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本文系统地研究了顺式高强聚乙炔的Raman和发光光谱,根据其Raman和发光光谱随激发能量的变化规律,以及分子链之间距离的改变对这种变化规律的影响,证明了聚乙炔中存在着激发态的链间弛豫,井且,这种弛豫过程随着分子链之间距离的减小而被加快. 相似文献
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研究了3种非共轭PPV聚合物以及3种共轭PPV衍生物的吸收谱和发光光谱的特性。非共轭PPV聚合物上的侧链烷氧基团有着很强的供电子能力,对调节非共轭聚合物能带带隙有重要的影响,且离主链较近的碳原子对能带结构也有一定的影响。但当侧链上的碳原子数量很大,从7个小时一直变化到10小时,共轭PPV衍生物的吸收光谱和发光光谱变化较少,表明对能带结构影响小。 相似文献
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采用热处理方法提高MEH-PPV单层聚合物有机发光二极管发光性能的研究 总被引:1,自引:1,他引:1
对以MEH-PPV为发光层的单层聚合物有机发光二极管(OLED)器件在最佳条件下进行真空热处理,并用金相显微镜观察施加电压后器件的阴极表面形貌。发现处理后的器件阴极表面的气泡及黑斑明显减少。器件的发光性能显著提高。与未经处理的器件相比,最大相对发光强度提高了一个数量级、启亮电压降低了2.0V,半寿命提高了12.7倍。初步分析表明热处理方法提高器件发光性能的主要原因在于有效地减少了器件在工作过程中由于焦耳热产生的某些气体,从而减少阴极表面气泡及黑斑的出现,另一方面,热处理方法也增强了有机发光层与阴极接触界面的结合力,提高电子注入水平。 相似文献
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纳米MEH-PPV阵列的光致发光 总被引:1,自引:1,他引:0
以多孔氧化铝为模板,将可溶性发光聚合物聚(2-甲氧基-5-(2’-乙基己氧基)-1,4-对苯乙炔)(MEH-PPV)镶嵌在纳米孔中,制备出高发光效率的纳米发光聚合物阵列,其光学特性与MEH-PPV薄膜显著不同。纳米孔内的MEH-PPV分子链形成链束,链束中的分子链数目依赖于制备纳米MEH-PPV阵列所用溶液的浓度。相对于稀溶液,在由浓溶液制备的纳米MEH-PPV阵列中,MEH—PPV链束的分子链数目较多,链间作用使MEH-PPV的能带展宽,能隙减小,因而浓溶液获得的纳米MEH—PPV阵列的光致发光峰红移。热处理纳米MEH-PPV阵列的PL谱表明,纳米孔内的聚合物分子链的弛豫运动受到限制。 相似文献
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采用荧光光谱技术,测量了一种卟啉侧链聚合物:卟啉丙烯酸酯-苯乙烯共聚物(P[(por)A-S])的稳态和瞬态的发光性能.通过将聚合物P[(por)A-S]掺杂到有机玻璃(PMMA)中,研究了链间距离对于P[(por)A-S]发光性能的影响.结果表明:随着聚合物分子浓度增大,即链间距离减小,导致卟啉侧链基团之间的相互间作用增加,使其激发态无辐射跃迁几率增加,聚合物荧光强度减弱,激发态寿命缩短.讨论了上述过程产生的原因. 相似文献
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有机聚合物的紫外漂白,经过一系列复杂的光化学反应,会使聚合物薄膜的折射率和厚度降低。在此基础上,利用金属掩模对聚合物薄膜进行选择性紫外漂白,制备出了聚合物脊形条波导。紫外漂白不需要对聚合物薄膜进行光刻和腐蚀便可获得边缘和表面比较整齐和光滑的脊形条波导,对减少波导的散射损耗十分有利。本文介绍了利用紫外漂白和金属掩模方法制备侧链型聚合物DANS(4-dimethylamino-4’nitro-stlibene)-PMMA(polymethyl methacrylate)脊形条波导的工艺过程,并对关键工艺进行了讨论。 相似文献
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合成了一种新型的稀土配合物Eu0.5Tb0.5(TTA)3Phen,并采用原位乳液聚合法进一步制备了Eu0.5Tb0.5(TTA)3Phen/PMMA稀土聚合物。利用红外光谱仪(IR)、电子探针X射线能谱仪等对其结构进行了表征,利用扫描隧道电子显微镜(SEM)、荧光光谱仪(FS)等研究了其微观形貌,并探讨了其发光性能。结果表明,聚合物中PMMA与稀土部分Eu0.5Tb0.5(TTA)3Phen通过键合的方式结合, 仍保持Eu0.5Tb0.5(TTA)3Phen原有的发光特性;在365 nm紫外光的激发下,产生发光峰在611.8 nm附近、谱线带宽为10.4 nm的红光发射,发光亮度高,色纯度高;Eu0.5Tb0.5(TTA)3Phen/PMMA具有良好的发光性能,其发光强度与MMA加入的含量有关。 相似文献
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Olga Franco Ingo Orgzall Günter Reck Sabine Stockhause Burkhard Schulz 《Journal of Physics and Chemistry of Solids》2005,66(6):994-1003
The crystalline structures of two modifications of a compound containing the oxadiazole ring, 2,5-di-(4-aminophenyl)-1,3,4-oxadiazole (DAPO) were determined. One of these modifications contains water molecules in the crystal structure, which is observed for the first time for an oxadiazole crystal. Both crystals show an orthorhombic structure. The water free modification, DAPO I, belongs to the space group Pbca (61) and has the lattice parameters: a=13.461(5), b=7.937(3) and c=22.816(8) Å (CCDC 246608). The water containing pseudo-polymorph, DAPO II, has the space group Cmcm (63) and the lattice parameters: a=16.330(5), b=12.307(2) and c=6.9978(14) Å (CCDC 246609). To gain information on the inter molecular interactions within the crystals, X-ray experiments under compression at ambient temperature and under heating at vacuum conditions were performed. Neither DAPO I nor DAPO II undergo phase transitions in the ressure range up to 5 GPa, as could be concluded from X-ray and Raman experiments. X-ray and calorimetric studies indicate that DAPO II dehydrates into DAPO I under increasing temperature. Structural considerations suggest a two-stage process. The compression behavior of both substances is well described by the Murnaghan equation of state (MEOS) and the values of the bulk modulus and its pressure derivative are determined for these crystals. Additionally, in the case of DAPO I, also the thermal expansion coefficient α0 was measured. 相似文献
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Photophysical characterizations of 2-(4-biphenylyl)-5 phenyl-1,3,4-oxadiazole in restricted geometry
P.K. Paul 《Journal of luminescence》2008,128(1):41-50
Langmuir and Langmuir-Blodgett (LB) films of non-amphiphilic 2-(4-Biphenylyl)-5-phenyl-1,3,4-oxadiazole (abbreviated as PBD) mixed with stearic acid (SA) as well as with the inert polymer matrix poly(methyl methacrylate) (PMMA) have been studied. Surface pressure versus area per molecule (π-A) isotherm studies suggest that PBD molecules very likely stand vertically on the air-water interface and this arrangement allows the PBD molecules to form stacks and remain sandwiched between SA/PMMA molecules. At lower surface pressure, phase separation between PBD and matrix molecules occurs due to repulsive interaction. However, at higher surface pressure, PBD molecules form aggregates. The UV-vis absorption and steady-state fluorescence spectroscopic studies of the mixed LB films of PBD reveal the nature of the aggregates. H-type aggregate predominates in the mixed LB films, whereas I-type aggregate predominates in the PBD-PMMA spin-coated films. The degree of deformation produced in the electronic levels are largely affected by the film thickness and the surface pressure of lifting. 相似文献
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依据最弱受约束电子势模型及其微扰修正理论,计算了铍原子1s22pnd 1Po1 (n=3-50)双激发态系列能级和量子亏损。计算结果与已有的实验结果符合得很好。 相似文献
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采用密度泛函理论(DFT)对7-(3,6-二硝基-N-p-乙烯基苯基咔唑)香豆素分子做理论研究。用B3LYP/6-31G(d,p)对其几何结构进行优化,得到其最稳定构型及能量。在优化结构的基础上,对其进行频率分析得到了分子的红外光谱和拉曼光谱,并对谱线中的各峰值做了具体指认,同时也得到了分子的最高占据轨道(HOMO)和最低空轨道(LUMO)能隙为2.150eV。利用含时密度泛函理论(TDDFT)对该分子的激发态进行计算,得到最低十个跃迁允许的单激发态。对前线分子轨道最高占据轨道和最低空轨道分析得到,C-C原子之间形成了离域π键。研究结果表明:7-(3,6-二硝基-N-p-乙烯基苯基咔唑)香豆素是一种良好的有机半导体材料,并具有很好的发光性能。 相似文献
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报道了以N2激光为泵浦光源,获得激发态分子内质子转移(ESIPT)分子HBO的激光输出现象。其激光转换效率约为17%,调谐范围为495~540nm,最强的输出波长在510nm。以HBO的激发态分子内质子转移的光物理和光化学过程为基础,建立了HBO产生激光的动态模型,数值模拟了在宽带和窄带情况下激光输出的光谱特性和时间特性,理论计算值与实验观测值很好相符,同时证实了激发态分子内质子转移分子的激光脉冲宽度依赖于激发态分子内质子转移分子的酮式异构体的基态S′0的寿命 相似文献
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The effect of benzo‐annelation on intermolecular hydrogen bond and proton transfer of 2‐methyl‐3‐hydroxy‐4(1H)‐quinolone in methanol: A TD‐DFT study 下载免费PDF全文
Yanliang Zhao Meishan Wang Panwang Zhou Chuanlu Yang Xiaoguang Ma Zhe Tang Dongshuai Bao 《Journal of Physical Organic Chemistry》2018,31(5)
Excited‐state intermolecular or intramolecular proton transfer (ESIPT) reaction has important potential applications in biological probes. In this paper, the effect of benzo‐annelation on intermolecular hydrogen bond and proton transfer reaction of the 2‐methyl‐3‐hydroxy‐4(1H)‐quinolone (MQ) dye in methanol solvent is investigated by the density functional theory and time‐dependent density functional theory approaches. Both the primary structure parameters and infrared vibrational spectra analysis of MQ and its benzo‐analogue 2‐methyl‐3‐hydroxy‐4(1H)‐benzo‐quinolone (MBQ) show that the intermolecular hydrogen bond O1―H2?O3 significantly strengthens in the excited state, whereas another intermolecular hydrogen bond O3―H4?O5 weakens slightly. Simulated electron absorption and fluorescence spectra are agreement with the experimental data. The noncovalent interaction analysis displays that the intermolecular hydrogen bonds of MQ are obviously stronger than that of MBQ. Additionally, the energy profile analysis via the proton transfer reaction pathway illustrates that the ESIPT reaction of MBQ is relatively harder than that of MQ. Therefore, the effect of benzo‐annelation of the MQ dye weakens the intermolecular hydrogen bond and relatively inhibits the proton transfer reaction. 相似文献
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研究了激发态质子转移(ESPT)分子2-(2'-羟基苯基)苯并噻唑(HBT)在不同极性溶剂中的光开关行为,探讨了溶剂极性对HBT分子光开光效应的影响.揭示了光开关脉冲信号的形成原因,建立了基于光诱导HBT分子激发态非线性折射效应的皮秒全光开关的理论模型.根据对时间响应函数的理论计算和实验结果分析,确定了光开关脉冲信号下降前沿和上升后沿的形成机理以及影响因素,并提出了增强光开关信号下降前沿的关断深度,提升上升后沿的恢复速度的有效途径和方法.本文工作为制成皮秒量级关断,微秒甚至纳秒量级重新打开的快速全光开关器
关键词:
全光开关
2-(2'-羟基苯基)苯并噻唑(HBT)
激发态质子转移
非线性光学特性 相似文献