Abstract <p>Efficient light-trapping mechanisms are crucial for broadband light absorption enhancement in thin-film silicon (Si) solar cells since they exhibit weak light absorption. This study introduces an economical and efficient light trapping structure, consisting of a thin anti-reflective layer of silicon nitride (Si₃N₄) and a periodic array of embedded copper (Cu) nanospheres (NSs) in the Si active layer. This structural design is intended to facilitate the entry of sunlight into the cell with reduced reflection and to intensify the absorption of the received light within the 400–1100 nanometer (nm) wavelength spectrum. Comprising Si, the active layer is integrated with strategically placed Cu NSs to enhance the absorption of light through localized surface plasmon resonances (LSPR). This work involves three-dimensional finite difference time domain (FDTD) simulations to evaluate surface transmittance, light reflectance, and absorption in the Si thin-film. The outcomes from the numerical simulations demonstrate that this structure induces heightened light absorption, leading to a notable 60.02% increase in short-circuit current density (<i>J</i>_sc) compared to a conventional thin-film Si solar cell (i.e., bare Si).</p>