Opportunities for Plasmonic Organic Photovoltaics Using Nonfullerene Acceptors
This review critically examines recent advances in plasmonic organic photovoltaics (OPVs) enabled by metal nanoparticles (MNPs), nanopatterns, and subwavelength nanogratings, with a specific focus on the transition from fullerene acceptor (FA) to nonfullerene acceptor (NFA) systems. When incorporated into hole transport layers (HTLs), electron transport layers (ETLs), active layers, or transparent electrodes, these nanostructures leverage localized surface plasmon resonance (LSPR) to enhance light absorption, exciton generation and dissociation, and charge transport. Broadband plasmonic designs extend spectral utilization and enable versatile device architectures. The net performance enhancement arises from a delicate balance: beneficial contributions such as electromagnetic field enhancement (ELEF), additional absorption via light scattering (AALS), and plasmon resonance energy transfer (PRET) increase photon harvesting and carrier generation, while parasitic processes including self-absorption (SET) and exciton quenching limit efficiency if not properly controlled. Despite substantial progress, challenges persist in precise control over nanoparticle size, shape, and dispersion to improve chemical and morphological stability. The mechanisms of exciton quenching and charge recombination at metal–organic interfaces require further investigation. Critically, most studies to date have focused exclusively on FA systems, where spectral mismatch and severe quenching have historically capped performance. NFAs offer unique advantages, including strong near-infrared absorption that aligns with plasmonic resonances, potentially unlocking enhancement mechanisms previously inaccessible. These insights provide a framework for understanding plasmonic effects in OPVs and highlight the prospective potential of plasmonic nanostructured designs to drive further performance improvements, particularly as the field shifts toward next-generation NFA-based OPV devices.