Enhancement and stability of photoluminescence from Si nanocrystals embedded in a SiO2 matrix by H2-passivation

•We study the H2-passivation of Si-NCs/SiO2 for enhanced and stable light emission.•H2-passivation is effective to passivate dangling bonds and enhance luminescence.•The effects of passivation on the PL show saturation with time and temperature.•The effects of passivation on the luminescence are reversible.•Si-NCs/SiO2 exhibit stable passivation and depassivation behaviors.