Nanosecond time-resolved emission spectroscopy from silicon implanted and annealed SiO2 layers

Photoluminescence decay curves and nanosecond time-gated spectra were measured from silicon implanted ${\mathrm{SiO}}_{\mathrm{2}}$ layers after thermal annealing. Different ion fluences and annealing times were tested. Three components emitting blue-green light with lifetimes of about 0.4, 2, and 10 ns were detected. The peak position of all components moves to longer wavelengths upon increasing the ion fluence. This short-wavelength emission seems to be related to the presence of extended defects acting as precursors of nanocrystals. A slower (microsecond) component, centered in the near infrared and attributed to nanocrystals, was also identified in the highest fluence implant considered ${\text{(3×10}}^{17}\hspace{0.5em}{\mathrm{cm}}^{\mathrm{-2}}\mathrm{).}$