Plasmonic nanostructured thin-film solar cells with Si₃N₄NPs/TiO₂ ARC and embedded AlNWs for enhanced light absorption

This work presents a novel thin-film silicon solar cell design that synergistically integrates plasmonic aluminum nanowires (AlNWs) and silicon nitride nanoparticles (Si 3 N 4 NPs) encapsulated within a titanium dioxide (TiO 2 ) antireflection coating (ARC). The proposed structure, employing a 3 µm thick crystalline silicon active layer, leverages strong light–matter interactions enabled by sub-wavelength plasmonic and scattering effects to enhance optical absorption across the visible and near-infrared spectra. Plasmonic AlNWs embedded beneath the silicon surface serve as light-trapping elements, while the Si 3 N 4 /TiO 2 ARC minimizes surface reflection. Optical and electrical characteristics were analyzed using finite-difference time-domain and drift-diffusion simulations, respectively. The design achieves a V oc of 0.56 V, a fill factor (FF) of 0.81, a short-circuit current density ( J sc ) of 43.12mA/cm 2 , and a power conversion efficiency (PCE) of 19.63% under normal incidence. Furthermore, the structure maintains strong performance at oblique angles, with the polarization-averaged PCE exceeding 10.68% at an incidence of 50°. The FF remains stable (0.81–0.80) across all angles, underscoring efficient charge extraction. These results demonstrate the potential of nanostructure-integrated architectures for high-efficiency, optically thin photovoltaic devices.