光子晶体对发光材料光致发光调控的研究

发布时间：2018-09-06 14:50

【摘要】：二十世纪六十年代初,人类进入高度信息化社会,现代信息技术飞速发展,许多新型材料也应运而生。而现代信息技术产业的发展,离不开发光材料,正是发光材料的不断革新变化,才使得现代信息技术产业蓬勃发展。因此,从多方面对发光材料进行研究,显得尤为重要。全世界有很多课题组致力于从物理、化学、材料、电子等交叉学科领域,对发光材料进行研究探索,并取得了许多显著的成果。在研究发光材料的光物理过程的时候,常常着重探讨对光物理过程的调控,通过对该方面的研究,可以帮助研究人员寻找提升发光材料荧光产率的方法。对于发光材料在制备成器件的过程中常见的诸如易结晶、量子产率低等问题,亦可通过研究发光材料的光物理过程来探寻其中原因,从而寻找解决办法,拓宽发光材料的应用领域。同时,相关研究成果能够为新型发光材料的研发及应用提供理论储备。本文详细研究了光子晶体对有机小分子染料和金纳米团簇两种材料光致发光的调控作用,从稳态和动态两个角度展开研究。本文主要内容如下:1.详细介绍了三维蛋白石聚甲基丙烯酸甲酯(PMMA,poly-methyl-methacrylate)光子晶体的制备方式,这种光子晶体具有微孔结构和位置可控的光子带隙。两种结构都能够调控渗入到三维蛋白石PMMA光子晶体中的有机小分子染料的光致发光特性。处于聚集态的有机小分子染料会因为分子与分子之间距离很近,造成较强的分子间相互作用,产生聚集诱导荧光淬灭现象。但是,在聚集态的情况下引入三维蛋白石PMMA光子晶体,因其孔隙作用,能够有效增大分子间距离,减小分子间相互作用,抑制其聚集诱导荧光淬灭现象,从而达到令有机小分子染料光致发光增强的效果。对于两种混合后满足能量转移条件的有机小分子染料,光子晶体的光子带隙位置选取,能够影响两种有机小分子染料之间的能量转移效率。综上所述,选取合适的光子带隙,则能够通过抑制给体的自发辐射,达到提高给受体之间能量转移效率的作用。2.详细介绍了二维掺杂香豆素6(C-6,coumarin 6)PMMA光子晶体的制备过程,并在二维掺杂C-6 PMMA光子晶体微球表面蒸镀了半透明的银壳层。通过实验研究可以发现,该种二维掺杂C-6光子晶体能够受激发光,并且其发光性能要优于聚集态C-6的发光性能。通过分析我们构造的二维掺杂C-6光子晶体与半球状银壳层所组成的系统,可以发现,能量转移和局域等离子体共振能够影响二维掺杂C-6光子晶体的光致发光特性。当通过在二维掺杂C-6光子晶体表面蒸镀半透明银壳层之后,我们发现在二维掺杂C-6光子晶体与半球状银壳层之间存在能量转移,并且染料分子的光致发光光谱波形能够被局域等离子体共振影响。3.我们利用自下而上的自组装法(Bottom-up法)合成了一种具有硫醇盐核壳结构的金纳米团簇(Au NCs,Au(0)@Au(I)-thiolate core-shell nanoclusters),并且研究了这种金纳米团簇的光致发光机制。我们在对所有样品的稳态发射光谱和不同波长下探测的荧光动力学曲线进行分析之后,确认了这种金纳米团簇的光致发光机制,并以此为依据,进一步研究了改善这种金纳米团簇光致发光性能的方法。依据聚集诱导荧光增强效应,我们发现,可以用酒精来稀释浓的金纳米团簇水溶液,受溶剂诱导聚集(solvent-induced aggregation)影响,单分散的金纳米团簇会聚集在一起,进而达到改善金纳米团簇发光特性的效果。同时,将金纳米团簇水溶液渗入到三维蛋白石PMMA光子晶体中之后,在提高金纳米团簇的光致发光的同时,还能够有效抑制金纳米团簇的浓度淬灭,从而进一步改善了金纳米团簇的发光特性。
[Abstract]:In the early 1960s, mankind entered a highly informationized society, modern information technology developed rapidly, and many new materials came into being. The development of modern information technology industry can not be separated from luminous materials. It is the constant innovation and change of luminous materials that make the modern information technology industry flourish. Therefore, from many aspects to the development of modern information technology industry. Many research groups around the world have devoted themselves to the research and exploration of luminescent materials in the fields of physics, chemistry, materials and electronics, and have made many remarkable achievements. The research in this field can help researchers to find ways to improve the fluorescence yield of luminescent materials. For the common problems in the process of preparing devices, such as easy crystallization and low quantum yield, we can also explore the reasons by studying the photophysical process of luminescent materials, so as to find solutions and broaden the luminescence. At the same time, the related research results can provide a theoretical reserve for the development and application of new luminescent materials. In this paper, photonic crystals on organic small molecule dyes and gold nanoclusters of two materials photoluminescence modulation role, from the steady-state and dynamic point of view to carry out research. The main contents of this paper are as follows: 1. The preparation methods of three-dimensional opal poly methyl methacrylate (PMMA) photonic crystals are introduced in detail. The photonic crystals have microporous structure and position-controlled photonic band gap. Both structures can control the photoluminescence properties of organic small molecular dyes infiltrated into three-dimensional opal PMMA photonic crystals. Aggregation-induced fluorescence quenching occurs when small organic dyes in the aggregated state are very close to each other. However, the introduction of three-dimensional opal PMMA photonic crystals in the aggregated state can effectively increase the distance between molecules and reduce the intermolecular interaction because of its pore interaction. In order to enhance the photoluminescence of organic small molecule dyes, the selection of photonic band gap position of photonic crystals can affect the energy transfer efficiency between two organic small molecule dyes. A suitable photonic band gap can improve the energy transfer efficiency between donor and acceptor by inhibiting the spontaneous emission of donor. 2. The preparation process of two-dimensional coumarin-6 (C-6, coumarin-6) PMMA photonic crystal was introduced in detail, and a translucent silver shell was evaporated on the surface of two-dimensional C-6 PMMA photonic crystal microspheres. The experimental results show that the two-dimensional doped C-6 photonic crystal can be excited and its luminescent properties are better than those of the aggregated C-6 photonic crystal. Photoluminescence properties of doped C-6 photonic crystals. When translucent silver shell was evaporated on the surface of two-dimensional doped C-6 photonic crystals, we found that there was energy transfer between two-dimensional doped C-6 photonic crystals and hemispherical silver shell, and the photoluminescence spectrum waveforms of dye molecules could be influenced by local plasma resonance. A gold nanocluster (Au NCs, Au (0) @Au (I) -thiolate core-shell nanoclusters) with thiol salts core-shell structure was synthesized by bottom-up self-assembly (Bottom-up) method, and the photoluminescence mechanism of the gold nanoclusters was studied. We detected the fluorescence of the gold nanoclusters at different wavelengths and steady-state emission spectra of all samples. The photoluminescence mechanism of the gold nanoclusters was confirmed by analyzing the photodynamic curves, and the methods to improve the photoluminescence properties of the gold nanoclusters were further studied. Monodispersed gold nanoclusters can be aggregated to improve the luminescent properties of gold nanoclusters under the influence of solvent-induced aggregation. At the same time, the water solution of gold nanoclusters can be infiltrated into three-dimensional opal PMMA photonic crystals to improve the photoluminescence of gold nanoclusters, and at the same time, it can effectively suppress the photoluminescence of gold nanoclusters. The concentration of gold nanoclusters is quenched, which further improves the luminescence properties of gold nanoclusters.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O482.3

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