Observation of waveguide Fabry-Perot lasing in highly efficient Si nanocrystals

•A luminescent Si nanocrystal film with photoluminescence quantum yield > 70% was prepared by hydrogen sesquioxane (HSQ) and high-pressure hydrogenation.•This work demonstrates a waveguide Fabry-Perot lasing in such Si nanocrystals by observing the lasing characteristics of threshold behavior, spectral narrowing, polarization effect and small emission angle.