共查询到18条相似文献,搜索用时 609 毫秒
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通过熔融法以及热处理,制备了Ce~(3+)掺杂含Li Lu F_4纳米晶的透明氟氧微晶玻璃。XRD结果表明,玻璃中析出的晶相为Li Lu F_4,其晶粒大小随热处理温度的升高和时间的延长而变大。在330 nm紫外光激发下,Ce~(3+)掺杂的氟氧玻璃和Li Lu F4微晶玻璃的发射为一峰值波长为370 nm的宽带光谱。微晶玻璃的发光强度显著高于未经过热处理的基础玻璃,并且随着热处理温度的升高及时间的延长,微晶玻璃的发光逐渐增强。微晶玻璃的370 nm发射的荧光寿命均长于基础玻璃的。 相似文献
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《发光学报》2021,(6)
通过熔融淬火和后续热处理,成功制备了Tb~(3+)掺杂含LaF_3纳米晶透明锗酸盐微晶玻璃。详细研究了所制备的玻璃和微晶玻璃的发光性质。X射线衍射结果表明,玻璃基体中析出的晶相为纯LaF_3晶体,晶粒尺寸在16~21 nm之间。在377 nm紫外光和X射线激发下,Tb~(3+)掺杂含LaF_3纳米晶的微晶玻璃比Tb~(3+)掺杂的锗酸盐玻璃表现出更强的绿光发射,且绿光发射强度随热处理温度升高和时间的延长而增强。微晶玻璃在X射线激发下的最大积分发光强度约为商用闪烁晶体Bi_4Ge_3O_(12)的40.3%。本研究表明,掺Tb~(3+)含LaF_3纳米晶锗酸盐微晶玻璃在X射线探测中具有潜在的应用前景。 相似文献
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通过熔融淬火和后续热处理,成功制备了Tb^(3+)掺杂含LaF_(3)纳米晶透明锗酸盐微晶玻璃。详细研究了所制备的玻璃和微晶玻璃的发光性质。X射线衍射结果表明,玻璃基体中析出的晶相为纯LaF_(3)晶体,晶粒尺寸在16~21 nm之间。在377 nm紫外光和X射线激发下,Tb^(3+)掺杂含LaF_(3)纳米晶的微晶玻璃比Tb^(3+)掺杂的锗酸盐玻璃表现出更强的绿光发射,且绿光发射强度随热处理温度升高和时间的延长而增强。微晶玻璃在X射线激发下的最大积分发光强度约为商用闪烁晶体Bi_(4)Ge_(3)O_(12)的40.3%。本研究表明,掺Tb^(3+)含LaF_(3)纳米晶锗酸盐微晶玻璃在X射线探测中具有潜在的应用前景。 相似文献
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《光学学报》2010,(4)
通过高温熔融法和热处理成功制备了白光发光的Eu~(2+)/Eu~(3+)掺杂SiO_2-Al_2O_3-ZnO-K_2CO_3微晶玻璃。测试了微晶玻璃的X射线衍射谱(XRD)、激发光谱和荧光光谱。研究发现,X射线衍射谱表明了玻璃基质中存在β-Zn_2SiO_4纳米晶粒,根据XRD结果和Scherrer公式计算得到β-Zn_2SiO_4晶粒大小约为35 nm。在紫外光激发下,观察到强烈的宽带蓝光(400~460 nm)和红光(574,587,611,650和700nm)发光,分别对应Eu~(2+)的4f~65d→4f~7能级跃迁以及Eu~(3+)的~5D_0→~7F_J(J=0,1,2,3,4)能级跃迁,与未热处理玻璃样品相比较,微晶玻璃的发光强度大大增强。研究结果表明,Eu~(2+)/Eu~(3+)掺杂的SiO_2Al_2O_3-ZnO-K_2CO_3晶玻璃是一种白光LED潜在的基质材料。 相似文献
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采用高温熔融法和热处理工艺制作了含有GdF3纳米晶的氧氟微晶玻璃。在386 nm激发下,Dy3+掺杂氧氟微晶玻璃的发光强度明显增强,且蓝光对黄光的发光强度比逐渐增大,表明Dy3+已进入到GdF3纳米晶中。在980 nm激光器泵浦下,Er3+,Yb3+共掺氧氟微晶玻璃的上转换发光随着热处理温度的升高明显增强,Er3+的上转换发光出现明显的Stark分裂现象,这亦说明Er3+已进入到GdF3纳米晶相中。通过研究上转换发光强度与泵浦功率的关系,确定绿光上转换发光为双光子过程。 相似文献
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通过传统的熔融淬火技术以及后续热处理法制备了Tm3+/Yb3+共掺含LaF3纳米晶锗酸盐微晶玻璃。通过DTA和XRD研究其热性质和LaF3纳米晶的可控析出。通过透过光谱和上转换发光光谱研究了玻璃的光学性能。利用荧光强度比(FIR)技术研究了微晶玻璃样品在980 nm激光激发下的上转换发光光谱与温度的依赖关系。研究发现,该微晶玻璃样品在313~573 K温度范围内的最大绝对灵敏度Sa和最大相对灵敏度Sr分别为2.6×10-4K-1(573 K)和2.3×10-2K-1(313 K)。结果表明,Tm3+/Yb3+共掺含LaF3纳米晶锗酸盐微晶玻璃在温度传感领域具有潜在的应用前景。 相似文献
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氧和氩等离子辅助电子束蒸发制备高质量ZnO薄膜 总被引:6,自引:0,他引:6
采用等离子辅助电子束蒸发技术制备高纯金属锌膜,然后在氧气气氛下经高温热处理得到氧化锌的多晶薄膜。X射线衍射谱的结果表明:未经热氧化样品由金属锌和氧化锌纳米晶组成,随着热氧化温度的升高氧化锌纳米晶粒长大,形成纳米氧化锌多晶薄膜且薄膜结晶性增强;光致发光谱表明:样品均具有较强的紫外自由激子发光。由于未经热氧化样品中氧化锌纳米晶粒较小,具有较强的量子限域效应,因而经高温氧化后样品发光峰有较大红移。随着热氧化温度的进一步升高,束缚激子发射随热氧化温度升高而减弱,且发光峰位随热氧化温度升高出现蓝移;变温光致发光谱表明:紫外发光主要来自自由激子发射。 相似文献
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Spectroscopic properties and mechanism of Tm^3+/Er^3+/Yb^3+ co-doped oxyfluorogermanate glass ceramics containing BaF2 nanocrystals
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Transparent Tm^3+/Er^3+/yb^3+ co-doped oxyfluorogermanate glass ceramics containing BaF2 nanocrystals are prepared. Under excitation of a 980-nm laser diode (LD), compared with the glass before heat treatment, the Tm^3+/Er^3+/yb^3+ co-doped oxyfluorogermanate glass ceramics can emit intense blue, green and red up-conversion luminescence and Stark- split peaks; X-ray diffraction (XRD) and transmission electron microscope (TEM) results show that BaF2 nanocrystals with an average diameter of 20 nm are precipitated from the glass matrix. Stark splitting of the up-conversion luminescence peaks in the glass ceramics indicates that Tm^3+, Er^3+ and (or) Yb^3+ ions are incorporated into the BaF2 nanocrystals. The up-conversion luminescence intensities of Tm^3+, Er^3+ and the splitting degree of luminescence peaks in the glass ceramics increase significantly with the increase of heat treat temperature and heat treat time extension. In addition, the possible energy transfer process between rare earth ions and the up-conversion luminescence mechanism are also proposed. 相似文献
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Upconversion Luminescence of Er3+ Ions in Transparent Germanate Glass Ceramics Containing CaF2 Nanocrystals
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The visible upconversion and near-infrared luminescence of Er3+ ions in germanate glass ceramics containing GaF2 nanocrystals are investigated. The nanocrystals are characterized by x-ray diffraction (XRD) and transmission electron microscopy, showing their mean sizes less than 20hm. High transmittance of the glass ceramics is displayed by absorption spectra. The upconversion luminescence intensity in the glass ceramics increases significantly with increasing temperature. Both the shifts of the XRD peaks and the Stark-split shown in the luminescence spectra indicate the entrance of the Er3+ ions into the CaF2 nanocrystals, which is confirmed by a Judd-Ofelt analysis. Possible mechanisms of the upconversion luminescence are analyzed. 相似文献
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Rare-earth doped borate glasses and glass ceramics are investigated for their potential as photon converters. Thermal processing of the as-made glass results in the formation of nanocrystals therein. For optical activation, the glasses are doped with Eu3+ and Tb3+, both enabling an intense emission under ultraviolet excitation. Differential scanning calorimetry and X-ray diffraction are applied to analyze the crystallization behavior. Compared to the undoped glass, the glass transition temperature as well as the crystallization temperature are increased with Eu3+ doping. Upon thermal processing of the as-made glasses, the transmittance is significantly reduced. Preliminary photoluminescence quantum efficiency measurements yield lower values for the glass ceramics. 相似文献
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Eu3+ ion doped chlorophosphate glass ceramics containing nanocrystals were successfully prepared, and their spectroscopic characterizations were done using absorption, excitation and emission spectra. For the crystallized samples, X-ray diffraction (XRD) and transmission electron microscopy (TEM) experiments evidenced the formation of CaCl2 nanocrystals. The absorption and emission spectra investigations indicate that a considerable amount of Eu3+ ions was trapped in CaCl2 nanocrystals, and therefore an efficient up- and down-frequency conversion was observed. The comparative spectroscopic studies of Eu3+ doped samples suggest that the investigated glass ceramics systems are potentially applicable as frequency-conversion photonics devices. 相似文献
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The Eu 2+ /Tb 3+ /Sm 3+ co-doped oxyfluoride glass ceramics containing Ba2LaF7 nanocrystals are prepared in the reducing atmosphere.The X-ray difiraction results show that Eu 2+ ,Tb 3+ and Sm 3+ ions are enriched into the precipitated Ba2LaF7 nanophase after the annealing process.It deduces efficient energy transfers from Eu 2+ to Tb 3+ and Sm 3+ and intenses warm white luminescence of the glass ceramics. Comparing with the glass,the luminescence quantum yield of the glass ceramics is also enlarged by about 3 times.This demonstrates the potential white light-emitting diode application of the glass ceramics produced in this letter. 相似文献
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Ce3+ doped transparent glass ceramics containing BaYF5 nanocrystals were prepared by controlled heat treatment of 45SiO2–15Al2O3–10Na2O–24BaF2–6Y2O3–0.5Ce2O3 (mol%) glass. X-ray diffraction and transmission electron microscopy data have revealed the formation of BaYF5 nanocrystals. Both photoluminescence and X-ray excited luminescence spectra have shown a blue-shift of the emission band of Ce3+ on ceramization, which is consistent with the Ce3+ environment evolving from a glassy oxide to a fluoride phase. The luminescent intensity of Ce3+ ions in the transparent glass ceramics is greatly enhanced compared with the precursor glass under ultraviolet and X-ray excitation. This could be attributed to the Ce3+ ions present in the BaYF5 crystalline phase. 相似文献
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利用高温固相法制备了Tm3+/Yb3+共掺杂的氟氧化物玻璃和玻璃陶瓷材料,在980 nm的激光激发下,样品发射出明亮的蓝色上转换荧光。通过对玻璃和玻璃陶瓷样品的对比,发现Tm3+离子和Yb3+离子之间存在着Tm3+(3H4)→Yb3+(2F5/2)的反向能量传输通道,并且与晶场有较强的依赖关系。分析了在玻璃和玻璃陶瓷中蓝色上转换发光过程,随着敏化剂Yb3+浓度的增加,在玻璃中正向和反向能量传递的竞争作用使得Tm3+离子在Yb3+离子的最佳浓度时上转换发光最强;而在玻璃陶瓷中, Tm3+离子的上转换发光始终随着Yb3+离子的浓度增加而增强。 相似文献