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微波吸收法研究ZnS:Mn粉末发光材料的光电子瞬态过程 总被引:2,自引:2,他引:0
本文采用微波吸收介电谱技术,测量了ZnS:Mn材料受到紫外超短脉冲激光激发后,其光生电子的瞬态衰减过程,得到了ZnS:Mn材料光电子衰减时间分辨谱.分析表明,光电子衰减由快慢两个衰减过程组成,快过程持续时间约为10ns,慢过程近似为指数衰减过程.Mn的掺杂浓度对导带光电子的寿命有明显的影响,慢过程光电子寿命随着Mn掺杂浓度的增加而呈下降趋势,掺杂浓度由0.10;质量分数增加到1.00;质量分数时,慢过程的光电子寿命由779ns下降到363ns,下降了近一倍.这是由于随着Mn掺杂浓度的提高,Mn2+发光中心的密度增加,导带光电子与发光中心的碰撞几率增大,寿命降低. 相似文献
226.
通过自由基共聚成功地将具有高磷光发光效率的-苯基-2,2’-二联吡啶(C^N^N)Pt(Ⅱ)苯乙炔络合物共价键合在聚苯乙烯高分子骨架上,得到了发射磷光的聚合物.实验表明,发光聚合物基本保持了多吡啶铂络合物单体的光谱性质.具有与小分子相当的光致发光效率. 相似文献
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Dr. Camilla Gustafsson Dr. Hamid Shirani Petter Leira Dr. Dirk R. Rehn Dr. Mathieu Linares Prof. K. Peter R. Nilsson Prof. Patrick Norman Prof. Mikael Lindgren 《Chemphyschem》2021,22(3):323-335
Anionic pentameric thiophene acetates can be used for fluorescence detection and diagnosis of protein amyloid aggregates. Replacing the central thiophene unit by benzothiadiazole (BTD) or quinoxaline (QX) leads to large emission shifts and basic spectral features have been reported [Chem. Eur. J. 2015 , 21, 15133-13137]. Here we present new detailed experimental results of solvent effects, time-resolved fluorescence and examples employing multi-photon microscopy and lifetime imaging. Quantum chemical response calculations elucidate how the introduction of the BTD/QX groups changes the electronic states and emissions. The dramatic red-shift follows an increased conjugation and quinoid character of the π-electrons of the thiophene backbone. An efficient charge transfer in the excited states S1 and S2 compared to the all-thiophene analogue makes these more sensitive to the polarity and quenching by the solvent. Taken together, the results guide in the interpretation of images of stained Alzheimer disease brain sections employing advanced fluorescence microscopy and lifetime imaging, and can aid in optimizing future fluorescent ligand development. 相似文献
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A new luminescent coordination polymer [Zn(tdc)(pbim)]n 1(tdc = 3,4-thiophenedicarboxylate, pbim = 1,3-bis(benzimidazol-1ˊ-yl)propane) has been synthesized under hydrothermal conditions. The compound crystallizes in monoclinic system, space group P21/c with a = 8.4840(9), b = 16.4913(17), c = 14.9234(16) A, β = 95.8870(10)°, V = 2077.0(4) A3, Z = 4, Mr = 511.84, Dc = 1.637 Mg/m3, μ = 1.324 mm-1, F(000) = 1048, the final R = 0.0361 and w R = 0.0824 for 3656 observed reflections with I 2(I). Structural analyses reveal that 1 exhibits a onedimensional(1D) double chain, which is further connected into a two-dimensional(2D) supramolecular architecture by π-π stacking interactions. The results indicate that H2 tdc and pbim ligand are effective building blocks in constructing polymers with diverse architecture. Solid state properties for 1, such as infrared spectroscopy, elemental analyses, thermal stability and luminescent property, have also been investigated. 相似文献
229.
Dr. Wei Liu Zhennan Zhou Haibo Li Yi Lv Hua Tong Jialin Zhu Prof. Gangfeng Ouyang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(71):e202202478
Copper(I) halide organic-inorganic hybrid luminescent materials have many advantages, such as diverse structure, facile synthesis, high luminescent efficiency, tunable optical performance, etc., and show a broad application prospect in energy-saving lighting, display and other fields. However, compared with commercial rare-earth-metal-based phosphors, the reported hybrids generally suffer from poor stability and low luminescent efficiency, which are the bottleneck problem of their practical application. With the aim of developing high-performance organic-inorganic hybrid luminescent materials, a new synthesis strategy has been reported. This strategy can systematically design and synthesis copper(I) halide ionic hybrid structures by combining the covalent bonding and ionic bonding between inorganic and organic components into one structure, and use their synergistic effect to optimizing their properties. This design method is expected to develop high-performance organic-inorganic hybrid luminescent materials, promote the in-depth understanding of this field, and provide new ideas for the optimization of other types of hybrid materials. 相似文献
230.
Fahad Mateen Heemuk Oh Wansu Jung Sae Youn Lee Hirotsugu Kikuchi 《Liquid crystals》2018,45(4):498-506
Polymer dispersed Liquid crystal (PDLC) windows are regarded as a good choice for curtain-free windows. However, conventional PDLC needs external electricity to operate, which causes extra energy consumption. These devices cannot be combined with traditional solar cells for energy savings. In this study, a new design of luminescent solar concentrator (LSC)-based PDLC device is presented. In particular, we successfully demonstrate that the PDLC can be integrated with LSC as its back scatter and potentially contributes towards the enhancement of power output by minimising backside light losses. Multi-luminophore LSC is employed to increase the absorption of air mass 1.5 solar irradiance. The edge emission measurements show multiple-luminophore-based PDLC-LSC gives the maximum edge emission power which is 1.7 times more than that of single luminophore-based PDLC-LSC device. Photocurrent measurements are also performed as an additional evidence for the improved performance of PDLC-LSC device. Finally, the visual properties of PDLC-LSC devices are evaluated to realise the compatibility of using such devices in the built environment. 相似文献