Time-resolved measurements of the photoluminescence of Cu-quenched porous silicon

We have performed time-resolved photoluminescence measurements in the submicrosecond to microsecond time regime on porous silicon samples under several diffusion-based chemical treatments with copper ion solutions that produce varying crystallite surface conditions. Our results for short emission wavelengths emanating from high lying states indicate that Cu acts largely on the population process commencing from the top of the well at short relaxation time scales immediately after excitation, and to less extent on the radiating states in the microsecond regime.