Nm For Yb Research Articles

Efficient Near-Infrared Quantum Cutting in Y2O3 co-doped with Ho3+, Yb3+ Phosphor for the Application in Solar Cell

Abstract: An efficient Near-Infrared Quantum Cutting has been demonstrated in Ho3+ and Yb3+ co-activated Y2O3 sample, synthesized by a complex based precursor solution method. The phosphors have been characterized by X-ray diffraction (XRD), Crystal structure photoluminescence (PL) and CIE Chromaticity analysis. The phosphor materials give efficient emission in the green region both through UC and PL, while efficient NIR emission is observed through the QC process. The Photoluminescence emission (PL) spectra of Y2O3 doped 1% Ho3+ x% Yb3+ (x= 0, 5, 10, 20, 30, and 50) samples, The cooperative energy transfers from one Ho3+ to two Yb3+, an intense NIR emission around 549 nm of Yb3+ 2F5/2 - 2F7/2 transition was obtained under 449 nm excitation. Near infrared photons (wavelength range 549 nm) emitted by an Yb3+ ion pair. The Properties of Y2O3 doped with Ho3+ and Yb3+ quantum-cutting phosphors are dependent on various factors such as dopant concentration, crystallinity, homogeneity, particle size. Effective control of the above parameters the quantum-cutting ability of the phosphor material. Small particle size of the quantum-cutting phosphor Y2O3:Ho3+, Yb3+ make it a suitable candidate for its application in solar cells.

Optical transition properties, 1550-to-980 nm upconversion, and temperature sensing of NaEr(WO4)2:Yb3+ phosphors synthesized via the microwave-assisted hydrothermal method

Improving photoelectric conversion efficiency and enhancing heat management are two critical considerations for silicon-based solar cells. In this study, efficient Yb3+ infrared emissions through the upconversion process were achieved by adjusting the concentrations of Yb3+ in Er3+ highly condensed NaEr(WO4)2 phosphor. Additionally, the temperature sensing based on the fluorescence intensity ratio (FIR) was also studied in this tungstate system. Moreover, the radiative transition rates for all relevant transitions of Er3+ in NaEr(WO4)2:Yb3+ phosphors were calculated in the framework of Judd-Ofelt theory, and the optical transition properties of Yb3+ were also revealed by taking Er3+ as a reference. It was found that the radiative transition rate of Yb3+:2F5/2→2F7/2 (2977.52s−1) is significantly higher than that of Er3+:4I11/2→4I15/2 (303.50s−1), thus suggesting the feasibility for the strong emission at 980 nm of Yb3+ in assistance of the energy transfer 4I11/2+2F7/2→4I15/2+2F5/2. Finally, strong and nearly pure NIR emissions of Yb3+ were experimentally observed under 1550 nm excitation, and possible upconversion mechanisms were proposed. The temperature sensing performance of the studied materials was also assessed. All the results imply that NaEr(WO4)2:Yb3+ constitutes an excellent material for enhancing both the photoelectric conversion efficiency and thermal management of silicon-based solar cells.

Multiple emission bands NIR-persistent luminescence mSiO2@Zn0.6Ca0.4Ga2O4:Cr3+,Yb3+ nanoparticles for biological applications.

Persistent luminescence nanoparticles (PLNPs) emitting in the NIR window (700-1700 nm) have shown great promise in the field of fluorescence imaging due to their unique properties, including the absence of in situ excitation and low optical scattering in tissues. However, they are still facing some challenges, such as irregular shape, wide size distribution and poor persistent luminescence performance. Here, we report a facile mesoporous template method for synthesizing mSiO2@Zn0.6Ca0.4Ga2O4:Cr3+,Yb3+ (mSiO2@ZCGO) persistent luminescent nanoparticles, which show a regular morphology and a size of about 69 nm. In addition, these nanocrystals exhibit persistent luminescence in multi-NIR windows, the first infrared window (∼696 nm of Cr3+ emission) and second infrared window (∼1000 nm of Yb3+ emission). Under illumination of a 254 nm UV lamp for 10 min, the persistent time of Cr3+ ions and Yb3+ ions lasted more than 120 min and 10 min, respectively. In particular, the NIR persistent emission of mSiO2@ZCGO could be stimulated by soft X-ray, which is beneficial to long-term imaging in deep tissues. The optical penetration length of Yb3+ ions persistent luminescence was evaluated to be 2.8 mm. These results demonstrate the great promise of mSiO2@ZCGO for deep-tissue bio-imaging.

Luminescent Sensor Based on Ln(III) Ternary Complexes for NAD(P)H Detection.

Ln(III) complexes of macrocyclic ligands are used in medicinal chemistry, for example as contrast agents in MRI or radiopharmaceutical compounds, and in diagnostics using fluorescence imaging. This paper is devoted to a spectroscopic study of Ln(III) ternary complexes consisting of macrocyclic heptadentate DO3A and bidentate 3-isoquinolinate (IQCA) ligands. IQCA serves as an efficient antenna ligand, leading to a higher quantum yield and Stokes shift (250–350 nm for Eu, Tb, Sm, Dy in VIS region, 550–650 nm for Yb, Nd in NIR region). The shielding-quenching effect of NAD(P)H on the luminescence of the Ln(III) ternary complexes was investigated in detail and this phenomenon was utilized for the analytical determination of this compound. This general approach was verified through an enzymatic reaction during which the course of ethanol transformation catalyzed by alcohol-dehydrogenase (ADH) was followed by luminescence spectroscopy. This method can be utilized for selective and sensitive determination of ethanol concentration and/or ADH enzyme activity. This new analytical method can also be used for other enzyme systems coupled with NAD(P)H/NAD(P)+ redox pairs.

Green synthesis of ionic liquid assisted ytterbium oxide nanoparticles by Couroupita guianensis abul leaves extract for biological applications

• The Yb 2 O 3 and IL-Yb 2 O 3 noparticles were prepared in hydrothermal method by Couroupita guianensis abul leaves extract. • The synthesized Yb 2 O 3 , IL-Yb 2 O 3 NPs have BCC structure and crystalline size of 40 and 35 nm. • The chemical states and elements confirmed by XPS and EDX spectroscopy. • The anti-inflammatory activities of IL-Yb 2 O 3 showed higher inhibition (%) than Yb 2 O 3 and diclofenac sodium. • The antioxidant assay of IL-assisted Yb 2 O 3 NPs has a higher effect than Yb 2 O 3 . Rare earth element ytterbium oxide (Yb 2 O 3 ) and ionic liquid (IL) added ytterbium oxide (Yb 2 O 3 -IL) nanoparticles (NPs) were synthesized using Couroupita guianensis abul leaves extract by hydrothermal method. The synthesized Yb 2 O 3 and Yb 2 O 3 -IL NPs are of BCC structure and crystalline size of 40 and 35 nm. Functional group and vibrational mode were analyzed by FTIR and Raman spectroscopy and the resultant Yb-O stretching peak at 618 and 588 cm −1 . The optical absorption at 239 and 230 nm for Yb 2 O 3 and Yb 2 O 3 -IL NPs were studied by UV–vis spectroscopy. The relative high-intensity emission peaks at 424 (blue) and 583 (yellow) were confirmed by photoluminescence spectroscopy. The particle size of Yb 2 O 3 -IL observed in the range of around 15–37 nm was confirmed by DLS method and the results matched with SEM analysis. The Yb, O 1s and C 1s states and the corresponding binding energy (BE) values were confirmed by X-ray photoelectron spectroscopy. The hexagonal, spherical and rectangular shapes were identified by SEM and TEM analyses. Biological activities such as antibacterial against E. coli and S. aureus, anti-cancer against MCF-7 breast cancer cells, anti-inflammatory against bovine serum albumin denaturation with standard diclofenac and anti-oxidant against free radical scavenging assay with Vitamin C were also studied for the synthesized Yb 2 O 3 and Yb 2 O 3 -IL NPs.

Efficient energy transfer between Nd3+ → Yb3+ codoped Gd2O2S host for NIR emission

Novel near infrared (NIR) emitting phosphor, Gd2O2S codoped with Nd3+ and Yb3+ was synthesized by one step combustion synthesis and characterized with X-ray diffraction, photoluminescence emission, photoluminescence excitation spectra and fluorescence decay measurements. The good connectivity with grains and the semi-sphere line structure was found by TEM. The functional group analysis was carried out by Fourier transform infrared (FTIR) spectroscopic techniques. The prepared phosphor gives emission spectra in NIR region centred at 978 nm for Yb3+ and at 890 nm, 1065 nm, 1320 nm for Nd3+ doped samples. For codped samples the peaks at 890 nm and 1320 nm have been eliminated. The emission was recorded under 800 nm excitation and an efficient Nd3+ → Yb3+ resonant and phonon-assisted energy transfer processes have been observed. It have been studied using steady-state and time-resolved optical spectroscopies. Results indicate that the energy transfer occurs via nonradiative electric dipole–dipole processes and is enhanced with the concentration of Yb3+ acceptor ions, having an efficiency higher than 75% for the glass doped with 1 mol% of Nd2O3 and 4 mol% of Yb2O3.

Eye safe emission in Tm3+/Ho3+ and Yb3+/Tm3+ co-doped optical fibers fabricated using MCVD-CDS system

The RE-co-doped silica optical fibers emitting in the eye-safe spectral range are still attractive for new applications like LIDAR, pollution monitoring, navigation, and free-space optical communication. High gain and beam quality of fiber sources based on large mode area (LMA) active fibers can be fabricated by the well-known Modified Chemical Vapor Deposition (MCVD) technology improved by the chelate doping system. Considering silica matrix, the most interesting co-dopants in the region above 1400 nm are thulium and holmium. In the paper Tm3+/Ho3+ and Yb3+/Tm3+ co-doped silica optical fibers (refractive index and rare earth distribution profile, luminescence) are presented. Their respective emission spectra has been measured over the range 1550–2150 nm for Tm3+/Ho3+ (exc. at 796 nm) and 1600–2100 nm for Yb3+/Tm3+ (exc. at 976 nm). A wide luminescent spectrum has been recorded from RE co-doping of silica glass during the MCVD process and we were able to achieve the appropriate and uniform concentration for getting the conditions of energy transfer. The fabrication and characterization of Tm3+/Ho3+ and Yb3+/Tm3+ co-doped optical fibres are presented. The analysis of luminescence spectrum changes vs. fibre length has shown that there is Amplified Spontaneous Emission (ASE) at 1960 nm in Yb3+/Tm3+ co-doped optical fibre. The possibilities of obtaining novel constructions of RE co-doped optical fibers for eye-safe emission region will be also shown.

Er3+-to-dye energy transfer in DNA-coated core and core/shell/shell upconverting nanoparticles with 980 nm and 808 nm excitation of Yb3+ and Nd3.

The capability of upconverting nanoparticles (UCNPs) to convert near infrared (NIR) into visible light has become an important feature for biosensing, imaging, therapy, and their combination. While significant achievements have been accomplished during the last decade developing nanohybrids based on UCNPs as energy donors in Förster resonance energy transfer (FRET) systems, it is still challenging to understand and control FRET from UCNPs to dyes and to adapt the NIR excitation wavelength. Here, we describe the synthesis, characterization, and steady-state and time-resolved FRET analysis of UCNP-DNA nanohybrids, in which dye labelled single stranded (ss)DNA was attached to Yb-Er-co-doped core UCNPs (c-UCNPs) and c-UCNPs with a thin Nd-doped shell and a second thin undoped shell (css-UCNPs). Despite differences in sizes, compositions, donor-acceptor distances, brightness, and excitation wavelength (980 nm for Yb3+ and 808 nm for Nd3+), all UCNP-DNA nanohybrids showed very similar concentration dependent FRET-quenching of UCNP luminescence with efficiencies between 0 and ∼20%. We analyzed luminescence intensities, decay times, and rise times and could show the entanglement of excitation and emission kinetics by simply changing the excitation wavelength from 980 nm to 808 nm for the same css-UCNPs. Time-gated FRET-sensitized dye luminescence showed dye-ssDNA concentration dependence over four orders of magnitude (1 nM to 10 μM), which suggested a possible application to nucleic acid biosensing for both 808 and 980 nm excitation.

Effects of La3+ on the enhancement NIR quantum cutting and UC emissions in Nd3+–Yb3+ co-doped transparent silicate glass-ceramics for solar cells

Near-infrared (NIR) quantum cutting (QC) and upconversion (UC) emission of Nd3+–Yb3+ co-doped in Si–Al–Ba–La transparent silicate glass-ceramics (SGC) were prepared. Influence of La3+ on the enhancement NIR QC and UC emission intensity of the co-doped Nd3+–Yb3+ in SGC were investigated. Thereby, NIR QC and UC emission intensity of the co-doped Nd3+–Yb3+ were increased strongly with increasing concentration of LaF3 from 5 up to 25 mol. %. The value of NIR QC emission intensity of the co-doped Nd3+–Yb3+ band centered at ~890, 947, 1071, 1339 and 1430 nm is maximized when the concentration of LaF3 reaches 25 mol. %. At the same time, with the increasing concentration of Yb3+, NIR QC emission intensity of the co-doped Nd3+–Yb3+ bands centered at ~890, 1071, 1339 and 1430 nm of Nd3+ and 947 nm of Yb3+ were gradually increased and reaches its maximum at 2.5 mol. % Yb3+, then decreased owing to the self-quenching effect. In addition, NIR QC mechanism and energy transfer (ET) processes between 2F5/2 → 2F7/2 transition of Yb3+ and transitions of Nd3+ are discussed.

Fabrication and microstructure development of Yb:YAG transparent ceramics from co‐precipitated powders without additives

AbstractSintering additives are generally considered to be important for improving densification in fabrication of transparent ceramics. However, the sintering aids as impurities doped in the laser materials would decrease the laser output power and produce additional heat during laser operation. In this work, Yb:YAG ceramics were vacuum‐sintered without additives at different temperatures for various soaking time through using ball‐milled powders synthesized by co‐precipitation route. The densification behavior and grain growth kinetics of Yb:YAG ceramics were systematically investigated through densification curves and microstructural characterizations. It was determined that the densification in the 1500°C‐1600°C temperature range was controlled by a grain‐boundary diffusion. It is revealed that the volume diffusion is the main mechanism controlling the grain growth between 1600°C and 1750°C. Although SiO2 additives can promote densification during low‐temperature sintering, the optical transmittance of Yb:YAG ceramic with no additives, sintered at 1800°C for 15 hours, reaches a maximum of 83.4% at 1064 nm, very close to the measured transmittance value of Yb:YAG single crystal. The optical attenuation loss was measured at 1064 nm in Yb:YAG transparent ceramic, to be 0.0035 cm−1, a value close to that observed for single crystals.

Ultra-broadband 1.0 μm band emission spectroscopy in Pr3+/Nd3+/Yb3+ tri-doped tellurite glass.

Tellurite glasses doped with trivalent Pr3+, Nd3+ and Yb3+ ions were prepared using conventional high-temperature melt-quenching technique and their optical absorption, near-infrared emission, X-ray diffraction (XRD), Raman spectrum, and differential scanning calorimeter (DSC) curve were measured. Upon excitation at 488 nm, an ultra-broadband near-infrared emission extending from 800 to 1120 nm was found to appear owing to the overlapping of the emission bands centered at 900 and 1035 nm of Pr3+, 880 and 1060 nm of Nd3+ as well as 978 nm of Yb3+, respectively. The energy transfer mechanism among Pr3+, Nd3+ and Yb3+ ions which was responsible for the observed ultra-broadband near-infrared emission was investigated to understand the luminescent phenomena. In addition, Judd-Ofelt theory was applied to predict the radiative properties of doped rare-earth ions, and some important radiative parameters such as radiative transition probability, branching ratio and radiative lifetime were derived. Meanwhile, the structural information of amorphous nature and vibrational units was revealed by the XRD pattern and Raman spectrum. Also, the DSC curve displayed the good thermal stability to resist thermal damage for studied tellurite glass with high glass transition temperature. The results indicate that Pr3+/Nd3+/Yb3+ tri-doped tellurite glass is a promising material for ultra-broadband fiber lasers operating around 1.0 μm near-infrared band.

Mode-Locked All-Fiber Laser Emitting Two-Color High-Order Transverse Mode

We demonstrate that the mode-locked all-fiber laser can simultaneously emit two-color broadband LP11 transverse mode in the near-infrared region by sharing a common mode-selective coupler (MSC). The MSC mode converter is designed to achieve simultaneous dual-channel mode conversion corresponding to the wavelength regions at 1.0 and $1.5~\mu \text{m}$ , in which each channel possesses broadband mode conversion from LP01 to LP11 mode with high mode purity. As a proof of concept, we implement an all-fiber ytterbium (Yb)- and erbium (Er)-doped fiber lasers with a mode-locked two-color LP11 modal output. The laser consists of two ring cavities combined with a common MSC mode converter. The generated LP11 modal pulses have a full width at half maximum of 11 and 8.1 nm for Yb- and Er-doped fiber laser, respectively. The presented fiber laser would represent a promising light source in the field of structured light and ultrafast optics.

Enhanced near IR downconversion luminescence in Eu3+-Yb3+ co-doped V activated ZnO host: An effort towards efficiency enhancement in Si-Solar cells

We report a new V activated ZnO host co-doped with Yb3+ and Eu3+ downconversion (DC) phosphor to convert the UV photons to near Infra-red (NIR) photons. The absorption efficiency of the ZnO host with activator Yb3+ is found to get significantly enhanced with V doping. The NIR emission at 980 nm of Yb3+ is enhanced at an optimal concentration of 3 mol% V in ZnO host (ZV). Further, with an additional sensitizer Eu3+, enhanced NIR emission is observed at 980 nm for the corresponding excitation of Eu3+. The mechanisms for the energy transfer from the host (ZV) and sensitizer (Eu3+) to the activator (Yb3+) are discussed in detail. This enables ZV:Eu3+,Yb3+ as an efficient DC phosphor which could enhance the spectral response of Si-solar cells in the UV range.

A novel solid-solution garnet Yb:YAG-MnASG with enhanced spectral properties

A novel solid-solution garnet Yb3+ doped Y3Al5O12Mn3Al2(SiO4)3 (Yb:YAG-MnASG) has been designed and grown for the first time. The polycrystalline materials, crystal growth, crystal structures, absorption and emission spectra, energy level schema, fluorescence lifetime and laser performance parameters were investigated in detail. Owing to the inhomogeneity in the local environment of Yb3+ caused by the cationic substitutions of Mn2+ for Y3+, Si4+ for Al3+ and high crystal-field strengths caused by distorted host sites, both of the absorption and emission spectral bandwidth of Yb:YAG-MnASG crystal are broadened compared with Yb:YAG. The maximal full width at half maximum (FWHM) of absorption spectra around 940 nm and emission spectra around 1030 nm for Yb:YAG-MnASG crystal are almost 1.2 and 2.5 times larger than those of Yb:YAG crystal, respectively. The results reveal that the novel solid-solution garnet Yb:YAG-MnASG is an excellent candidate for ultrafast pulse laser crystal.

Synthesis and luminescence properties of Yb-doped Y2O3, Sc2O3 and Lu2O3 solid solutions nanopowders

An approach of self-propagating high-temperature synthesis of ytterbium doped mixed yttria, scandia and lutetia powders Yb0.1(RE1xRE21-x)1.9O3 (RE1 and RE2 = Sc, Y, Lu, x = 0, 0.25, 0.5, 0.75, 1) was developed. A comparative study of the structural properties of the powders obtained by XRD analysis and Raman spectroscopy was carried out. The formation of rare earth oxides solid solutions throughout the studied compositional range was confirmed. The presence of residual hydroxyl groups in the resulting powders, most notable for scandia, was demonstrated. The broadening of Yb3+ ions luminescence bands in the matrices of structurally disordered mixed oxides was ascertained in comparison with individual rare earth oxides from 16 nm for Yb:Sc2O3 up to 25 nm for Yb0.1(Y0.75Sc0.25)1.9O3.

High-gain (43 dB), high-power (40 W), highly efficient multipass amplifier at 995 nm in Yb:LiYF4

A simple implementation of a multipass amplifier along with the use of a cryogenic Yb:LiYF4 (YLF) gain medium has enabled the demonstration of a bulk amplifier with an unprecedented combination of large-signal gain (43 dB), efficiency (>50% optical), average output power (40 W) and a near-diffraction-limited output beam.

Effect of power scale of 974 and 633 nm lasers on the induced loss at 633 nm of Yb3+/Al3+ co-doped silica fiber

Induced loss at 633 nm is tested in Yb3+/Al3+ co-doped silica fiber by a core pumped with a 974 nm laser and probed with a 633 nm laser. The fiber is prepared by the modified chemical vapor deposition method combined with solution doping. Different power scales of pump light and probe light are used in the tests. It is found that there is a dynamic equilibrium between photobleaching induced by 633 nm probe light and photodarkening (PD) induced by 974 nm pump light. For the first time to our knowledge, the effect of 633 nm probe laser power on an induced loss test of Yb3+/Al3+ co-doped silica fiber is studied quantitatively. It suggests that as long as the 633 nm probe light power is less than 0.2 mW, the induced loss is mainly contributed by the PD effect of pumping light, and the deviation of induced loss is less than 5%.

Production and Characterization of Tb3+/Yb3+ Co-Activated AlON Thin Films for Down Conversion Applications in Photovoltaic Cells

ABSTRACTTerbium and ytterbium co-doped aluminum oxynitride thin films were grown onto silicon substrates using radiofrequency magnetron sputtering. Aluminum oxynitride samples doped with 4.6 at. % of Yb3+ and co-doped with 0.4 at. % of Tb3+ were obtained. The prepared samples were annealed from 150°C to 850°C in steps of 100°C. By using energy dispersive X-ray analysis we measured the sample composition and the doping concentration. The emission intensities at different annealing temperatures were characterized using photoluminescence measurements upon excitation at 325 nm. The 5D4 → 7F5 main transition of Tb3+ and the characteristic near infrared emission at 980 nm of Yb3+ were recorded. In order to study the luminescence behavior of the samples in terms of a down conversion process, we have plotted the integrated areas of the main transition peaks versus the annealing temperature.

Luminescence and energy transfer progress in Bi-Yb co-doped germanate glass

The Bi-doped and Bi-Yb co-doped germanate glasses were fabricated by high temperature melting-quenched technique. The absorption spectra, near-infrared (NIR) luminescence properties and decay time spectra are investigated. The results show that the NIR emission peak around 1030 nm of Yb3+ ions and two NIR emission bands around 1180 and 1300 nm of Bi ions are observed, under 690 nm LD excitation. Two NIR emission bands of Bi-related are ascribing in different Bi-related NIR emission centers, Bi0 for 1180 nm and Bi+ ion for 1300 nm, respectively. NIR luminescence intensity of Yb3+ ions, Bi0 and Bi+ ion is decreased. The full width at half maximum (FWHM) is broadening with the increasing in Yb2O3 concentration, and over 361 nm. The energy transfer (ET) among Yb3+, Bi0, and Bi+ NIR emission center is also investigated, under 690 nm LD excitation. It shows that Bi0 ion transfer energy to Bi+ and Yb3+ ions. The Yb3+ ion addition is benefit to Bi+ ions NIR luminescence. This could be the reason for broadening the FWHM. Yb–Bi codoped germanate glass is a promising material for broadband optical amplification.

Activation and deactivation effects to Ho^3+ at ~28 μm MIR emission by Yb^3+ and Pr^3+ ions in YAG crystal

The use of Yb3+ and Pr3+ co-doping with Ho3+ to enhance the Ho3+:5I6→5I7 ~2.8μm emissions are investigated in the YAG crystal for the first time. Absorption spectra of the Yb:Ho:YAG and Yb:Ho:Pr:YAG crystals find that doping of Yb3+ increase absorption intensity within 850-1050nm and make the crystals suitable to high-power InGaAs LDs. Fluorescence spectra show that ~2.8μm lasers may be realized on both crystals at different wavelengths, with the maximum emission cross section of 1.69 × 10−20 cm2 at 2780 nm for Yb:Ho:Pr:YAG and 1.23 × 10−20 cm2 at 2848 nm for Yb:Ho:YAG. Lifetime results and energy transfer analyses indicate that activator Yb3+ ions can prolong the higher laser level of Ho3+: 5I6 and deactivator Pr3+ ions are able to depopulate the lower laser level of Ho3+: 5I7, both beneficial to population inversion and contributed to facilitate ~2.8μm laser operations. All these results indicate that Yb:Ho:Pr:YAG crystal is a promising laser medium for LD-pumped ~2.8μm laser applications.