新型二维有机金属络合物纳米片的合成及其光电性质研究

Nanosheets with two-dimensional (2D) polymeric structures characterized by good absorbance and high carrier mobility owing to their unique electronic structure and physical properties, have recently attracted much attention in the field of photovoltaic devices. It has been reported that the properties of top-down 2D nanosheets prepared by exfoliation of bulk-layered crystalline mother materials are greatly limited by their mother materials. Compared with top-down nanosheets, the bottom-up nanosheets are generally fabricated directly from atomic, ionic and molecular components, for which the function can be adjusted through the selection of building components (ligands and metal ions). In this proposal, a series of organic ligands based on bis(dipyrrinato), triphenylene and terpyridine and corresponding 2D nansheets will be designed, synthesized, and characterized. By employing gas-liquid interfacial approach, both single-layer and multilayer 2D bottom-up nanosheets can be developed. The degrees of π-conjugated and absorption properties can be adjusted through the selection of the building components. The optical band-gap can be adjusted by the control of the thickness of the nanosheets (number of layers). The size and shape of the ordered nanopores can be regulated by the geometry of the organic ligands, which provide a new method for the doping with electron acceptors and forming a hybrid films with nano-sized and double-continuous interpenetrating network structure. Furthermore, the effective charge separation, the enhanced efficiencies of solar cells can be achieved. The proposal will develop the application of 2D nanosheets in the field of photovoltaic devices, and provide theoretical and experimental basis for the development of new organic photoelectric nanomaterials.

二维聚合物结构纳米片因本身独特的电子结构和物理特性而具备吸光率好、载流子迁移率高等特点，在光伏器件领域受到关注。已报道的“自上而下”法制备的二维纳米片，其性质极大受限于母体材料。而“自下而上”合成法可从分子、离子直接合成功能可调的二维纳米片。本项目拟设计合成一系列基于双联吡咯啉、三亚苯和三联吡啶的有机配体，采用“自下而上”合成法，通过“气-液”界面反应将有机配体与金属离子络合制备单层和多层二维有机金属络合物纳米片。通过改变构筑成分(有机配体和金属离子)调控其共轭程度和吸光性能；通过改变厚度调节其光学带隙；通过有机配体的几何形状调控其有序纳米孔径大小和形状，为与电子受体掺杂并形成纳米尺寸双连续互穿网络结构混合膜提供新的方法手段，从而实现探索有效电荷分离，改善电池效率的新途径。本项目将发展具有特殊光电性质的二维纳米片，探索其在光伏器件领域的应用，为开发新型的有机光电纳米材料提供理论和实验依据。

通过“自下而上”界面合成法，成功制备二维有机金属络合物纳米片，实现了纳米片在厚度和结构上的可控合成制备，为二维纳米片材料的制备提供新的方法和途径；研究了有机配体的结构与性能关系，探索了配体结构和与之配位的金属离子对纳米片性能的影响。通过“自下而上”合成法，成功制备了具有良好光电转换率的二维双(吡咯啉)金属络合物纳米片，研究所合成金属有机纳米片表面形貌，证明通过“自下而上”法所制备二维纳米片可大面积形成具有有序纳米孔道结构且形貌均匀的膜；对制备的纳米片的光吸收与其层积数的线性关系以及多层纳米片电极的光电响应等进行了测试，发现纳米片的光吸收与其层积数和厚度在一定范围内线性关系，光电响应性能良好，有很好的光电转换率，为后续这种二维膜的有效掺杂和改性，以及在光电等器件方面的应用提供了理论基础和可行性方案。通过“自下而上”可控制备多层纳米片的方法，成功合成制备出了一系列具有不同拓扑结构的电化学储能性质优良的金属有机二维纳米片，探索了纳米片的结构与储电性能的关系；通过研究“自下而上”法制备的金属有机纳米片的优良储电性能，其放电时间和比电容明显优于大部分传统已文献报道的电容器材料，为设计开发高能量密度、大功率、长寿命以及低成本的超级电容器提供理论和实验依据，进一步为实现太阳能光电转化-电能存储一体化应用提供理论指导和技术支持。