriate substitution of Cd2+ with Yb3+ ions. Magnetic measurements revealed that, with addition of Yb3+ ion, the magnetic behavior of the samples changed. Increasing the dopant ion concentration, thereby decreasing the size of the obtained NPs, changed their behavior from paramagnetic to superparamagnetic, with increased saturation magnetization (MS) for higher dopant level. Photocatalytic measurements under UV and natural sunlight irradiation revealed that the samples prepared with high dopant concentration (15 mol%) exhibited excellent photocatalytic activity under natural sunlight for decomposition of methylene blue dye.

Preliminary evaluation of the up-conversion emission of Y2O3:Er-Yb thin films prepared by a solid state photochemical deposition method

Y2O3 thin films doped with different concentrations of erbium ions and co-doped with 10 mol% of ytterbium were synthesized by a solid state photochemical deposition method followed by a subsequent calcination process. The photo-reactivity of the thin films was monitored by Fourier transform infrared (FT-IR) spectroscopy. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), UV–vis spectroscopy and photo-luminescence (PL) were employed to characterize the samples. The results reveal that Y2O3:Er films under 980 nm irradiation exhibit characteristic up-conversion emissions that are focused in the green region of the spectrum; these emissions are assigned to the (2H11/2, 4S3/2)→4I15/2 transitions of the Er3+ ions. These emissions greatly increase in intensity with the addition of Yb3+ ions in the preparation of the co-doped films. This phenomenon is explained based on the efficient Yb3+ → Er3+ energy transfer processes.

Energy-transfer Er3+ to Eu3+ and frequency upconversion visible emission in PbGeO3:PbF2:CdF2 glass

Er3+ to Eu3+ energy-transfer and frequency upconversion in PbGeO3:PbF2:CdF2 glass are reported. Emission spectra excited at 980 nm was obtained for Er3+-doped samples, while Eu3+ emissions only occurred for double-doped (Er3+/Eu3+) or triple-doped (Yb3+/Er3+/Eu3+) samples. Codoped samples’ spectra exhibit bands around 520 (2H11/2 – 4I15/2), 545 (4S3/2 – 4I15/2), 590 (5D0 – 7F1), 610 (5D0 – 7F2), 660 (4F9/2 – 4I15/2) and 700 (5D0 – 7F4) nm. The Er3+ green emissions’ lifetimes were examined as a function of Eu3+ content evidencing Er3+-to-Eu3+ energy-transfer. The addition of Yb3+ enhanced the Eu3+ ions’ emissions suggesting potential application for upconversion-based white light phosphor.

Role of ytterbium on structural and magnetic properties of NiCr0.1Fe1.9O4 co-precipitated ferrites

Ytterbium (Yb) doped NiCr0.1YbxFe1.9−xO4 (x = 0.00, 0.002, 0.04, 0.06, 0.08) spinel ferrites with different crystallite sizes have been prepared by co-precipitation technique and their magnetic and dielectric properties were investigated. X-ray diffraction data suggested that, after doping, all the samples possess a main spinel phase along with few traces of YbFeO3 (secondary phase). The addition of Yb3+ resulted in a decrease of crystallite size and an increase in X-ray density. The magnetic measurements indicated that saturation magnetization (Ms), coercivity (Hc) and remanence (Mr) of all the samples decreased by increasing dopant (Yb) concentration. Dielectric constant, dielectric loss and tan loss were also minimized with the increase in frequency as well as increase in the concentration of Yb3+ ions in the nickel chromium based spinel ferrites. AC conductivity was directly proportional to frequency and inversely proportional to concentration of Yb3+ ions. These ytterbium doped nickel ferrites may be potential candidates for the fabrication and development of high frequency switching devices.

Blue to NIR down-conversion in Tm3+/Yb3+-codoped fluorozirconate glasses compared to Pr3+/Yb3+ ion-pair

Visible to near infrared down-conversion has been studied in Tm3+/Yb3+-codoped fluorozirconate glasses, namely ZBLA (57ZrF4-34BaF2-5LaF3-4AlF3 in mol%) and ZLAG (70.2ZrF4-23.4LaF3−0.6AlF3-5.8GaF3 in mol%). Upon blue excitation at 467nm, Tm3+ doped glasses yield weak red at 650nm and strong luminescence around 800nm. With the addition of Yb3+, emission between 950 and 1100nm from the Yb3+: 2F5/2 → 2F7/2 transition was observed. This emission well matched with the band gap of crystalline silicium. The mechanism responsible for down-conversion in the Tm3+/Yb3+ ion-pair is a down-shifting process. The highest energy transfer efficiency ηETE was 64.5% in ZBLA glasses doped with 0.75Tm3+/10Yb3+; this efficiency was mainly limited by the strong Yb3+ to Tm3+ back energy transfer. ηETE appeared to increase more rapidly with the addition of Yb3+ in ZLAG glasses, as already observed for the energy transfer in Pr3+/Yb3+ ion-pair. The origin of the difference between the two hosts is probably related to the distribution of rare-earth ions in the host matrix, as shown by molecular dynamics simulation.The Tm3+/Yb3+ system is found much less efficient that the Pr3+/Yb3+ one, because of less efficient quantum efficiency together with lower blue absorption of Tm3+ compared to Pr3+.

Enhanced Quantum Cutting via Li+ Doping from a Bi3+/Yb3+-Codoped Gadolinium Tungstate Phosphor.

The Bi3+/Yb3+-codoped gadolinium tungstate phosphor has been synthesized through a solid-state reaction method. The structural characterization reveals the crystalline nature of the phosphor. The Bi3+-doped phosphor emits visible radiation from the blue to red regions upon excitation with 330 and 355 nm. The addition of Yb3+ to the Bi3+-doped phosphor reduces the emission intensity in the visible region and emits an intense near-infrared (NIR) photon centered at 976 nm through a quantum-cutting (QC) phenomenon. This is due to cooperative energy transfer (CET) from the 3P1 level of Bi3+ to the 2F5/2 level of Yb3+. The presence of Li+ ions in the Bi3+/Yb3+-codoped phosphor enhances the emission intensity in the NIR region up to by 3 times, whereas the emission intensity in the visible region is significantly reduced. The energy transfer (ET) from the Bi3+ ions to the Yb3+ ions is confirmed by lifetime measurements, and the lifetime for the 3P1 level of Bi3+ decreases continuously with increasing Yb3+ concentration. The ET efficiency (ηETE) and corresponding QC efficiency (ηQE) are calculated and found to be 29% and 129%, respectively. The presence of Li+ enhances the QC efficiency of the phosphor up to 43%. Thus, the Bi3+/Yb3+/Li+-codoped phosphor is a promising candidate to enhance the efficiency of a crystalline-silicon-based solar cell through spectral conversion.