Efficiency Enhancement of Photovoltaic Devices via Low-Heat Laser Contact Opening Using a 193 nm ArF Excimer Laser

The advancement of ultra-thin photovoltaic devices is often constrained by limitations in conventional pulse laser processing, such as irregular ablation profiles, debris generation, and narrow process windows resulting from Gaussian beam characteristics. These challenges lead to uneven energy distribution and thermal damage, compromising device performance. In this study, we present a novel approach utilizing a 193 nm ArF excimer laser for non-thermal laser contact opening (LCO) to improve energy uniformity and minimize heat-affected zones in 100-μm-thick, 6-inch single-crystal silicon solar cells. The excimer laser enables large-area, uniform ablation with reduced substrate damage, in contrast to traditional 1064 nm picosecond lasers. Comparative analysis demonstrated that the excimer-based LCO achieved a 1.04% increase in fill factor (from 78.92% to 79.96%) and a 0.35% improvement in power conversion efficiency (from 19.79% to 20.14%), along with a reduction in series resistance by 0.00054 Ω. These improvements are attributed to enhanced LCO width uniformity and edge definition. This work highlights the significant potential of excimer lasers for precision back-contact structuring in high-efficiency, thin-film photovoltaic technologies. Future work will further refine LCO parameters and explore broader applications in next-generation solar cell designs.