Designing of Un-Fused Electron Acceptors with Enhanced Power Conversion Efficiency by Introducing Unique S–O Noncovalent Interaction

Abstract

Terminal units’ modification is an effective strategy for designing efficient un-fused nonfullerene acceptors (UF-NFAs) with enhanced power conversion efficiency (PCE). Nowadays, researchers are focused on designing new UF-NFAs that enhance the PCE of organic solar cells. In this line, efforts are being made to design new UF-NFAs for possible application on organic solar cells (OSCs). By doing terminal unit modification of the Cl-4F molecule, we have designed a new series of UF-NFA (ETPJ-1–ETPJ-4). Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) at the B3LYP/6-311G([Formula: see text]) level have been employed for the computation of various geometric and photovoltaic aspects. Energies of highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbitals (LUMO) with their band gap suggested that ETPJ-1–ETPJ-4 are effective contributors to the design of the efficient active layer of OSCs. Red-shift (near IR) in the absorption spectrum with easy excitation of exciton has been noted in ETPJ-1–ETPJ-4. Enhanced open circuit voltage with high fill factor percentage (FF%) was also noted for designed systems. Further, the PCE values of the ETPJ-1–ETPJ-4 are better than the reference molecule. So, we recommended a novel kind of unfused nonfullerene acceptors (NFAs) with unique S–O noncovalent interaction for possible application in OSCs.