Thermoplasmonic Response of Non-Noble Metal Core–Shell Nanostructures for Solar Energy Harvesting

Core–Shell plasmonic nanostructures are drawing significant interest for its multifunctionality in light-harvesting; however, the mechanisms of the structure–performance relationship of non-noble metal materials are not yet fully elucidated. Here, finite element method (FEM) is employed to simulate the thermoplasmonic performance of X@Fe₂O₃(X = Bi, Ni, Co, Al) core–shell nanoparticles and analyze the influence of interparticle spacing and shell thickness on thermoplasmonic behavior with different structures. With Fe₂O₃ shell, monomers exhibit strong plasmonic features within visible regions and resonances peak redshift as shell thickness increases, and certain shell thickness can enhance the intensity of the resonances peak. Longitudinally polarized dimers exhibit strong interparticle coupling, resulting in pronounced field-heat hotspot alignment that promotes efficient light-to-heat conversion. Conversely, transverse polarization causes spatial decoupling between electromagnetic and thermal responses. The simulation results indicate that for 100 nm nanoparticles, maximum absorption efficiency does not always correspond to peak temperature response, underscoring the need to consider both spectral and spatial factors in thermoplasmonic design. This study provides important insight into the potential of non-noble metal-based core–shell nanostructures for solar energy harvesting.