Laser Fluence and Scanning Speed Influence on Nanoparticle Aggregation and Surface Morphology

The aggregation of nanoparticles resulted in the replacement of the ripple period as the laser fluence increased from 2.53 J/cm2 to 3.79 J/cm2, and subsequently changed to V-grooves at a laser fluence of 5.06 J/cm2. Nevertheless, the ablation depth decreased as the scanning speed increased from 50 μm/s to 400 μm/s, leading to a shift in surface morphology from V-grooves to the micro-nanostructures array once again.