Fig. 2From: Silicon Substrate Strained and Structured via Cavitation Effect for Photovoltaic and Biomedical ApplicationTypical AFM images of the surface evolution during the 6-MHz sonication (15 W/cm2) of Si samples from the second group. a 10 min treatment in LN2, RMS roughness is ~8 nm; b 20 min treatment in LN2, RMS roughness is ~35 nm; c 35 min treatment in LN2 Back to article page