Ytterbium Emission Research Articles

Anomalous emission of Yb2+ in CaF2:Tb3+, Yb3+ up-conversion phosphor

Anomalous emission of ytterbium (Yb2+) was observed in terbium (Tb3+)-Yb co-doped CaF2 up-conversion nanophosphor. The anomalous emission of Yb2+ is a phenomenon observed, where the Yb2+ ion emits light with a longer wavelength than expected. This phenomenon has attracted significant attention due to its potential applications in a range of fields, including optical communication, sensing and imaging. In this study the presence of Yb2+ ions was confirmed by X-ray photoelectron spectroscopy. The existence of the anomalous emission of Yb2+ in CaF2:Tb3+-Yb significantly influenced the blue emission of the Tb3+ ions due to the up-conversion process. The addition of lithium ions as charge compensators into the system decreased the anomalous emission of the Yb2+ ions. Therefore, understanding the mechanism of this anomalous emission of Yb2+ ions in CaF2:Tb3+-Yb and other materials with enhanced emission properties could have significant technological applications.

Thermosensitive Tm3+/Yb3+ co-doped oxyfluorotellurite glasses – spectroscopic and temperature sensor properties

Oxyfluorotellurite (65-x)TeO2–20ZnF2–12PbO–3Nb2O5–xTm2O3 (x = 0.5, 2 and 5) and (65-x-y)TeO2–20ZnF2–12PbO–3Nb2O5–xTm2O3–yYb2O3 (x = 0.5, y = 2 and x = 0.5, y = 5) glass systems were manufactured. Glass thermal stability was examined by means of differential thermal analysis (DTA) and some thermal stability criteria ΔT, H’ and S were determined. Absorption spectrum was utilized to prepare Judd-Ofelt (J-O) calculations and consequently oscillator strengths, intensity parameters Ω2,4,6, radiative transition probabilities, branching ratios and radiative lifetimes of luminescent levels were estimated. Emission spectra and luminescence decay curves were measured as a function of temperature in the 300–625 K range. Based on the upconversion luminescence of Tm3+ the optical temperature sensor qualities have been evaluated for Tm3+/Yb3+ co-doped sample. The fluorescence intensity ratio (FIR) between transitions 700 nm (Tm3+:3F2,3 → 3H6)/800 nm (Tm3+:3H4 → 3H6) for 975 nm excitation and 700 nm (Tm3+:3F2,3 → 3H6)/470 nm (Tm3+:1G4 → 3H6) for 803 nm excitation were determined and an adequate relative thermal sensitivity S was estimated. The significant value of relative thermal sensitivity 1.12 %K−1 was determined when NIR Yb3+ and Tm3+ emission bands were analyzed, however. Effective emission cross section was calculated for 3F4 → 3H6 potential laser transition of thulium around 1.9 μm in single-doped Tm3+ glass. Furthermore, effect of temperature on down-converted and up-converted thulium and ytterbium emission and on relaxation dynamic of involved excited states was studied in details.

A conjugated porphyrin as a red-light sensitizer for near-infrared emission of ytterbium(iii) ion

A conjugated porphyrin with broader absorption in the visible region was synthesized for sensitizing the near-infrared emission of ytterbium(iii) ions.

Impact of Host Composition, Codoping, or Tridoping on Quantum-Cutting Emission of Ytterbium in Halide Perovskite Quantum Dots and Solar Cell Applications.

Recently, various lanthanide ions (Ln3+) have been successfully doped into perovskite quantum dots (PQDs), and the quantum-cutting emission of 2F5/2-2F7/2 for Yb3+with a measurable inner efficiency of more than 100% has been discovered and applied as the luminescent converter of solar cells, which has opened a new branch for the application of PQDs. In this work, to further improve the quantum-cutting efficiency of Yb3+, the codoping and tridoping methods were used to improve the quantum-cutting emission of PQDs. The Yb3+-Ln3+ (Ln = Nd, Dy, Tb, Pr, Ce) pair-doped CsPbClxBryI3-x-y PQDs were fabricated, with all displaying excitonic emission, narrow-band emission of Ln3+ ions, and quantum-cutting emission of Yb3+ ions. It was interesting that Yb3+-Pr3+ as well as Yb3+-Ce3+ pairs could effectively sensitize the emission of Yb3+, owing to Pr3+ and Ce3+ ions offering intermediate energy states close to the exciton transition energy of the PQDs. After host composition optimization and tridoping investigation, overall emissions with a 173% photoluminescence quantum yield (PLQY) were obtained in the Yb3+-Pr3+-Ce3+-tridoped CsPbClBr2 PQDs. Then, the tridoped PQDs were designed as the down-converter for CuIn1-xGaxSe2 (CIGS) as well as the silicon solar cells, which leads to an enhancement of the power conversion efficiency (PCE) of as high as ∼20%. The modified CIGS was further employed to charge the smart mobile phone, which could largely shorten the charging time from 180 to 150 min. This finding is of great significant for expanding the application fields of the impurity-doped PQDs.

BODIPY-functionalized 1,10-phenanthroline as a long wavelength sensitizer for near-infrared emission of the ytterbium(iii) ion.

Two BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) moieties were chemically appended to the 4,7-positions of 1,10-phenanhtroline resulting in two new ligands (BODIPY-Phen and 4I-BODIPY-Phen) with strong absorption at 507 nm and 540 nm, respectively. BODIPY-Phen emits fluorescence strongly centered at 507 nm, whereas the fluorescence of 4I-BODIPY-Phen was completely quenched due to the introduction of four I atoms at its 2,6 positions. The two ligands reacted readily with tris(1,1,1,5,5,5-hexafluoro-2,4-pentanedionate) ytterbium(iii) dihydrate through substitution reactions forming eight-coordinate complexes that emit strongly at 976 nm upon excitation at their absorption maximal positions. Both complexes exhibited a lifetime of ∼11 μs in dichloromethane at room temperature.

High Nd3+→Yb3+ energy transfer efficiency in tungsten‐tellurite glass: A promising converter for solar cells

AbstractThis work reports on the energy transfer efficiency for Nd3+/Yb3+ co‐doped tellurite glasses (80TO2‐20WO3, in mol%,). The correlation between Yb3+ ion concentration and the downconversion mechanism was investigated using optical and thermal lens spectroscopies, which enabled investigation of the radiative and nonradiative processes, respectively, involved in energy transfer from neodymium to ytterbium. The Nd3+ near‐infrared fluorescence disappeared almost entirely when the maximum concentration of Yb3+ ions (4 mol%) was doped into the host. In contrast, there was a corresponding increase in the ytterbium emission at around 980 nm. When ytterbium was added, there was also a simultaneous reduction in the amount of heat generated by the sample due to a reduction in the nonradiative decay rate, corroborating the suspected high energy transfer efficiency of Nd3+→Yb3+. The results indicate that tungsten‐tellurite glasses may be of potential use in solar cells for matching the solar emission spectrum to the semiconductor cell.

X-ray Excitation Triggers Ytterbium Anomalous Emission in CaF2:Yb but Not in SrF2:Yb.

Materials that luminesce after excitation with ionizing radiation are extensively applied in physics, medicine, security, and industry. Lanthanide dopants are known to trigger crystal scintillation through their fast d-f emissions; the same is true for other important applications as lasers or phosphors for lighting. However, this ability can be seriously compromised by unwanted anomalous emissions often found with the most common lanthanide activators. We report high-resolution X-ray-excited optical (IR to UV) luminescence spectra of CaF2:Yb and SrF2:Yb samples excited at 8949 eV and 80 K. Ionizing radiation excites the known anomalous emission of ytterbium in the CaF2 host but not in the SrF2 host. Wave function-based ab initio calculations of host-to-dopant electron transfer and Yb2+/Yb3+ intervalence charge transfer explain the difference. The model also explains the lack of anomalous emission in Yb-doped SrF2 excited by VUV radiation.

Correction: Sisters together: co-sensitization of near-infrared emission of ytterbium(iii) by BODIPY and porphyrin dyes

Correction for 'Sisters together: co-sensitization of near-infrared emission of ytterbium(iii) by BODIPY and porphyrin dyes' by Hongshan He et al., Chem. Commun., 2017, 53, 10120-10123.

Sisters together: co-sensitization of near-infrared emission of ytterbium(iii) by BODIPY and porphyrin dyes.

A ytterbium(iii) acetate complex with a BODIPY and a porphyrin as co-sensitizers emits strongly at 978 nm over a broader excitation window between 450-560 nm.

On observation of the downconversion mechanism in Er3+/Yb3+ co-doped tellurite glass using thermal and optical parameters

In this work we report the observed downconversion (DC) mechanism in Er3+/Yb3+-codoped tellurite glasses (in mol%, 80TeO2–10Li2O–10TiO2). The samples were synthesized by the conventional melt-quenching method and then studied using optical spectroscopy and thermal lens spectroscopy (TLS). These characterizations enabled investigation of the radiative and nonradiative processes involved in energy transfer from erbium to ytterbium. The visible Er3+ fluorescence intensities decreased as a function of the Yb3+ concentration, and there was a corresponding increase in the ytterbium emission at around 980nm. Simultaneously, there was a reduction in the heat-generated due nonradiative decays (~21%) when ytterbium was added. This temperature change was measured by TLS measurements and the results corroborate with the indicated by spectroscopic interpretation.

Luminescence of ytterbium in CaS and SrS

CaS and SrS, in particular when doped with divalent europium and/or trivalent cerium, have been extensively studied as phosphor materials. In contrast, surprisingly little is known on the behavior of divalent Yb in both hosts. Therefore we report on the luminescence of divalent ytterbium in calcium sulfide and strontium sulfide. In CaS, an emission peak at 760nm is found, while in SrS ytterbium emission peaks at a strongly red-shifted 950nm are found. It is motivated that the former is typical for the common 5d–4f luminescence, while the latter is typical for anomalous divalent ytterbium luminescence. Depending on the excitation wavelength, trivalent ytterbium luminescence can also be observed in both hosts.

Iodized BODIPY as a long wavelength light sensitizer for the near-infrared emission of ytterbium(iii) ion

Novel 8-HOQ-BODIPY-3I was developed as an efficient sensitizer for the near-infrared emission of ytterbium(III) ion at 980 nm under long wavelength excitation.

PLD-grown Yb-doped Sesquioxide Films on Sapphire and Quartz Substrates

This paper focuses on the fabrication and characterization of crystalline Yb-doped sesquioxide films (Yb2O3, Yb:Lu2O3, Yb:Sc2O3) grown by pulsed laser deposition on single crystal sapphire (α-Al2O3) and quartz (α-SiO2) substrates as well as on lutetia (Lu2O3) and scandia (Sc2O3) substrates. Such ytterbium doped active films can be promising for use in a thin-disk laser setup. X-Ray diffraction measurements show that the films grow highly textured along <111> direction. The ω-scan (rocking curve) shows deviation of the crystallite orientation ∼4° in case of Lu2O3 and Yb2O3 films and <1° for Sc2O3 films. Yb2O3 films reveal no luminescence at room temperature and the well known Yb3+ emission in the 975-980 nm region (zero-phonon line) can only be observed at temperatures below 20 K. A similar effect is observed in a bulk Yb2O3 crystal. Ytterbium emission and excitation spectra measured at room temperature for Yb(5%):Lu2O3 and Yb(4%):Sc2O3 films resemble those of the bulk crystal very closely. Luminescence decay lifetimes are also comparable to those measured in a bulk crystal. This indicates a high quantum efficiency of the Yb3+-emission and allows application of such films as active media for thin disk lasers.

Laser heated pedestal growth and optical properties of Yb 3+-doped LiNbO 3 single crystal fibers

The elaboration of Yb 3+-doped LiNbO 3:Sc 3+ and LiNbO 3:Mg 2+ single crystal fibers by the laser heated pedestal growth technique is reported. The ytterbium emission and absorption cross-sections are given. We show that it is possible to obtain the coincidence between the wavelength of phase-matching for second harmonic generation and the wavelength of laser emission by varying the host composition, in order to achieve a self-doubling laser material.

Cathodoluminescence of ytterbium-implanted zinc telluride

Abstract The cathodoluminescence emission of Yb3+ ions in zinc telluride produced by implantation of ytterbium ions in samples of differing degrees of non-stoichiometry has been studied as a function of implantation and annealing parameters. Successful implantation of ytterbium in zinc telluride was found to be strongly dependent on the non-stoichiometry present in the lattice. Because the ytterbium ions can occupy interstitial sites or zinc substitutional sites the relative intensities of emission lines in the characteristic ytterbium spectrum (980–1100 nm) can be changed by controlling the annealing treatment in the temperature range 250°–500°C. Annealing at higher temperatures was found to reduce the total ytterbium emission intensity. To produce the most intense, well-structured ytterbium emission lines it is essential to implant tellurium rich material at as low a temperature as possible.