聚合物及其异质结构中的光电转换研究

项目名称： 聚合物及其异质结构中的光电转换研究

项目编号： No.10804062

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 武器工业

项目作者： 高琨

作者单位： 山东大学

项目金额： 17万元

中文摘要： 聚合物太阳能电池是利用聚合物的光电转换效应将光能转化为电能的有机功能器件。如何提高器件的光电转换效率是当前物理和化学家们从理论和实验等方面共同研究的热点课题之一。基于目前有机器件中光电转换机理等方面存在的一些争论和问题，我们拟采用紧束缚模型结合非平衡格林函数的理论方法，对聚合物分子及其异质结构中的光电转换进行系统的研究。研究内容包括：PPV 衍生物、P3HT 等复杂分子物理模型的建立，探讨侧基和分子构型对这些分子能带结构、载流子输运特性的影响；通过引入脉冲电场模拟不同能量的光激发，研究聚合物分子及其异质结构中的光电转换动力学过程，进而明确光致载流子的产生根源；探讨聚合物异质结构中界面和带阶对载流子产生、输运和复合的影响。这些工作将有助于发现有机材料中更加丰富的物理内容，为开发具有窄带隙及高载流子迁移率的光敏材料，实现更高光电转换效率的聚合物太阳能电池等有机功能器件提供理论指导。

中文关键词： 聚合物太阳能电池；光电转换；异质结构；界面势

英文摘要： Polymeric solar cell is one of the organic functional devices, which can convert optical energy into electric energy due to the photoelectric effect. How to improve thephotoelectric conversion efficiency is still the focused question, although numerous experimental and theoretical works have been addressed by the physicists and chemists in these years. Based on some debates and questions in the photoelectric conversion mechanism, we will systematically investigate the photoelectric conversion in polymeric molecules and their heterostructures in the framework of the tight-binding model combined with the nonequilibrium Green's function formalism. The contents include: creation of the physical model for some complex molecules, such as the derivatives of PPV and P3HT; effects of side groups and molecular structures on the energy bands and transport properties in these molecules; study for the dynamical process of photoelectric conversion in the polymeric molecules and their heterostructures by introducing a femtosecond electric pump pulse to confirm the mechanism of charge carrier photogeneration; investigation for effects of the level offset and interfacial coupling on the charge carriers photogeneration, transport and recombination in polymeric heterostructures. Through this work, we will try to find much abundant functional properties of organic polymers. It will be helpful or instructional for development of light-sensitive materials with narrow energy gap and high charge carrier mobility. In addition, the work will provide a theoretical instruction for development of efficient polymeric solar cell, which has a higher photoelectric conversion efficiency.

英文关键词： polymeric solar cell; photoelectric conversion; heterostructure; interfacial potential