Highly Efficient and Stable CdSe/CdS Quantum Dot–Polyurethane Acrylate Composite Fluorescent Antennas for Optical Wireless Communication

Fluorescent antennas (FAs) serve as promising optical concentrators for optical wireless communication (OWC) by overcoming the Étendue limit. Quantum dots-polymer nanocomposites exhibit superior optical properties for FAs. However, the poor chemical affinity between the surface ligands of quantum dots (QDs) and the polar functional groups in polymer matrices reduces interfacial compatibility, triggering ligand desorption and interparticle aggregation during photopolymerization. These effects severely degrade the photoluminescence efficiency and long-term stability, thus limiting the practical application of polymer-based FAs. Herein, a high-performance nanocomposite is demonstrated by embedding ODPA-passivated CdSe/CdS QDs into a polyurethane acrylate (PUA) matrix through doctor-blade coating and photopolymerization. Molecular dynamics simulations and density functional theory calculations reveal that QDs improve interfacial compatibility with PUA matrix through hydrogen-bond crosslinking between surface ligands and PUA hard segments, along with alkyl chain-induced plasticization of soft segments. Optimizing the QD concentration results in nanocomposites with a near-unity photoluminescence quantum yield of 99.15% and enhanced environmental stability. The sandwich-structured FA demonstrates a −3 dB bandwidth of 8.6 MHz, a 154 Mbps data rate using orthogonal frequency division multiplexing (OFDM) modulation. This work presents a readily processable nanocomposite system with high efficiency and stability, advancing OWC applications in terrestrial and underwater environments.