- 标题
- 摘要
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- 实验方案
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Quantum cutting properties of Tb3+/Yb3+ co-doped ZrO2-SiO2 nano-crystalized glasses synthesized via a sol-gel route
摘要： Tb3+/Yb3+ co-doped ZrO2-SiO2 nano-crystallized glasses were prepared by a sol-gel process. The crystal structure and optical properties including down-conversion photoluminescence (or, quantum cutting) of the Tb3+-Yb3+ system with respect to gel heat treatment temperature were investigated by X-ray diffraction (XRD), Raman, photoluminescence (PL), and PL decay curves analysis. The energy transfer efficiency from Tb3+ to Yb3+ ions, which converts one photon to two photons with lower energy, increased with heat-treatment temperature. Furthermore, the oxidation state of Tb4+ ions was suspected to influence the emission intensity of Tb3+ and energy conversion efficiency. Thus, a post-treatment reduction was applied to the sample heated at 1100 oC by annealing it at 1100 oC for 1 h under 5%H2/95%N2 reductive atmosphere. Consequently, the thermodynamically generated Tb4+ ions were reduced to a trivalent state, leading to higher energy transfer efficiency.
关键词： ZrO2 nanocrystals,Sol-gel method,photoluminescence,quantum cutting,Tb3+-Yb3+ pair,Tb4+ ions
更新于2025-09-09 09:28:46
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On the efficient Te4+→Yb3+ cooperative energy transfer mechanism in tellurite glasses: A potential material for luminescent solar concentrators
摘要： Te4+/Yb3+ co-doped 80%TeO2-20%Li2O glasses (amounts in mol%) were prepared by the conventional melt-quenching method in an ambient atmosphere, in order to investigate their optical characteristics for application in solar cells. An efficient near-infrared down-conversion mechanism was observed in these samples, involving the emission of two near infrared photons (at around 978 nm) after the absorption of one photon in the ultraviolet-blue region. This effect occurred by means of a process of cooperative energy transfer (CET) from Te4+ to Yb3+ ions. The CET efficiency (h CET) was calculated from radiative transitions (lifetime) and also by a new method, developed in this work, based on rate equations quantifying the non-radiative transitions (thermal effect) involved in the system. The two methods showed very good agreement, with h CET between 82-100% obtained for the sample prepared using a higher Yb3+ concentration (4 mol%). The results suggested that these tellurite materials could have potential applications in improving the efficiency of silicon-based solar cells.
关键词： Te4+ ions,Thermal lens effect,Tellurite glass,Yb3+ ions,Down-conversion,Cooperative energy transfer
更新于2025-09-09 09:28:46
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Er3+-to-Yb3+ and Pr3+-to-Yb3+ energy transfer for highly efficient near-infrared cryogenic optical temperature sensing
摘要： Here, the very high thermal sensing capability of Er3+,Yb3+ doped LaF3 nanoparticles, where Er3+-to-Yb3+ energy transfer is used, are reported. Also Pr3+,Yb3+ doped LaF3 nanoparticles, with Pr3+-to-Yb3+ energy transfer, showed temperature sensing in the same temperature regime, but with lower performance. The investigated Er3+,Yb3+ doped LaF3 nanoparticles show a remarkably high relative sensitivity Sr up to 6.6092 %K-1 (at 15K) in the near-infrared (NIR), in the cryogenic (15 – 105K) temperature region opening a whole new thermometric system suitable for advanced applications in the very low temperature ranges. Up to date reports on NIR cryogenic sensors are very scarce.
关键词： near-infrared,Pr3+-to-Yb3+ energy transfer,Er3+-to-Yb3+ energy transfer,LaF3 nanoparticles,cryogenic temperature sensing
更新于2025-09-04 15:30:14
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Using NMR Relaxometry to Probe Yb <sup>3+</sup> – Er <sup>3+</sup> Interactions in Highly Doped Nanocrystalline NaYF <sub/>4</sub> Nanostructures
摘要： Solid–state nuclear magnetic resonance (NMR) spectroscopy is used to study heavily Yb3+ and Er3+ doped, fluorescent NaY1–x–yYbxEryF4 nanoparticles. An understanding of the 19F wide line NMR response suggests that the 0 ppm portion of the 19F NMR spectrum can be used as a probe of trivalent lanthanide content via spin lattice relaxation time changes. A Yb3+ and Er3+ magnetic interaction is manifest as a cooperative contribution to the 19F spin lattice relaxation rate in heavily co–doped nanoparticle samples. The results from this study will help understand the mechanism of enhanced optical up–conversion among these well–known nanostructures.
关键词： Solid–State NMR,Yb3+ – Er3+ Interactions,Nanocrystalline NaYF4,Optical Up–Conversion,NMR Relaxometry
更新于2025-09-04 15:30:14
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Microstructure and Optical Properties of SPION/Sr3V2O8:Er3+, Yb3+ Nanocomposites Synthesized by Microwave-Assisted Metathetic Method
摘要： The nanocomposites of Er3+/Yb3+ co-doped Sr3V2O8 (Sr3V2O8:Er3+/Yb3+) with superparamagnetic iron oxide nanoparticles (SPIONs) have been successfully synthesized by a microwave-assisted metasthetic method followed by heat-treatment. The microstructure exhibited well-defined and homogeneous morphology with the Sr3V2O8:Er3+/Yb3+ particle size of 1-2 μm and Fe3O4 particle size of 100-500 nm. The Fe3O4 nonoparticles were self-preferentially crystallized and immobilized on the surface of Sr3V2O8:Er3+/Yb3+ particles. The synthesized SPION/Sr3V2O8:Er3+/Yb3+ nanocomposites were characterized by X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Other optical properties were also examined using photoluminescence emission measurements and Raman spectroscopy.
关键词： Microwave-assisted metathetic method,Nanocomposites,Microstructure,Optical properties,SPION/Sr3V2O8:Er3+/Yb3+
更新于2025-09-04 15:30:14