Theoretical investigation of Non-Fused Ring Electron Acceptors (NFREAs) for organic solar cells applications

Abstract

Non-fullerene acceptors (NFAs) have emerged as promising alternatives to fullerene-based acceptor molecules for organic solar cell (OSC) application due to their tunable electronic properties, strong absorption, and improved stability. In this work, a combined density functional theory (DFT) and classical molecular dynamics (MD) simulations were carried out on a new class of non-fused ring electron acceptors (NFREAs) to study their structural, electronic, molecular packing, and charge transport properties. DFT and time-dependent DFT (TD-DFT) calculations were employed to evaluate the ground-state and excited-state properties of individual molecules. To gain more insights into the bulk-phase behavior, selected high-performing NFREAs were blended with the conjugated polymer (PM6) and carried out molecular dynamics simulations to examine the molecular packing behaviour. The MD-derived geometries were further used to calculate the charge transport characteristics of the NFREAs. Overall, this theoretical study provides valuable insights into the structure-property relationships governing non-fused ring electron acceptors and offers guidance for the rational design of efficient materials for organic solar cells.