Dual-Layer SiN_x/SiO₂ as Antireflective Coatings for Optical and Electrical Enhancement in Passivated Emitter and Rear Contact Solar Cells

In this study, the impact of antireflective coatings (ARCs) on the optical and electrical performance of passivated emitter and rear contact (PERC) solar cells, comparing single-layer SiN_x ARC with an optimized double-layer SiN_x/SiO₂ ARC (DLARC), is investigated. The findings demonstrate that simulated SiN_x DLARC significantly reduces optical reflection losses, enhances photon absorption across a broad spectral range, and improves carrier collection efficiency. Numerical simulations reveal a 0.55% absolute efficiency gain, with the double-layer ARC achieving a power conversion efficiency (PCE) of 22.14%, compared to 21.59% for the single-layer SiN_x ARC. Furthermore, experimental validation confirms a PCE of 21.10% for the fabricated PERC cell with a single-layer SiN_x ARC, closely aligning with the simulated results. The improved external quantum efficiency, particularly in the short-wavelength region (300–600 nm), confirms the superior light-trapping capability of the simulated DLARC. Further optimization of layer thickness (t) and refractive index (n) enhances impedance matching at interfaces, leading to better spectral utilization and reduced optical losses. Herein, the potential of double-layer ARCs is highlighted to advance the development of high-efficiency PERC solar cells offering significant improvements in light absorption and overall device performance.