Picosecond laser texturization of mc-Silicon for photovoltaics: a comparison between 1064 nm, 532 nm and 355 nm radiation wavelengths

Self-organized surface structures were produced by picosecond laser pulses on multi-crystalline siliconfor photovoltaic applications. Three different laser wavelengths were employed (i.e. 1064 nm, 532 nmand 355 nm) and the resulting morphologies were observed to effectively reduce the reflectivity of thesamples after laser irradiation. Besides, a comparative study of the laser induced subsurface damage gen-erated by the three different wavelengths was performed by confocal micro-Raman, photoluminescenceand transmission electron microscopy. The results of both the structural and optical characterizationshowed that the mc-Si texturing performed with the laser at 355 nm provides surface reflectivity between11% and 8% over the spectral range from 400 nm to 1 m, while inducing the lowest subsurface damage,located above the depletion region of the p-n junction.