An experimental study of the luminescence time decay in porous silicon as a function of temperature, excitation, and observation energies is reported. The decay line shape is well described by a stretched exponential for a variety of experimental conditions. A hierarchy of waiting times for carrier hopping, of intersite distances, and of site energies result from the analysis of our data.

• Received 16 September 1993

DOI:https://doi.org/10.1103/PhysRevB.48.17625