63: Data-guided molecular design of high-efficiency donor–acceptor pairs for organic solar cells

Abstract: Organic solar cells (OSCs) combine mechanical flexibility with chemically tunable molecular structures, making them attractive for emerging photovoltaic technologies. However, achieving high power conversion efficiency (PCE) remains challenging due to the complex interplay between molecular structure, electronic properties, and device performance. Here, we present a structure–property-guided approach to rationalize and accelerate the molecular design of high-efficiency donor–acceptor (D–A) pairs for non-fullerene OSCs. A curated dataset of 1,559 experimentally reported D–A combinations was assembled, integrating electronic descriptors (HOMO, LUMO, and optical bandgaps) with chemically meaningful structural descriptors related to molecular topology and substituent architecture. Interpretable data-driven models were employed to identify the dominant molecular features governing PCE. Beyond energy-level alignment, the analysis reveals that structural descriptors associated with molecular bulk and side-chain architecture play a critical role in charge transport and non-radiative loss suppression. High-throughput screening and bandgap engineering further identify optimal design windows, providing practical guidelines for the molecular design of next-generation organic photovoltaic materials.