Amphiphilic Polymer Conetworks for Non-Fullerene Organic Solar Cells: Regulated Molecular Stacking Enables Efficient Downconversion

초록

Amphiphilic polymer conetworks (APCNs), composed of nanoscale phase-separated hydrophilic and hydrophobic domains, have recently attracted interest for passive photonic applications like wearable luminescent solar concentrators. Here, their utility is extended by integrating APCNs into the active layer of organic photovoltaics (OPVs), enabling the incorporation of down-conversion luminophores that are otherwise incompatible with conventional OPV architectures. The APCN scaffold confines hydrophilic luminophores within hydroxyl acrylate domains, while the hydrophobic PM6:Y6 bulk heterojunction (BHJ) resides in the polydimethylsiloxane domains. Luminophores are chosen for selective phase affinity and complementary absorption to the BHJ. Devices incorporating dicyanomethylene-4H-pyran (DCM) luminophores show enhanced photocurrent, with short-circuit current increasing from 25.7 to 27.3 mA cm-2, while maintaining an open-circuit voltage of 0.86 V. Transient absorption spectroscopy reveals delayed ground-state bleach in PM6 and Y6, consistent with efficient exciton replenishment via energy transfer from luminophores. Grazing-incidence wide-angle X-ray scattering shows that luminophore molecular planarity and dihedral angles influence BHJ packing via van der Waals interactions, impacting charge transport. This work presents a multifunctional approach to enhance optoelectronic devices by embedding functional moieties within APCNs, offering insights from photonic, optoelectronic, and structural perspectives and establishing APCNs as a versatile platform for next-generation device engineering.

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