Charge transfer regulated by domain differences between host and guest donors in ternary organic solar cells

Abstract

A clear selection rule for the third component is the premise for improving the efficiency of ternary organic solar cells (T-OSCs), which is also the top priority for clarifying the working mechanism. Here, the concept of structural domains is borrowed to mark molecular characteristics, quantify structural information, and support the breakthrough of structural dimensions layer by layer to confirm whether the same/different structural domain and ratio will lead to essential changes in the role of the third component. It shows that the domain difference determines the effect degree of the ratio on the morphology, stacking site and interfacial arrangement from the cluster level to the electron state level. Furthermore, under a certain domain difference, the ratio can react in turn to regulate the internal charge transfer (CT) mode. We aim to establish the corresponding relationship between the selection of the third component and the CT mechanism, and reveal the essence of a trace amount of the third component in the photoelectric conversion process, providing a theoretical basis for the targeted selection of the third component for T-OSCs.