[3PS-068]
Identification of Differences in Charge Carrier Behavior Mechanisms between Organic Semiconductor-Based Photovoltaic and Photocatalytic Hydrogen Evolution Systems
발표자함가영 (경북대학교)
연구책임자손창윤 (Seoul National University), 조새벽 (Sungkyunkwan University (SKKU)), 정대성 (Pohang University of Science and Technology (POSTECH)), 차효정 (경북대학교)
Abstract
Organic semiconductors (OSCs) are important photoactive materials for organic photovoltaics (OPVs) and photocatalytic hydrogen evolution. This study reveals a paradoxical behavior in which OSCs optimized for efficient charge extraction in OPVs show reduced activity as photocatalysts in aqueous colloids. Nanoparticles (NPs) of PM6:Y6 and D18:Y5 were investigated to compare their photophysical properties in photovoltaic and photocatalytic environments. An inverse relationship was observed between thin-film power conversion efficiency and hydrogen evolution activity. Y5-based NPs exhibited stronger aggregation, longer exciton lifetimes, and slower hole transfer, indicating charge localization that favors interfacial redox reactions. D18 also showed higher photoluminescence quantum yield and reduced non-radiative recombination compared to PM6. These results identify long-lived localized carriers as a key factor governing OSC charge dynamics.