新型高性能交联型树枝状有机二阶非线性光学材料的研究

Organic second-order nonlinear optical materials have advantages such as high electro-optic coefficient, fast response, ease of processing and so on, and shown their wide applications in electro-optic modulator, optical switches, optical information storage and so on. However, the strong dipole-dipole interaction between chromophores seriously affects the efficiency of converting the first-order hyperpolarizability of the chromophore into the macroscopic electro-optic coefficient, and the degradation of the electro-optic coefficient of the organic electro-optic material has been the technical bottleneck in this field. To solve these problems, this project introduces cross-linkable functionalized groups into dendritic chromophore molecules and constructed a novel chromophore-chromophore self-crosslinking electro-optic system. The previous experiments proved that the electro-optic coefficient and polarization orientation stability of the material were greatly improved by the increase of chromophore content and the post-crosslinking curing reaction. This project intends to further develop high performance cross-linked electro-optic materials. By constructing cross-linking systems consisting of light / heat-initiated chromophores-chromophores, chromophores-polymers and chromophores - small molecules, and optimizing of the first hyperpolarizability and the glass-transition temperature of the chromophore, the polarization voltage and polarization time and crosslinking temperature to reveal the inherent law of cross-linked electro-optic materials, and prepare electro-optic materials with high electro-optic activity and high stability, thus provide theory and technology for developing high-performance electro-optic materials and devices.

有机二阶非线性光学材料具有电光系数高、响应速度快以及可加工集成性好等优点，在电光调制器、光开关、光信息储存等领域有着广泛的应用。而发色团分子间强的偶极相互作用严重影响了微观一阶超极化率转换为宏观电光系数的效率，同时有机电光材料电光系数的衰减一直是该领域的技术瓶颈。针对这一难题，本项目将可交联的功能化基团引入树枝状发色团分子，构建了新型发色团-发色团自交联型电光材料。前期的实验证明通过增加发色团含量以及后交联固化反应，可以大幅提升材料的电光系数和极化取向稳定性。本项目拟进一步开展高性能交联型电光材料的研究。通过构建由光/热引发的发色团-发色团、发色团-聚合物以及发色团-小分子等多种交联体系，同时优化发色团一阶超极化率以及玻璃化转变温度、极化电压与时间以及交联温度等条件，以发现交联型电光材料所存在的内在规律，从而制备出高电光活性高稳定性的电光材料，为发展高性能电光材料及器件提供理论与技术。

有机二阶非线性光学材料具有电光系数高、响应速度快以及可加工集成性好等优点，在电光调制器、光开关、光信息储存等领域有着广泛的应用。而发色团分子间强的偶极相互作用严重影响了微观一阶超极化率转换为宏观电光系数的效率，同时高温下有机电光材料电光系数的衰减一直是该领域的技术瓶颈。如何提高发色团的电光系数（r33值）以及稳定性依旧是研究的重点。本研究通过设计新型的噻吩类衍生物以及双苯胺等电子给体，芴基异佛尔酮电子桥来提高发色团的一阶超极化率。同时，往给体和桥上引入苯基衍生物等隔离基团来减弱偶极-偶极相互作用，进一步提高了发色团的电光系数。将多个发色团分子通过化学键连接在一起，形成树枝状有机电光发色团，分子间的静电相互作用更加地减弱，发色团的极化效率进一步提高。为了提高发色团的稳定性，我们将芳环和氟芳香环引入了发色团的电子给体和电子桥，合成了二元自组装以及树枝状发色团体系。将交联的功能化基团蒽和丙烯酸酯分别连接在以四氢喹啉为给体的发色团的给体和桥上，形成了二元交联的发色团电光体系。极化取向后，分子间发生交联反应/分子间氢键作用，以化学键/氢键的形式形成发色团网络，固定住已经取向的发色团分子，材料的极化取向稳定性大幅提升。上述所合成的30余种电光材料的电光系数和稳定性都大幅的提升，非常有希望运用到先进的光电子器件中，同时为高性能发色团的设计合成提供了有效的指导作用。