Translucent Si Solar Cells Patterned with Pulsed Ultraviolet Laser Beam

Abstract

We report an application of a pulsed ultraviolet (UV) laser (λ = 355 nm) in producing translucent Si solar cells. This process efficiently generates a densely packed microhole array on a fully fabricated Si P-N junction solar cell in just a few minutes. Herein, prototype cells with a nominal microhole diameter of 23 μm with a spacing between 60 and 300 μm are fabricated. High-resolution electron-beam microscopy reveals that the UV laser beam introduces amorphized silicon oxide (SiO_x) in proximity to the patterned microholes via localized heating in air. Quantitative photovoltaic (PV) analysis shows a decline in the open-circuit voltage (V_oc) and the fill factor (FF) of the cells with the increase in the microhole density, likely due to the P-N junction damage during the laser beam irradiation. Despite the reduction in V_oc and FF, the solar cells retain a short-circuit current density (J_sc) above 90% without post-processing. The inherent microhole geometry associated with the laser beam profile allows multiple light scattering within the confined microhole structure, enhancing the translucency of the cells. While further development is required for optimization, these findings support the potential use of UV laser beams for fast and scalable production of translucent solar cells.