Impact of solidification dynamics on crystal properties of silicon molten by a nanosecond laser pulse

In this study, we use pump-probe microscopy to examine the melting and solidification dynamics of silicon during and after a UV laser pulse with a duration of 30ns. Below the ablation threshold, we observe lateral melt front contraction velocities of up to 600ms−1. The peak velocities spatially coincide with a ring of lower crystallinity within the formerly molten area, as we show with spatially resolved Raman spectroscopy.