Design of acceptors with high mobility via substitutions on dimeric perylene diimide for organic solar cells: A theoretical study

Abstract

Abstract The aim of this work is to provide an in-depth study of the optical, electronic, and charge transfer properties for substituent effects on the dimeric perylene diimide (PPDI). The ground state geometry and relevant electronic properties of investigated molecules for photovoltaic applications were evaluated by the CAM-B3LYP/6–31G (d,p) method. The absorption spectra simulated at the TD-B3LYP/6–31 + G (d,p) level. The results reveal that different positions and amount of substituents significantly affect on the distributions of frontier molecular orbitals for PPDI. The different positions of the same substituent group affect the frontier molecular orbital energy and energy gap of PPDI slightly. The different positions and amount of substituents affect the absorption spectra of PPDI slightly. The calculated reorganization energies of electrons and holes for PPDI and its derivatives implied that their charge transfer rates are higher than that of the typical electron and hole transport materials, respectively. Moreover, we have also predicted the mobility of designed molecules with better performances.