有机太阳能电池中电荷转移态动力学过程和电压损失之间关系的研究

有机太阳能电池中电荷转移（CT）态激子复合引起的电压损失限制了器件性能的进一步提升。因此，深入理解CT态复合动力学过程及该过程与CT态性质参数（如CT态密度和给受体分子间距）之间的关系对降低电压损失，提升器件性能至关重要。本项目将围绕这一关键基础科学问题开展，研究内容包括：（1）利用双层活性层器件CT态密度可调控的优势，厘清CT态密度与器件CT激子辐射复合速率之间的关系；（2）通过在给受体活性层之间引入惰性界面层并改变界面层的制备工艺来调控给受体分子间距，厘清给受体分子间距变化与器件CT态激子辐射、非辐射复合速率之间的关系。主要研究目标为：明确器件CT态密度及给受体分子间距与器件辐射、非辐射复合电压损失之间的关系。本项目的顺利实施，将加深对有机太阳能电池中电压损失机制的理解，并为降低电压损失进一步提高器件的能量转换效率提供切实可行的实验方案。

The key to further improve performance of organic solar cells is to reduce voltage losses. This requires a better understanding of the recombination dynamics of charge transfer (CT) states and its relation to the properties of CT states determined by the parameters including CT state density and donor/acceptor spacing. This proposal is about investigating the fundamental relationship between CT state parameters and voltage losses. ..More specifically:.(1).We take the advantage of bilayer organic solar cells, in which the CT state density is tunable, to understand the relationship between CT state density and the radiative decay rate of CT excitons..(2).We introduce a passive interlayer in between the donor and the acceptor layers in the bilayer solar cells, and adjust the physical properties of the interlayer via engineering modifications, to investigate the impact of changing donor/acceptor spacing on both radiative and non-radiative decay rates of CT states in the solar cells...The goal of this research proposal is to identify the relationship between the CT state properties, i.e., CT state density and donor/acceptor spacing, CT state dynamics and voltage losses in organic solar cells. A successfully execution of the research proposal will allow for a better understanding of the voltage loss mechanism in organic solar cells, and provide methods to further reduce voltage losses, and thus improve performance of organic solar cells.