结构规整D1-Ax(x=1,2,3)交替共聚物的能级调控及光伏特性研究

项目名称： 结构规整D1-Ax(x=1,2,3)交替共聚物的能级调控及光伏特性研究

项目编号： No.51503219

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 韩亮亮

作者单位： 中国科学院青岛生物能源与过程研究所

项目金额： 22万元

中文摘要： D-A共聚物是目前最高效的有机光伏(OPVs)给体材料，电荷转移态赋予D-A共聚物宽吸收光谱和高消光系数。但受体异质结中富勒烯衍生物能级的限制，一味追求窄带隙会导致给受体能级不匹配，最终降低开路电压(VOC)或者激子分离速率；而宽带隙虽能实现高VOC，却会面临能量损失的关键科学问题。能级和带隙的协同调控大大增加了给体材料的设计难度。前期工作基础发现，增加体系受体单元的比例能够降低材料的LUMO能级、窄化带隙，但几乎不影响其HOMO能级。基于此，本项目拟从能量损失这一关键问题着手，巧妙利用共轭作用离域D-A聚合物的LUMO，创新性地设计结构规整D1-Ax(x=1,2,3)交替共聚物，以x值变化梯度调节聚合物的LUMO能级，目的在于减小能量损失；与此同时，本项目还将深入展开x值影响聚合物带隙以及OPVs中VOC的研究，发现新的科学现象，阐明能级、带隙的协同调控对OPVs性能影响的关键机理。

中文关键词： D-A聚合物；有机太阳能电池；能级；带隙

英文摘要： Donor-acceptor (D-A) copolymers are considered as the most efficient organic photovoltaic (OPVs) electron donor materials, charge transfer state endows these materials wide absorption and high extinction coefficient. However, because of the fixed energy level of fullerene derivatives in the bulk heterojunction, employing super narrow bandgap donor materials may result in low open-circuit voltage (VOC) or exciton dissociation rate, on the contrary, wider bandgap will lead to energy loss in the OPVs. The coordinated regulation of energy level and bandgap increases the level of challenge for material design. Our previous work indicates the LUMO energy level of the material will be decreased and the bandgap becomes narrower when the electron withdrawing unit increases, however, the HOMO energy level can be influenced hardly. Therefore, we are committed to dealing with the energy loss problem, regular D1-Ax (x=1,2,3) alternating copolymers will be designed to delocalize the LUMO of the polymers, the LUMO energy level will be adjusted gradually by increasing the x value. Meanwhile, deeper study on how the x value can influence the badgap and VOC will be carried out. New scientific problem and mechanism about the coordinated regulation of energy level and bandgap by increasing the acceptor unit in the polymer backbone for OPVs application will be discussed.

英文关键词： donor-acceptor polymers;organic solar cells;energy level;bandgap