Synergistic alteration of end-capped groups into central core fused perylene-based materials to boost their photovoltaic properties

Abstract

Non-fullerene organic chromophores are widely used in photovoltaic materials. In this study, the perylene-based molecules (PBI1-PBI8) with an A–π–A framework were designed by modifying the terminal acceptor of the reference compound (PBIR). Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations at the M06/6-311G(d,p) level were employed to optimize and verify their true minima structures. Further, the optimized structures were used for investigating the frontier molecular orbitals (FMOs), transition density matrix (TDM), density of states (DOS), open-circuit voltage (V_oc), and binding energy (E_b) to understand their optoelectronic and photovoltaic performances. The HOMO–LUMO energy gap of PBI1-PBI8 was obtained in a range of 2.546–2.610 eV, comparable to the PBIR reference (2.553 eV). Additionally, they showed wide absorption spectra as 571.540–599.972 nm in the gas phase and 598.871–615.031 nm in the chloroform solvent phase. The designed derivatives also exhibited lower binding energies (0.436–0.482 eV). All the new chromophores (PBI1-PBI8) showed a reasonable improvement in photovoltaic response as shown by their prominent open-circuit voltages. These results suggest that the novel perylene-based chromophores may be suitable candidates for highly efficient photovoltaic materials.