PHOTOLUMINESCENCE DYNAMICS OF POROUS SILICON - PICOSECONDS TO MILLISECONDS

We present results of the investigation of spectrally resolved photolu minescence decay in porous silicon on the time interval which spans se ven orders of magnitude. The luminescence decay can be interpreted in terms of a fast bimolecular recombination of free carriers in the core of silicon nanocrystallites and of a slow recombination of localized carriers in the surface states. The etching time of the samples has an effect on the relative weight of both components and on the dynamics of the slow recombination. We discuss the dependence of relevant param eters on the etching time of the samples.