Nanosecond (ns) pulsed laser irradiation of the Si-nanocrystals/water colloids causes the selective heating of the Si-NCs accompanied by the formation of spherical particles. Femtosecond (fs) laser pulsed irradiation induces the formation of colloidal Si nanocrystals with peculiar surface chemistry (J Phys Chem C 120, 2016, 18822).