TIME-RESOLVED SPECTROSCOPY OF VISIBLY EMITTING POROUS SILICON

Time-resolved emission spectra and photoluminescence decay kinetics ar e analyzed in porous Si samples exhibiting a noticeable inhomogeneous broadening under steady-state selective excitation. The gated emission spectra are found to be substantially narrower compared to a steady-s tate one, with a pronounced redshift with time. Considerable dependenc e of the decay parameters upon the emission wavelength is found. The d ecay time distribution analysis applied leads to a model where the non radiative decay mechanism is attributed to traps of the same type, the number of traps per Si grain obeying the Poissonian statistics.