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《自然科学进展(英文版)》2019,29(5):549-555
Yb~(3+)/Ln~(3+)(Ln=Er/Tm/Ho)-α-sialon ceramics were fabricated by hot press sintering technique.Their microstructure and luminescent properties were studied by XRD,EDS,HRTEM and photoluminescence measurements.The results showed that the sintered ceramics consisted ofα-Sialon with a trace amount ofβ-Sialon phase.The frequency upconversion and downconversion properties of Yb~(3+)/Ln~(3+)(Ln=Er/Tm/Ho)-α-Sialon ceramics were investigated under 980 nm low-power excitation.The different concentrations of Yb~(3+)/Ln~(3+)(Ln=Er/Tm/Ho)produced multicolor emissions characteristics of each Ln~(3+)ion as a result of the energy transfer from Yb~(3+)to Er~(3+),Tm~(3+)and Ho~(3+)ions.The EDS spectra measurements and mappings showed that the Ln~(3+)ions were well incorporated in theα-Sialon matrix.Temporal evolution of the emission decay behavior has been investigated to understand the energy transfer mechanism. 相似文献
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《自然科学进展(英文版)》2021,31(6):891-897
This paper reports the first demonstration of super broadband infrared downshifting emission extending from 1640 nm to 2200 nm with the full width at half maximum of ∼ 417 nm in lanthanides (Er3+, Ho3+, and Tm3+)-doped α-SiAlON ceramics upon 793 nm excitation. Using α-Si3N4 ceramic as a precursor the lanthanides-doped α-SiAlON ceramics were synthesized by the hot-press method. The lanthanides induced no significant secondary phases in the sintered α-SiAlON ceramics. Strong two-photon upconversion emission bands centered at 547, 671 and 694 nm have also been observed upon 793 nm excitation. The time-resolved measurements of the upconversion emissions confirm that the efficient energy transfer among the Er3+, Ho3+ and Tm3+ ions as well as the ground state absorption in Er3+ and Tm3+ are responsible for the observed spectroscopic properties. 相似文献
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将Er2O3和Yb2O3掺杂杂到SiO2和PbF2混合物中,烧结后,制成约2mm厚的薄片样品,为了便于比较而获得最佳的Yb^3离子浓度使上转换荧光峰强度最强,各样品中SiO2,PbF2和Er2O3的摩尔百分比是固定的,Yb2O3的浓度分别使用了0.6mol%,1.4mol%,2.40mol%,4.66mol%和8.0mol,在930nmLED激发下,测量了这五种样品的荧光光谱,观察到上转换谱线主要有绿光(约528nm,540nm,547nm和550nm),红光(约652nm,665nm和668nm),蓝光(约487nm和493nm),紫光(约412nm)和近红外光(约802nm,845nm,852nm),发现对于以上五种Yb2O3浓度的样品其浓度为2.4mol%样品上转换荧光的峰强度是最强的,其中绿光比其它谱线更强。 相似文献
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《自然科学进展(英文版)》2022,32(5):594-601
Host material plays an important role in obtaining efficient photon upconversion and downshifting luminescence. Generally, fluoride and oxyfluoride glasses-based materials are used for high-efficiency photon upconversion. However, the poor thermal stability of fluoride glasses and the toxicity of fluorine ions limit their applications. In this report, Yb/Ho-doped CaSiO3 wollastonite phosphors have been demonstrated as efficient red-emitting upconversion phosphors. The phosphors have been synthesized by microwave hydrothermal process followed by heat treatment at 1050 ?°C in the air environment. 2M phase of the β-wollastonite has been confirmed by X-ray diffraction and Raman spectroscopy while the existence of the Yb and Ho dopants in the CaSiO3 lattice has been confirmed by X-ray photoelectron spectroscopy. The synthesized samples showed strong red upconversion emission centered at 662 ?nm and near-infrared downshifting emissions at 2016 ?nm upon 980 ?nm excitation. The emissions were found to depend significantly on the Ho concentration. Temporal evolution of the main emission bands was investigated to show that the energy transfer upconversion from Yb to Ho ions was responsible for the efficient upconversion and downshifting phenomenon. 相似文献
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