Reflectance and crystallinity of silicon solar cells with LIPSS produced by XeCl excimer laser pulses

Abstract

Laser-induced periodic surface structures (LIPSS) were formed on silicon solar cell surfaces by using a XeCl excimer laser to irradiate them with nanosecond UV laser pulses in the fluence range 0.2–0.6 J/cm2 near the melting threshold fluence (Fth = 0.5 J/cm2) in air. We measured the reflectance of the silicon solar cells after laser irradiation and evaluated their crystallinity by Raman spectroscopy. We found that reflectance and crystallinity depended on laser fluence and number of pulses. For fluence of 0.5 J/cm2, the produced LIPSS contributed to a reduction of ΔR = 3.3% in reflectance at a wavelength of 500 nm. The crystallinity of the fine structures with reduced reflectance was maintained at laser fluences near the melting threshold.