Monoexponential Microsecond Decay of Blue Photoluminescence in Aged Porous Silicon Prepared with Ar⁺ 488nm

Blue photoluminescence is observed in aged porous silicon samples anodized under Ar⁺ 488 nm laser illumination. No samples have been undergone any heating treatment process. Both nanosecond and microsecond decay of blue photoluminescence have been measured. Samples show a good monoexponential microsecond decay with lifetimes of about 5.3μs . Photoluminescence excitation spectra of blue and red Photoluminescence indicate there is a large Stokes shift (about 800-900meV) in the excitation spectra of red photoluminescence while no this marked Stokes shift in that of blue photoluminescence. The possible origin of the photoluminescence is discussed based on the experimental results.