Enhancing Efficiency of <scp>GaAs</scp> Thin‐Film Solar Cells via Gold Nanoparticle‐Induced Localized Surface Plasmon Resonance

ABSTRACT This study explores the enhancement of light trapping in photovoltaic devices through the synergistic integration of localized surface plasmon resonance (LSPR) effects from gold (Au) nanoparticles (NPs) and photonic crystal (PhC) structures. By embedding plasmonic Au NPs within the active layer of a gallium arsenide (GaAs)‐based thin‐film solar cell, and systematically optimizing their size and spatial distribution, significant improvements in both photo‐absorption and photon‐to‐electron conversion efficiency were achieved. Finite‐difference time‐domain (FDTD) simulations were utilized to model the propagation of electromagnetic waves under AM1.5 solar illumination, guiding the optimization of the device architecture. The optimized configuration, comprising spherical Au NPs embedded in the GaAs active layer, demonstrated an average optical absorption of 89% across the 300–880 nm wavelength range, with peak absorption reaching 93.78% between 400 and 880 nm. This translated to a notable increase in photo‐conversion efficiency (PCE) to 30.697% and a short‐circuit current density (J SC ) of 33.601 mA/cm 2 . Compared to reference devices without Au NPs, these enhancements represent relative improvements of 5.7% in PCE and 5.4% in J SC , attributed to intensified local electric fields induced by LSPR. Furthermore, a fivefold enhancement in the maximum carrier generation rate per unit volume was achieved in the plasmonic NP integrated devices. These findings provide a robust theoretical foundation and valuable insights for the design of high‐efficiency plasmonic nanoparticle‐embedded thin‐film solar cells.