A study of the correlation between ultraviolet and infrared emission in Ni-doped SiOx films

The correlation between ultraviolet and infrared emission in Ni-doped SiOx (1 < x < 2) films has been investigated. Due to the presence of nickel, the maximum intensity of UV emission was obtained after annealing at 800 deg. C, which was explained by the formation of oxygen excess defects in the oxireduction reaction between Ni and SiOx. However, the intensity of infrared emission increases with the increase of annealing temperature and so does the mean size of SiO2 clusters characterized by scanning electron microscopy. An oxireduction reaction model was proposed to explain the correlation between ultraviolet and infrared emission in this system. The mean size of Si nanocrystals annealed at 1000 and 1100 deg. C was obtained from Raman spectra, which is in good agreement with the estimation by the PL peak shifts, based on quantum confinement effects