Investigating the optoelectronic properties of Perylene Diimide-based organic molecules for high-efficiency organic solar cells

Organic solar cells (OSCs) have garnered significant focus recently due to their highly efficient, low-cost manufacturing and capacity for energy conversion. Reports indicate a remarkable increase in OSC efficiency, rising from 4.1 % in 2010 to 25.21 % in 2022. However, the lack of suitable substances for hole transport remains a critical challenge in enhancing efficiency. In this context, a series of small molecules designated PDIM1, PDIM2, PDIM3, PDIM4, PDIM5, PDIM6, and PDIM7 have been developed, which serve as organic molecules. These molecules are based on PIDT donor structures incorporating acceptors directly at the center or with bridging units. The photovoltaic and optoelectronic properties of the molecules have been compared with the reference PDIR. All organic molecules exhibited lower energy gaps than the reference, enhanced electron density transfer, and high dipole moments. These findings facilitate the understanding of organic molecules' design methodologies for optimizing the electronic properties. This study establishes the potential for manufacturing high-efficiency OSCs using the PDIM4 molecules. The synthetic fabrication of these novel-designed molecules is required for researchers to advance PDI-based OSCs.