Abstract
Hole-net structure silicon is fabricated by laser irradiation and annealing, on which a photoluminescence (PL) band in a the region of 650–750 nm is pinned and its intensity increases obviously after oxidation. It is found that the PL intensity changes with both laser irradiation time and annealing time. Calculations show that some localized states appear in the band gap of the smaller nanocrystal when Si = O bonds or Si–O–Si bonds are passivated on the surface. It is discovered that the density and the number of Si = O bonds or Si–O–Si bonds related to both the irradiation time and the annealing time obviously affect the generation of the localized gap states of hole-net silicon, by which the production of stimulated emission through controlling oxidation time can be explained.