可溶液处理小分子高效有机太阳能电池给体材料及器件研究

Among many promising solar cell technologies, organic solar cells have demonstrated many advantages such as low cost, large area production by using roll-to-roll printing technique, and etc. Owing to the advantages of no batch to batch variation, versatile structures and easy controlling of optoelectronic property for small molecules, solution processed small molecule based organic solar cells have exhibited great potential for future application. Based on our previous works, firstly, we are proposing to design and synthesize series of solution processed small molecules with good absorption as the electron-donating materials in organic solar cells. The relationship between the molecule structures and absorption, energy level will be investigated. Secondly, the controlled factors among active layer morphologies, molecular aggregations and chemical structures will be studied then to obtain the relationship between device performances and molecule chemical structures. Thirdly, the photoelectrical dynamics process in the photovoltaic devices, especially focus on the impact of morphology on the exiton production, diffusion, separation and etc will be investigated. From these studies, the intrinsic factors between molecule structures and device performances will also be demonstrated and understood. High efficiency (＞10%) solution processed small molecule or oligomer based organic photovoltaic devices are expected to be achieved.

在众多可选的太阳能技术领域，有机太阳能电池具有成本低，柔性及可大面积印刷制备等许多优点，其中基于可溶液处理的小分子有机太阳能电池因小分子材料没有批次问题，结构多样，光电性能易调控等优点。本项目拟在我们前期工作基础上，优化设计合成一系列具有良好吸收的小分子给体材料，研究其化学结构和光谱吸收及能带结构等性能之间的关系，考察和揭示活性层形貌及分子聚集态的控制因素以及与分子结构之间的关系，从而获得器件性能和分子结构之间的构效关系；在上述基础上，分析研究器件中的光电动力学特别是激子产生、扩散、分离等过程与分子和形貌间的关系，揭示分子结构变化导致形貌不同和效率差异的本质因素，找出影响材料和器件效率的关键步骤，从而进一步指导分子的设计合成，获得几个或一批明星分子，并获得效率（＞10%）的有机小分子或寡聚物材料和优化的器件。

太阳能电池是当前绿色能源研究与应用领域最有发展前景的方向之一。相比与传统的无机太阳能电池，有机太阳能电池具有柔性，半透明以及可大面积低成本印刷制备等优点，成为近年来研究的热点。本项目设计合成了系列具有良好太阳光吸收和较高载流子迁移率的小分子光伏给体材料，其中DR3TSBDT，DRCN5T等已成为有机太阳能电池研究领域的明星分子；通过考察不同烷基链长度和不同拉电子末端基团等分子物理性能和光伏器件性能的影响，系统深入研究了可溶液处理小分子化学结构、微观形貌与光电性能之间的构效关系；通过分子设计优化和光伏器件制备条件优化，获得了单层器件光电转化效率超过10%，叠层光伏器件达到12%以上，顺利完成了项目拟定的效率指标。项目三年来发表包括Nature Photon., J. Am. Chem. Soc., Adv. Mater.,等在内的SCI论文30余篇，获得了国内外同行的广泛关注，有力推动了该领域的发展。