Regulating Polymeric Adsorption Dynamics via Monolayer-Architected Hydrotalcite Integration for High-Performance Organic Solar Cells.

Abstract

In organic solar cells (OSCs), the molecular aggregation property of donor-acceptor bulk heterojunction (BHJ) architectures serves as a critical determinant in device performance. Nevertheless, the intrinsic steric constraints imposed by polymeric side chains frequently lead to metastable molecular packing configurations with diminished structural coherence. In this study, a morphological modulation strategy is proposed by adopting a 2D layered hydrotalcite (HDC) nanocrystal to regulate polymeric adsorption dynamics. By leveraging hydroxyl-directed interfacial coordination to HDC matrices, the nanocrystal-integrated BHJ systems manifest a pronounced donor-phase H-aggregation, synergistically coupled with reduced π-orbital overlap distances and enhanced long-range crystalline ordering. These nanoscale structural advancements collectively engender superior charge transfer kinetics with reduced activation energy barriers and improved charge carrier transport properties. The HDC nanocrystal-blended devices not only achieve a top-notch power conversion efficiency (PCE) of 20.63%, but also shows its applicability across various donor - acceptor BHJ systems. This work develops a crystal-engineering strategy that concurrently optimizes nanoscale morphology and charge transport networks in OSCs, yielding state-of-the-art device performance through synergistic structural-electronic modulation.