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- 摘要
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- 实验方案
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Effective Upconverter and Light Scattering Dual Function LiYF <sub/>4</sub> :Er <sup>3+</sup> /Yb <sup>3+</sup> Assisted Photoelectrode for High Performance Cosensitized Dye Sensitized Solar Cells
摘要： Conversion of near-infrared (NIR) light photons into visible light has remarkable advantages in dye sensitized solar cells (DSSCs) for their improved performance. This study uncovers the dual function of LiYF4:Er3+/Yb3+ as upconverter (UC) and light scattering material in DSSCs by its incorporation onto the photoelectrode. The LiYF4:Er3+/Yb3+ powders were prepared using a facile hydrothermal process followed by spin deposition of LiYF4:Er3+/Yb3+ suspensions over photoelectrode. The photoelectrode used for this investigation was further cosensitized with N719 and squaraine SPSQ2 dyes. The dual functions of LiYF4:Er3+/Yb3+ material coupled with dye cosensitization treatment produced record power conversion efficiency (PCE) of 10.53% in the fabricated DSSC. The LiYF4:Er3+/Yb3+ enabled the photoelectrode DSSC to exhibit good short-circuit current density (Jsc) of 22.16 mA/cm2, open-circuit voltage (Voc) of 0.66 V, and fill factor (FF) of 0.72. This work is the debut attempt toward the application of a photoelectrode embedded with dual function and cosensitized materials to utilize lower energetic photons through the upconversion mechanism and improve absorption close to red wavelengths (absorption band 630?700 nm) through the dye cosensitization process.
关键词： DSSC,LiYF4:Er3+/Yb3+,squaraine dye,cosensitization,high performing,dual function upconverter
更新于2025-09-23 15:19:57
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Inverted pyramid Er3+ and Yb3+ Co-doped TiO2 nanorod arrays based perovskite solar cell: Infrared response and improved current density
摘要： In this study, a Yb3+, Er3+ co-doped TiO2 inverted pyramid nanorod (NR) array and a compact TiO2 ?lm are simultaneously fabricated as the mesoporous support layer and electron-blocking layer, respectively, by a one-pot hydrothermal method. The scanning electron microscopy results show that the incorporation of Er3+ and Yb3+ causes changes not only in the growth rate of the NRs, but also in the TiO2 NR morphology. The Er3+, Yb3+ co-doped TiO2 NRs exhibit an inverted pyramidal morphology, which is bene?cial for perovskite permeation and light utilization. Notably, the Er3+, Yb3+ co-doping causes changes in the band gap of TiO2 and leads to 25% increase in the current density. The electrochemical impedance spectroscopy results show that the device based on the doped TiO2 NRs has a higher recombination resistance and a lower transfer resistance than those of the undoped device, and thereby, the doped device exhibits a lower electron recombination rate. In addition, the upconversion Er and Yb co-doped device exhibits 25% higher current density and 17% higher photon-to-electron conversion e?ciency, as revealed by the J-V test results. Moreover, the optimized e?ciency of the TiO2 NR array-based perovskite solar cell is determined to be 10.02%. Furthermore, the Er and Yb co-doped device exhibits a near-infrared response, an e?ciency of 0.1% is achieved under infrared light (800–1100 nm) irradiation. This upconversion material can widen the photovoltaic responses of solar cells into the near-infrared region and improve the utilization of sunlight.
关键词： Infrared response,Yb3+,Er3+ co-doped,TiO2 nanorods,Perovskite solar cell
更新于2025-09-23 15:19:57
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Er3+,Yb3+-doped oxyfluorotellurite glassesa??Impact of temperature on spectroscopic properties and optical sensor qualities
摘要： Oxyfluorotellurite glasses co-doped with erbium (0.5%) and ytterbium (2%, 5%) were manufactured from high purity reagents at 840 °C in air. Differential thermal analysis was used to estimate the temperatures of glass transition and glass crystallization of 2% and 5%Yb co-doped glasses. The effect of Yb3+ co-doping on relaxation dynamics of erbium excited states was demonstrated by the means of excitation, emission and fluorescence lifetime spectroscopy. Up-conversion luminescence spectra were studied in a function of temperature in the 295–675 K range, yielding information on thermal quenching of the emission and a temperature sensing model based on 2H11/2–4I15/2 to 4S3/2–4I15/2 erbium fluorescence intensity ratio. Application potential of the investigated material in optical sensor thermometry was evaluated. Maximum absolute and relative sensitivities were established at 6.45 × 10?3 K?1 at T = 675 K and 0.46 %K?1 at T = 400 K, respectively.
关键词： Oxyfluorotellurite glass,(Er3+,Yb3+) Upconversion,Temperature sensor
更新于2025-09-23 15:19:57
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Near-infrared and upconversion luminescence of Tm3+ and Tm3+/Yb3+-doped oxyfluorosilicate glasses
摘要： Oxyfluorosilicate glasses-doped with different concentrations of Tm3+ and Tm3+/Yb3+ ions have been synthesized and characterized their absorption, photoluminescence, luminescence decay and upconversion properties. The Judd-Ofelt intensity parameters have been obtained from the absorption spectrum of Tm3+ single-doped glass and are in turn used to calculate radiative properties such as transition probabilities, branching ratios and lifetimes for the fluorescent levels of Tm3+ ions. Visible and near-infrared emission spectra of Tm3+ and Tm3+/Yb3+-doped glasses have been measured under 473 nm laser excitation. The quenching of emission intensities at higher concentrations of Tm3+ ions has been found to be due to cross-relaxation mechanisms. The Tm3+/Yb3+ co-doped glasses show upconverted emissions under 975 nm laser excitation. The mechanism of upconversion has been explained based on the pump power dependence of upconversion luminescence. The results reveal that the co-doped glasses are promising for optical fiber amplifiers operating at the relatively low-loss wavelength regions.
关键词： Glasses,Optical properties,1.2 μm emission,Upconversion,Judd-Ofelt theory,Tm3+ and Tm3+/Yb3+
更新于2025-09-19 17:15:36
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Enhanced UV-Vis-NIR activated photocatalytic activity from Fe <sup>3+</sup> -doped BiOBr:Yb <sup>3+</sup> /Er <sup>3+</sup> upconversion nanoplates: synergistic effect and mechanism insight
摘要： Upconversion (UC) materials are recognized as promising candidates to harvest solar energy for photocatalysis. In this work, a simple strategy for simultaneously enhancing the UC luminescence and photocatalytic efficiency of BiOBr:Yb3+/Er3+ nanoplates through Fe3+ ion doping is reported. Compared to the Fe3+-free sample, the UC emission intensity was significantly enhanced through tailoring of the crystal symmetry by Fe3+ ions. Experiment and DFT calculations reveal that the introduction of Fe3+ ions resulted in the formation of an impurity energy level, extending to the light absorption region. As expected, the Fe3+-doped BiOBr:Yb3+/Er3+ nanoplates exhibit a wide photoresponse from the UV to NIR regions, good stability, and obviously enhanced photocatalytic activities compared with the BiOBr:Yb3+/Er3+ nanoplates in the degradation of RhB. The boosted photocatalytic activity can be attributed to the synergic effect of the efficient utilization of UC luminescence and Fe3+ doping, where Fe3+ doping could improve the light harvesting capacity, enhance the separation efficiency of electron and hole (e?/h+) pairs, and promote the production of highly oxidative species. This work not only provides a promising system for the efficient utilization of solar light, but also offers a feasible guideline for the further design of broad-spectrum active photocatalysts.
关键词： Enhanced UV-Vis-NIR activated photocatalytic activity,mechanism insight,Fe3+-doped BiOBr:Yb3+/Er3+ upconversion nanoplates,synergistic effect
更新于2025-09-19 17:15:36
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Effect of Bi <sup>3+</sup> ion on upconversion-based induced optical heating and temperature sensing characteristics in the Er <sup>3+</sup> /Yb <sup>3+</sup> co-doped La <sub/>2</sub> O <sub/>3</sub> nano-phosphor
摘要： The upconversion-based optical heating and temperature sensing characteristics are investigated in the Er3+/Yb3+/Bi3+ tri-doped La2O3 nano-phosphor synthesized through a solution combustion method. The structural measurements reveal an increase in lattice parameters and particles size of the phosphor on increasing the concentrations of Bi3+ ions. The energy dispersive spectroscopic (EDS) measurements confirm the presence of La, Er, Yb, Bi and O elements in the tri-doped phosphor. The absorption spectra show the large number of bands due to Er3+, Yb3+ and Bi3+ ions. The Er3+/Yb3+ co-doped phosphor gives strong green emission bands at 523 and 548 nm upon 976 nm excitation due to 2H11/2 / 4I15/2 and 4S3/2 / 4I15/2 transitions of Er3+ ion, respectively. The emission intensity of these bands is enhanced upto 15 times in the presence of Bi3+ ions. The emission intensities of the 523 and 548 nm bands vary non-linearly with the pump power. The fluorescence intensity ratio (FIR) of the thermally coupled 523 and 548 nm emission bands shows efficient optical heating in the tri-doped phosphor. The FIR of the 523 and 548 nm emission bands further varies with the increase in temperature of the phosphor. The relative temperature sensing sensitivity has been calculated to be 71 × 10?4 K?1 at 450 K for the tri-doped phosphor. Thus, the Er3+/Yb3+/Bi3+ tri-doped La2O3 nano-phosphor may provide a platform to use it in the photonic devices, as an optical heater and temperature sensor.
关键词： La2O3 nano-phosphor,temperature sensing,optical heating,solution combustion method,Er3+/Yb3+/Bi3+ tri-doped,upconversion
更新于2025-09-19 17:15:36
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Spectroscopic and Structural Properties of Yb <sup>3+</sup> -Doped and Undoped 2D-Mos <sub/>2</sub> Thin Films for Optoelectronic and Photonic Device Applications
摘要： Molybdenum disulphide (MoS2) has layered structure and is classed as a transition metal-disulphide (TMD) material. Recently it has drawn significant attention for exploring optoelectronic and photonic properties on sub-nanometre scale, with a potential for accessing quantum interactions [1]. The electronic structure and stoichiometry of TMDs make them distinguishable from the metallic graphene, as the TMDs depict a clear bandgap, as in compound semiconductors [2], which is quite attractive for device engineering and applications in photovoltaic, energy storage, and bandgap engineered light-sources [3]. In this research, the fabrication of undoped and Yb3+-ion doped MoS2 nanometre (nm)-scale thin films are discussed using femto-second pulsed laser deposition (fs-PLD) and the structural and spectroscopic properties of fs-PLD are compared with liquid-phase epitaxy grown undoped MoS2 films. Such a comparative analysis may offer materials fabrication platform in future for engineering optoelectronic and photonic devices on silica glass and silicon platforms.
关键词： DFT,Raman spectroscopy,nonlinear optical properties,Molybdenum disulphide,fs-PLD,photonic devices,Yb3+-doped,optoelectronic,thin films
更新于2025-09-19 17:13:59
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Upconverting TiO <sub/>2</sub> spheres with light scattering effect for enhanced quantum dot-sensitized solar cells
摘要： Semiconductor quantum dots (QDs) for solar cells could only absorb solar light in the visible region. Upconverters could convert near-infrared (NIR) photons into visible light photons that could be used to generate photocurrent by the sensitizers. Consequently, it is reasonable to utilize upconverters in the quantum dot-sensitized solar cells (QDSCs) in order to broaden the light utilization region. In this article, Yb3+/Er3+ co-doped TiO2 spheres were integrated into the photoanodes for QDSCs. The influence of photoanode configuration on the performance of the QDSCs has been scrutinized. The photoanode with the optimized composite film was employed to fabricate QDSC, yielding a conversion efficiency (η) of 3.53%. The QDSC with the composite film photoanode outperforms that with the pure TiO2 film photoanode. The amplified cell performance for the composite photoanodes could be attributed to the following two aspects: first, the upconversion process of the upconverter leads to indirect exploitation of NIR light. Second, the light scattering effect of the upconverter-doped TiO2 spheres enhances the absorption of visible light.
关键词： Quantum Dot-Sensitized Solar Cells,Yb3+/Er3+ Co-Doped TiO2,Upconversion,Light Scattering Effect
更新于2025-09-19 17:13:59
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Laser induced thermochromism and reversible upconversion emission modulation of a novel WO3:Yb3+,Er3+ ceramic: dual-modal fingerprint acquisition application
摘要： The quick and accurate identity recognition can be obtained by the acquisition of fingerprints in the financial, telecommunication, transportation, education and medical fields. However, conventional fingerprint acquisition technologies have many problems such as the high background interference, low detection sensitivity and complicated operation. In this work, the reversible modulation of laser induced thermochromism and upconversion luminescence of a novel WO3:Yb3+,Er3+ ceramic was achieved even after several cycles, exhibiting excellent repeatability. For the first time, we realized the dual-modal fingerprint acquisition by means of the laser induced thermochromism and upconversion luminescence of WO3:Yb3+,Er3+ ceramic. Particularly, this method shows ultrahigh stability, preserving the fingerprint patterns as long as one year. The results demonstrated that our technology is nondestructive, repeatable, highly effective and stable, paving the way for the development of the acquisition and storage of fingerprints.
关键词： Photo-thermal-chromism,Upconversion luminescence,WO3:Yb3+,Er3+ ceramics,Fingerprint acquisition
更新于2025-09-19 17:13:59
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Highly sensitive optical thermometers based on unconventional thermometric coupled levels of Tm <sup>3+</sup> following a Boltzmann-type distribution in oxyfluoride glass ceramics
摘要： Oxyfluoride glass ceramics (GCs) containing b-PbF2 nanocrystals (NCs) doped with Tm3+ and Yb3+ were synthesized by a conventional melt-quenching method and a subsequent glass crystallization route. In b-PbF2:Tm3+/Yb3+ GCs, Tm3+/Yb3+ is surrounded by fluoride with a low phonon energy, ensuring its intense emissions at 362 (1D2 - 3H6), 450 (1D2 - 3F4), 478 (1G4 - 3H6), 648 (1G4 - 3F4), 700 (3F2,3 - 3H6) and 800 (3H4 - 3H6) nm excited by 976 nm laser. Furthermore, temperature-dependent upconversion luminescence (UCL) behaviors of b-PbF2:Tm3+/Yb3+ GCs were systematically investigated to explore the thermometric performance with the assistance of the fluorescence intensity ratio (FIR) method by employing conventional TCELs of 3F2,3/3H4 following a Boltzmann distribution and two unconventional coupled levels of 3F2,3/1D2 and 3F2,3/1G4 governed by a Boltzmann-type distribution. Impressively, the relative sensitivity (Sr) of 3F2,3/1D2 states (I700nm/I362nm), 3F2,3/1G4 states (I700nm/I478nm), and 3F2,3/3H4 states (I700nm/I800nm) was obtained in this work as values of 1.30% K-1, 1.38% K-1, and 0.87% K-1, respectively. Compared with the conventional TCELs of 3F2,3/3H4, the two unconventional coupled levels of 3F2,3/1D2 and 3F2,3/1G4 present preferable properties as temperature probes enabling optical ratiometric thermometers. The research in this work provides an important advance in exploring other innovative FIR methods for optical thermometers to enable an intense and precise probing signal and detect temperature accurately.
关键词： fluorescence intensity ratio,Yb3+,oxyfluoride glass ceramics,Tm3+,Boltzmann-type distribution,optical thermometers
更新于2025-09-16 10:30:52