Molecular Controlling the Transport Properties for Benzothiadiazole-Based Hole Transport Materials

Abstract

Three experimental hole transport materials containing fluorine-substituted benzothiadiazole-based organic molecules (Jy5–Jy7) have been studied to explore the relationship between photoelectric performances and the core structures of hole transport materials (HTM). By employing density functional theory (DFT) and time-dependent density functional theory (TD-DFT), it was found that the substitution of the hydrogen atom by fluorine atom in the core structure can significantly boost the hole mobility; and the replacement of core structure from electron-withdrawing group to electron-donating group has strong influence on the increment of LUMO level energy, ability to preventing electron-backflow, molecular stability and oscillator strength of HTM molecules. We hope our investigation can provide theoretical guidance to reasonably optimize HTM molecules for perovskite solar cells.