本项目以研究有机小分子太阳能电池给体-受体材料的二维表界面组装规律与电荷转移，从而引导太阳能电池的分子设计，优化本体异质结微观结构和电荷转移过程，以此提高电池的光电转换效率为目的。我们拟采用一系列的研究手段来直观地探究本体异质结活性层的微纳结构、给受体分子之间作用方式和电荷转移机制。我们拟利用扫描隧道显微技术、DFT理论计算和原子力显微技术研究给受体分子之间的作用方式和排布规律，从分子水平研究纳米到微米级别微观结构之间的内在联系。在此基础上，利用时间分辨光谱、扫描隧道谱、常规光谱等方法从微观到宏观，静态到动态全方位立体地研究给体-受体之间的电荷转移机制。以此探究出给-受体小分子研究体系的微观形貌、作用方式、排布规律和电荷转移之间的关系，总结出一些普适性规律。并以此引导有机小分子太阳能电池的设计，优化有机小分子太阳能电池本体异质结活性层微纳结构和电荷转移，从而提高电池的光电转换效率。

The aim of this project is to guide molecular design and optimize the microstructures and charge transfer of bulk heterojunction, so as to improve the photoelectric conversion efficiency of solar cells through exploring the interfacial self-assembly and charge transfer of donor-acceptor materials of small molecule organic solar cells. Therefore, lots of methods are utilized to intuitively investigate the nanostructures, molecular packing, and the charge transfer mechanisms. We will use scanning tunneling microscopy, DFT theoretical calculation, and atomic force microscopy to investigate the molecular interactions and packing fashion, and find the internal relationships of structures from the nanoscale to micron scale at molecular level. Furthermore, time resolved spectroscopy, scanning tunneling spectroscopy, and conventional spectral analysis are utilized to explore the charge transfer mechanisms of the donor-acceptor systems from microcosmos to macrocosmos and statics to dynamics. On the basis of the researches mentioned above, the relationship among microstructures, molecular packing, and the charge transfer is summarized to obtain some rules. These rules could play vital roles in designing solar cells and optimizing the microstructures and charge transfer of bulk heterojunction, which could improve the photoelectric conversion efficiency of solar cells.