Change in reflectance of silicon wafer with different micro-patterned surface fabricated using fiber laser

Abstract

Laser-patterned surfaces functioned as antireflecting surfaces, which minimized reflection loss for a crystallized silicon wafer. Four different microstructures, namely, micro-channel, micro-hole, grid, and hybrid patterns were fabricated using the fiber laser. The patterned wafers were characterized for the wavelength range of 300–1,100 nm. The hybrid structure exhibited the lowest average reflectance of 0.33, followed by the micro hole (0.36) and the micro-channel (0.4) for the 300–1,100-nm wavelength using a Jasco V-770 spectrophotometer (Japan Spectroscopic Company (JASCO), Japan). Patterned surfaces can trap a large amount of light in solar panels, which is beneficial for photovoltaic and optical applications by cutting down the reflection losses. Surface morphology analysis was performed using a field emission scanning electron microscope (SEM). SEM images showed an amplified view of structure where the irregularity of surfaces (micro cracks, ripples, pits, etc.) can be seen.